: Northstar Repair without inserts



97EldoCoupe
10-30-08, 05:54 AM
Photo of one of my studded blocks - this completely eliminates the need for inserts...

http://www.northstarperformance.com/img/studs3.jpg

This can be done even on engines that have had timeserts before. They are custom machined.

AJxtcman
10-30-08, 07:52 AM
Photo of one of my studded blocks - this completely eliminates the need for inserts...

http://www.northstarperformance.com/img/studs3.jpg

This can be done even on engines that have had timeserts before. They are custom machined.

What size threads are the stud portion that are in block?
11mm X 1.50mm will not hold and I can see that is not what those are.

Studs will pull out of the block unless the thread pitch is changed and I am not 100% on board with that.
Are you going to take some torque out of the head now? :thumbsup:

97EldoCoupe
10-30-08, 08:14 AM
That's believe it or not 5/8" UNC in the block and 1/2" UNC coming out of the block. These studs have more grip in the block than anything else out there. The reason I do it this way is because when torquing down the heads, the torquing is done with nuts on top (steel on steel) so you're not twisting a bolt into aluminum threads under torque. This is a lot safer for the block. I'd bet every last dollar I have that it would take 20+ years for these studs to pull out of the block, probably more. They're all countersunk approx. 1/8" below the deck surface.

97EldoCoupe
10-30-08, 08:17 AM
I've been torquing them at 80 ft. lbs. The studs are high alloy, they will handle it. To be safe I'd recommend staying at approx. 75 ft. lbs.

Torquing the heads at factory spec (M11 x 1.5) you give it 22 ft. lbs. (if I remember correctly) and three rotations of 60 degrees. According to my torque wrench that wound up being 60 ft. lbs. when all was done.

And yes, that is a 4.0 Aurora block. The only difference between the 4.0/4.6 is the bore size (and some casting #s)

sofireguy
10-30-08, 08:52 AM
Wow. I want to see how this turns out. Do you think it will work with the 4.6L Northstar?? Where did you get those studs and where did you have that done? I want to maybe see how that would turn out on my current Seville engine after I pull it and replace it with another engine. It would be a back-up engine.

I always thought that it would be smart to use studs rather than bolts either way on any engine?? Then again, it is an aluminum block.

97EldoCoupe
10-30-08, 10:09 AM
I've done this on many cars already- 4.6 Northstars too. I custom machined them using my lathe. It is a good idea on any engine, but especially the Northstar, because when you go to torque the heads, it already has good grip in the block. You're no longer turning the bolt in the block when you're torquing. Instead, it will just "pull" on the stud. And there's no chance of pulling the stud up or damaging the new aluminum threads in the block by torquing. It's one piece all the way up, rather than a skinny fine-thread bolt being threaded into an insert.

sofireguy
10-30-08, 10:17 AM
Mind sending me an E-mail?

sofire70@yahoo.com

Edit: I can't send private messages.

sofireguy
10-30-08, 11:43 AM
I saw that you were making kits for this on another thread. I was wanting to possibly look into your kit that you have come up with.

97EldoCoupe
10-30-08, 01:27 PM
Email sent Sofireguy.

STSj90
10-30-08, 01:32 PM
Nice! Let us know EXactly what was done please! Step by step. Please. I would love to do this on my N* if the HG's go. Looks preeeeettyy:yup::thumbsup:

let us know the full cost also please. How are the northstars holding up that had this done? And what kinda people are driveing them? I hope they have been tested under Hard conditions.

AJxtcman
10-30-08, 01:39 PM
I've been torquing them at 80 ft. lbs. The studs are high alloy, they will handle it. To be safe I'd recommend staying at approx. 75 ft. lbs.

Torquing the heads at factory spec (M11 x 1.5) you give it 22 ft. lbs. (if I remember correctly) and three rotations of 60 degrees. According to my torque wrench that wound up being 60 ft. lbs. when all was done.

And yes, that is a 4.0 Aurora block. The only difference between the 4.0/4.6 is the bore size (and some casting #s)

1993-1999 Head Bolt Torque

First Pass ----- 30 lb ft
Second Pass -- +70
Third Pass ---- +60
Fourth Pass -- +60 (190 Degrees total)


I think we are looking at this 2 separate ways.

Lets say the head is 78mm thick from the deck to the top of the bolt hole @ 72
I feel that the growth of the head in this area is too great @ 225 for a hardened stud and stock thread pitch.

Lets say it grows 1mm. I know it should be that much. What would the weak link be?
I feel that the weak link is the material used in casting the Block.

Will the 5/8 nc inserts work with hardened studs? I would think this would be determined by the cut and clearance of the insert and the block.

97EldoCoupe
10-30-08, 03:01 PM
AJ according to what you posted on the Fiero Forums, it's 22 ft. lbs., then three turns of 60 degrees. Also, I see what you're getting at with the heat expansion thing. What about the stock head bolts? They're hard steel as well. Thermal expansion is something we won't get away from.

These are studs - no inserts at all.

My 97 Eldorado and my 98 STS are both running these studs in the block. My '98 STS is the VIN 9 300 hp engine. I run that thing hard. If I break it by running red-line when ever I feel like it, I know I can fix it. So I'm not worried. It's about a year and a half ago that I did the work on my '97 Eldo, still running strong. My 98 was done 8 months ago. No issues. Not a temperature spike, no coolant loss, Nothing. On either car. Both cars have overheated since due to a blown heater hose on the STS and a water pump belt on the Eldo. Fixed them both, same head gaskets, NO ISSUES. Both cars get WOT when ever my right foot gets itchy. I've done a number of customers cars with these studs, some are even on these forums. I've done the HGs on quite a few Cadilacs & Auroras- #38 is in my shop, ready to fire up. Only one complaint of an overheating engine since. And that car had a bad thermostat. Swapped in a new one, and it was good to go. No HG failures. That's a record I have planned to keep.

The aluminum will ALWAYS be a weak link. So we fix the blocks the best way we know how. Some will say inserts/timeserts/norms, I say one piece, solid steel studs.

97EldoCoupe
10-30-08, 03:09 PM
I checked the FSM and it is 22 ft. lbs., and three turns of 60 degrees.

STSj90
10-30-08, 04:35 PM
Awsome man, Glad to hear its holding up good. You know what would be cool..Is to open up one of the studded northstars after like 100,000 miles or more to check everything CLOSLY.. Would be cool to do that. I know its not easy to just pull the engine to check stuff out and is kinda retarded in a way. But i think it would be Plane AWESOME!

Or could check it after 200,000 or 150,000 miles. If all is well and looks damn good. You could post up pics and info and say ''this is one of our engine's after xxx,000 miles.''

:highfive:

mighty_quad4
10-30-08, 06:11 PM
I've done this on many cars already- 4.6 Northstars too. I custom machined them using my lathe. It is a good idea on any engine, but especially the Northstar, because when you go to torque the heads, it already has good grip in the block. You're no longer turning the bolt in the block when you're torquing. Instead, it will just "pull" on the stud. And there's no chance of pulling the stud up or damaging the new aluminum threads in the block by torquing. It's one piece all the way up, rather than a skinny fine-thread bolt being threaded into an insert.

what do you, or will you ever, charge for the studs?

sassanach
10-30-08, 06:43 PM
always a pleasure to see that there are still some genuine craftsmen left in the world:thumbsup:

97EldoCoupe
10-30-08, 07:18 PM
For the whole kit, studs, drill and tap blocks (guides), instructions, drill bit and tap, $500 CAD. Thats $416.53 USD according to the exhange rate as it stands right now. Shipping is $50 extra for now. When and if I start selling these, the price will likely drop if the demand increases.

I'm currently designing a new drill/tapping guide that will allow you to drill all 10 holes at once to save time. It would save me a lot of time.

I'd love to take one apart at 100,000 miles after repair to see what it looks like. I have a ways to go till that mileage. But yes that would be cool!

Also, I recommend to anyone who has N* cars- change your coolant. The more the better. I've seen what DexCool does to the HGs. They rust and corrode. Coolant is dirt cheap compared to HG jobs and blocks. Do it every two years. If you're in love with your Northstar powered car as much as I am, every year wouldn't even hurt. I'm not saying you'd have to, but as others have mentioned in the forums, coolant is cheap.

blue_eldo
10-30-08, 07:32 PM
Just as a little history, Porsche had a well know problem with cylinder head studs pulling out of the case on their 2.7 liter flat air cooled six in 74 thru 77 prior to the introduction of the 3.0 SC engine. These engines were the first to use aluminum cylinders and the differential expansion of the steel studs and the aluminum case and cylinders was the root cause. The went to an alloy callled Dilavar that has a coef on expansion half way between steel and aluminum. This stuff is very sensitive to corrosion cracking and requires a protective epoxy coating. It took Porsche four years to solve their problems.
Studs are the way to go. Any race engine that has to be re-assembed on a continous basis is retrofitted to studs.

97EldoCoupe
10-30-08, 07:46 PM
The issue with steel studs and aluminum blocks/heads cannot be resolved. Either you're using bolts or studs, either way they're still steel. The reason I'm using studs is because I can have them larger in the block than the part that's passing through the heads. You can't do that with bolts unless you use inserts, and inserts of any kind are just not my idea of the best way to repair an engine. Studs allow me to drill and tap the holes in the block for larger coarse thread, and still keep the "one piece" benefits of a bolt.

Not to mention the fact that the part that goes in the block are already in there when you start torquing- the torquing is now done on top of the engine. Steel on steel.

Bi-metal dilemma... Aluminum head bolts?:hmm::histeric:

Like I said- either way, it's steel holding the heads down on the block. Either it's a bolt, or a stud. Same difference.

creeker
10-30-08, 08:55 PM
For the whole kit, studs, drill and tap blocks (guides), instructions, drill bit and tap, $500 CAD. Thats $416.53 USD according to the exhange rate as it stands right now. Shipping is $50 extra for now. When and if I start selling these, the price will likely drop if the demand increases.

I'm currently designing a new drill/tapping guide that will allow you to drill all 10 holes at once to save time. It would save me a lot of time.

I'd love to take one apart at 100,000 miles after repair to see what it looks like. I have a ways to go till that mileage. But yes that would be cool!

Also, I recommend to anyone who has N* cars- change your coolant. The more the better. I've seen what DexCool does to the HGs. They rust and corrode. Coolant is dirt cheap compared to HG jobs and blocks. Do it every two years. If you're in love with your Northstar powered car as much as I am, every year wouldn't even hurt. I'm not saying you'd have to, but as others have mentioned in the forums, coolant is cheap.

Do you have an alternative to dex-cool,or do you use it and change it regularly?.

Ranger
10-30-08, 08:58 PM
I've seen what DexCool does to the HGs. They rust and corrode.
I don't mean to start an argument, because I am by far not an authority and I am sure you have much more experience than I, but I find that hard to believe. If that where the case, wouldn't every GM engine have head gasket problems? Would it not affect the thermostat gasket as well, or any other gasket that comes in contact with coolant? I'm more of AJ's opinion that it is more of a metallurgy problem. Just my $.02 FTIW.

sofireguy
10-30-08, 10:04 PM
DexCool is some nasty stuff.. It's messed both of my GM vehicles cooling systems. One being the Venture with the 3.1L. First the intake manifold gasket went, then the head gasket went a month later. And now my poor Seville. ='(.. I switched to "green-stuff" after the head gasket job for my Venture and no problems since.

We tried to switch when we heard the Northstar engines had HG problems, but it was too late. When we changed the water pump before moving to a different coolant, the blades on that sucker we GONE. Eaten up. We had switched up to the BMW "gold blend" of coolant after that. It really cleaned up the cooling system.

Talk to a GM tech, he will tell you that Dexcool is nasty.

97EldoCoupe
10-30-08, 10:10 PM
No Ranger by all means thats what these forums are for- to openly discuss these topics.

That may very well be- but I see the actual head gaskets rusting and flaking. The expanding and contracting heads/block, combined with the large open water jackets around the cylinders, works on the head gaskets- that's true. But why are they rusting? Almost every one I've seen is rusted, and parts of the gasket are stuck in the block sometimes. I've heard it from other mechanics too that the DexCool is the cause. I'm not going to bet my life on it, but I won't recommend Dex-cool either. I don't trust it. Coolant is supposed to protect against corrosion. From what I've seen, the cars that have been maintained by GM, running Dex-cool, are the worst.

I'm using Prestone's "Long Life GM Dexcool Approved" Coolant. Safe for aluminum, Prestone brand, orange in colour. Then mix it 50/50 with de-ionized/distilled water.
If it's true that coolant loses it's corrosion inhibitors, there's a great reason to change it more often.

In all honesty if you can drive a car for 10 years on one set of head gaskets, I'd say that's pretty good. If the head gaskets in every engine I work on lasts another 10 years, I'm happy with the results of my work. And if the head gaskets ever need to be done again, the threads in the block should still be OK. I'll know 10 years from now.

97EldoCoupe
10-30-08, 10:18 PM
I'm sure there are more people out there that think like me- "small fine threads at the end of the head bolts, and Dex-Cool coolant make a bad combination".

Another thing- "the classic topic" some head bolts are swimming in filthy darkened coolant. The aluminum threads are literally eaten away. Antifreeze/Coolant is supposed to protect metal against corrosion. If the blocks are porous, and coolant is getting around the threads, really it shouldn't harm the bolts in any way. But the coolant is eating the threads??!!!! That tells you right there. Bad coolant.

creeker
10-30-08, 10:54 PM
97eldocoupe, thanks for your time and explanations,very informative, you talked about dex-cool and long life g.m. dexcool (orange) approved, I thought all "dexcool" was orange,what color is the stuff you say causes corrosion?. I am using the green stuff in my 92 eldo. 4.9 and the orange stuff in my 97 sts 4.6.

sofireguy
10-31-08, 12:12 AM
So the Orange stuff by "Prestone" isn't actually "Dexcool"?? I thought they were the same? I still might use "green" or BMW "gold".

Ranger
10-31-08, 10:41 AM
I'm sure there are more people out there that think like me- "small fine threads at the end of the head bolts, and Dex-Cool coolant make a bad combination".

Another thing- "the classic topic" some head bolts are swimming in filthy darkened coolant. The aluminum threads are literally eaten away. Antifreeze/Coolant is supposed to protect metal against corrosion. If the blocks are porous, and coolant is getting around the threads, really it shouldn't harm the bolts in any way. But the coolant is eating the threads??!!!! That tells you right there. Bad coolant.
If coolant (any coolant) gets into the bolt holes, electrolysis will occur. Remember, you have dissimilar metals. Steel bolt in contact with an aluminum block. Add a liquid and you will have corrosion eventually. THAT is what is causing the corrosion, not the coolant.

97EldoCoupe
10-31-08, 11:10 AM
Thank you Ranger, that is something I haven't thought of- the electrolysis part. I've been using thread locker on the studs for two reasons- to seal the threads and to keep the studs in place. Coolant should not get into the threads at all.

97EldoCoupe
10-31-08, 11:12 AM
GM has their own coolant. Prestone is a different brand. They're the leader in coolant, so I'm assuming they have labs that make sure their coolant is safe for aluminum and head gaskets. I'll contact Prestone's lab and see what they say in regards to the coolant, Dex-Cool, head gaskets, aluminum engines, etc.

sofireguy
10-31-08, 11:16 AM
That would be great. Be sure to ask about the Green stuff ;-).. I know we've been running that in our 3.1L Venture for ~2 years now with no problems. I think the 3100 engine is aluminum.

dwight.j.carter
10-31-08, 11:29 AM
it's a nice idea I would like to see the long term result.

Ranger
10-31-08, 12:04 PM
Thank you Ranger, that is something I haven't thought of- the electrolysis part. I've been using thread locker on the studs for two reasons- to seal the threads and to keep the studs in place. Coolant should not get into the threads at all.
Yeah, thread locker should be used and even new bolts in the head gasket kit come with thread locker applied. You probably already know that.

I agree that coolant should never get into the threads. My belief (FWIW) is that the threads let go first. Then, once the clamping force is compromised, coolant gets past the gasket and into the threads, further exasperating the problem by electrolysis. When the engine is opened up, the gasket has had time to deteriorate and the bolts are all corroded and Dex gets falsely blamed. If Dex where eating gaskets like this, every gasket on every GM vehicle would have the problem and there are just too many running around at high mileage without it. My wife's '96 Bonneville (3.8) with over 150K on it has not had any problems (other than the infamous intake manifold) and it still has Dex in it. I may be way off base here, but I think Dex is getting falsely blamed when the problem lies else ware.

AJxtcman
10-31-08, 12:23 PM
AJ according to what you posted on the Fiero Forums, it's 22 ft. lbs., then three turns of 60 degrees. Also, I see what you're getting at with the heat expansion thing. What about the stock head bolts? They're hard steel as well. Thermal expansion is something we won't get away from.

These are studs - no inserts at all.


The OEM head bolts are not grade 8 bolts. They twist like a spring. The Main bolts are hardened bolts and they break all the time when removing or reinstalling.

I was referring to your Studs as inserts.

I think if you are doing it correctly with the correct tap this will hold up very well. I think this is a good idea. As soon as you said 1/2 NC I was game.

Norm's inserts are a little loose for me if I was using Hardened Studs. I think is the tap in the set. I am use to installing the TimeSerts and they fit tight.

AJxtcman
10-31-08, 12:28 PM
1993-1999 Head Bolt Torque

First Pass ----- 30 lb ft
Second Pass -- +70
Third Pass ---- +60
Fourth Pass -- +60 (190 Degrees total)


I think we are looking at this 2 separate ways.

Lets say the head is 78mm thick from the deck to the top of the bolt hole @ 72
I feel that the growth of the head in this area is too great @ 225 for a hardened stud and stock thread pitch.

Lets say it grows 1mm. I know it should be that much. What would the weak link be?
I feel that the weak link is the material used in casting the Block.

Will the 5/8 nc inserts work with hardened studs? I would think this would be determined by the cut and clearance of the insert and the block.


AJ according to what you posted on the Fiero Forums, it's 22 ft. lbs., then three turns of 60 degrees. Also, I see what you're getting at with the heat expansion thing. What about the stock head bolts? They're hard steel as well. Thermal expansion is something we won't get away from.

These are studs - no inserts at all.

My 97 Eldorado and my 98 STS are both running these studs in the block. My '98 STS is the VIN 9 300 hp engine. I run that thing hard. If I break it by running red-line when ever I feel like it, I know I can fix it. So I'm not worried. It's about a year and a half ago that I did the work on my '97 Eldo, still running strong. My 98 was done 8 months ago. No issues. Not a temperature spike, no coolant loss, Nothing. On either car. Both cars have overheated since due to a blown heater hose on the STS and a water pump belt on the Eldo. Fixed them both, same head gaskets, NO ISSUES. Both cars get WOT when ever my right foot gets itchy. I've done a number of customers cars with these studs, some are even on these forums. I've done the HGs on quite a few Cadilacs & Auroras- #38 is in my shop, ready to fire up. Only one complaint of an overheating engine since. And that car had a bad thermostat. Swapped in a new one, and it was good to go. No HG failures. That's a record I have planned to keep.

The aluminum will ALWAYS be a weak link. So we fix the blocks the best way we know how. Some will say inserts/timeserts/norms, I say one piece, solid steel studs.


I checked the FSM and it is 22 ft. lbs., and three turns of 60 degrees.

I better fix the spec on the Fiero Forum

TSB # 99-06-01-016: SMU - Cylinder Head Tightening Specification Clarification - (Oct 4, 1999)

1993-99 4.0 L or 4.6 L Engine (VINs C, Y, 9 -- RPOs L47, LD8, L37)


First Pass -- 40 Nm (30 lb ft)
Second Pass -- 70 Degrees
Third Pass -- 60 Degrees
Fourth Pass -- 60 Degrees (190 Degrees total)

creeker
10-31-08, 12:30 PM
I must be getting old or something,when I think I've finally got it right another thread comes up about coolant,I am using the prestone long life orange in my 97 sts,which seems to be the right stuff,
My question is, what should I be using in my 92 eldo. with a 4.9.

Thanks for any advice.

97EldoCoupe
10-31-08, 01:09 PM
I have had very little to do with the 4.9's. I believe they are cast iron heads, alumimum block engines. Odd combo, but I would say either type of coolant would be OK for the 4.9- green or orange. Maybe some others will chip in that have had more experience with the 4.9's.

97EldoCoupe
10-31-08, 01:33 PM
The OEM head bolts are not grade 8 bolts. They twist like a spring. The Main bolts are hardened bolts and they break all the time when removing or reinstalling.

I was referring to your Studs as inserts.

I think if you are doing it correctly with the correct tap this will hold up very well. I think this is a good idea. As soon as you said 1/2 NC I was game.

Norm's inserts are a little loose for me if I was using Hardened Studs. I think is the tap in the set. I am use to installing the TimeSerts and they fit tight.

You've got that right, the main bolts break. I've seen it. But the OEM head bolts ARE hardened steel. Yes, they twist like a spring, Because the bolt diameter is only .394 according to my dial caliper. That's between 3/8" and 7/16". I just tested one on a junk motor (cracked cylinder) with a worn out head, and it took over 100 ft. lbs. to snap that OEM bolt. And it didn't twist off. It snapped. That is hardened steel. They may not be grade 8, but they are hard.

The bolts thread in the block with little or no play- they are a tight fit. The only issue is tapping the block 100% straight because these are studs- they all have to be perfectly inline to slip the head over.

dkozloski
10-31-08, 08:29 PM
Common practice in the aircraft industry is to neck the studs down so that they act like a spring and stretch and shrink with temperature changes. In fact the original Cadillac head bolts do this also. That's why the threads run full length. Sometimes bellville cupped washers are used to provide the same effect.

Ranger
10-31-08, 08:48 PM
I must be getting old or something,when I think I've finally got it right another thread comes up about coolant,I am using the prestone long life orange in my 97 sts,which seems to be the right stuff,
My question is, what should I be using in my 92 eldo. with a 4.9.

Thanks for any advice.
The '92's had conventional silicated green coolant. You can still use the long life stuff, but you still have to change it every 2 years.

creeker
10-31-08, 09:44 PM
The '92's had conventional silicated green coolant. You can still use the long life stuff, but you still have to change it every 2 years.

Thanks ranger,if I switched to long life (orange) I guess i would have to remove all the green stuff first?, why would the orange stuff only be good for 2 years in the 4.9?.

Ranger
10-31-08, 10:25 PM
Yes, you want to flush all the green out first. My understanding, as our old Guru explained it, is that the silicates in the green coolant plate the inside of the water jacket and thus somehow (I don't fully understand it) negates the extended change intervals.

AJxtcman
10-31-08, 10:27 PM
You've got that right, the main bolts break. I've seen it. But the OEM head bolts ARE hardened steel. Yes, they twist like a spring, Because the bolt diameter is only .394 according to my dial caliper. That's between 3/8" and 7/16". I just tested one on a junk motor (cracked cylinder) with a worn out head, and it took over 100 ft. lbs. to snap that OEM bolt. And it didn't twist off. It snapped. That is hardened steel. They may not be grade 8, but they are hard.

The bolts thread in the block with little or no play- they are a tight fit. The only issue is tapping the block 100% straight because these are studs- they all have to be perfectly inline to slip the head over.

I under stand your point. They did not twist to a point when they broke. Hmmm
I guess that means it is harder than? :hmm:
I am with you on that. Maybe not 100%, but I can't argue that they aren't after that.

Hey I used a head bolt to make an eyelet for the cherry picker at the dealer a few years back. I made it, so the hole is round. The hole is still round maybe a few hundred engines latter, so I am with you on the harder than soft.

AJxtcman
10-31-08, 10:31 PM
Yes, you want to flush all the green out first. My understanding, as our old Guru explained it, is that the silicates in the green coolant plate the inside of the water jacket and thus somehow (I don't fully understand it) negates the extended change intervals.

Lots of http://i224.photobucket.com/albums/dd25/AJxtcman/smilies/gossip.gif at work about Dex-Cool. Not the same old chatter either.

I just removed Dex Cool from a non GM car and installed G05, but the car called for Dex Cool. :stirpot:

Ranger
10-31-08, 10:39 PM
All I can say is that I have had no problem with Dex. Then again I don't have your experience. Wish I knew what the truth is. Not sure we ever will.

creeker
10-31-08, 11:04 PM
Yes, you want to flush all the green out first. My understanding, as our old Guru explained it, is that the silicates in the green coolant plate the inside of the water jacket and thus somehow (I don't fully understand it) negates the extended change intervals.

What I meant was if used the orange stuff instead of the green stuff in my 4.9 would it have to be flushed in 2 years, or would it be good for
5 years?, and is it safe to use the orange in my 4.9 once it has had green in it?.

Ranger
11-01-08, 10:09 AM
It is safe to use, but no real reason to as it still needs to be changed every 2 years.

97EldoCoupe
11-01-08, 07:35 PM
I'm doing the HGs now on a car that I have proof has had Dex in it it's whole life. a '98 STS. Original engine. Original HGs. Until now. These are the worst I've seen yet.

Someone mentioned the fact that there's no issues with the 3.8 Buick engines, and they run Dex. I know those engines are like the old Olds 307's- they never die and other than the intake/egr ordeal, they never fail. No head gasket problems there.

BUT.......

The 3800 Series II Buick V6 is a cast iron block/cast iron head engine. There's no aluminum for the coolant to cycle through. Unlike the Northstar, all aluminum.

Is it possible that something in the aluminum alloy is triggering something in the Dexcool to make a corrosive "HG damaging" mixture? Just a thought...

I've seen N* engines with the second set of HGs, running on green coolant, not swollen or corroded at all. If the shops that had done the HGs would have fixed the bolt issue, (at least inserted the block) the HGs would have been alright on at least two of those cars with green coolant.

I have yet to confirm any of this, but this is just from what I've seen so far. I could be wrong.

97EldoCoupe
11-01-08, 07:46 PM
I under stand your point. They did not twist to a point when they broke. Hmmm
I guess that means it is harder than? :hmm:
I am with you on that. Maybe not 100%, but I can't argue that they aren't after that.

Cool! I used a head bolt on my special Northstar "hoist attatchment" to attatch a short piece of chain.... :highfive:

I tried bending one in the vice, and it bent a bit. So they're not as hard as a main bolt, but they are hardened. We're both right.

The washers- on the other hand, I was going to save the Williams washers from the head bolts. They're nice thick washers. Tried re-drilling one a bit larger. No way that's gonna work. Even put one in the lathe. Not even a lathe- cutter bit will touch it. The washers are extremely hard steel.

Ranger
11-01-08, 07:50 PM
Have you seen the "Root Cause" sticky at the top of this forum? Personally, I wish they had stayed with a cast iron engine, the way God intended them to be made.

ted tcb
11-01-08, 08:38 PM
To 97 Eldo ... what's the newest year Northstar you've seen fail?
Is the 2000 pitch redesign improving the odds?

Also, do you see any evidence of the Bar's supplement tablets doing anything at all?
I know some here (Ranger) have seem them as something to gunk up the purge line of the
reservoir .... think there is any value to the tablets on fixing porous leaks?

Glad to see you're located up here in Ontario ... it gives me the confidence to jump back into the
STS market .... they are such an incredible amount of car for so little money.

97EldoCoupe
11-01-08, 09:44 PM
The tablets do exactly that- plug things up. At least from what I've seen. I don't recommend it. Nor do I recommend any additives to the cooling system. I see nothing but negative impacts.

The thread pitch on the bolts did not change. I have a whack of head bolts. I'll have to look again but the only difference is that the bolts are a 1/2" longer, and the lower bolts on each cylinder bank are deeper in the block. All bolts are the same length. They're still M11x1.5. I've done the HGs on a 2001 DTS two weeks ago. The threads didn't look too bad in the block. The HGs were definitely gone though. Maybe the blocks are a better casting- I know there's more info about the differences here in the forums somewhere, these are just my observations.

My personal forecast for all Northstars- your head gaskets will go. Eventually. Even if it's newer than '00. It's just a matter of time, and how well you maintain your cooling system. And how/where it's driven. Out of the 30+ HG jobs I've done, I've dealt with two 2000's and a 2001 so far. I'm suspecting in about a year or two, I'll be hearing of more 00-03 engines with bad HGs. Right now is the time for '98s and '99s.

The silver lining with the HG dilemma - once the HGs are replaced, you have a great N* again, that you can run as hard as you want (within reason of course). A bad HG isn't the end of your Caddy.

97EldoCoupe
11-01-08, 09:48 PM
Anyone want a big box of old head bolts? I have about 600 old bolts in the trunk of a '96 STS parts car.... free of charge but taker pays the shipping!!


Lol!:D:histeric:

Raze
11-01-08, 11:17 PM
It's cool you're making a kit, but you could already get some pretty nice head studs ready-made, Mark put them on his turbo 99 STS, I want to say they were volvo or something, can't remember now, but I remember talking to him and he said they were great so I'm glad someone's gone ahead with this :)

97EldoCoupe
11-02-08, 08:28 AM
Yeah- and they still needed inserts. Mine eliminate the need for inserts because the studs I make are self contained - larger diameter going into the block. Basically you thread the block, screw the studs into position, and the block is ready for the head gasket and head.

SanDiegoServer
11-03-08, 12:26 AM
Is there anyway to get this job done in the states yet? Preferably near San Diego.

Submariner409
11-03-08, 08:49 AM
97 eldo, Take a look at the Mondello Oldsmobile catalog and the Edelbrock catalog.......they sell packs of different sized hardened head stud washers.

97EldoCoupe
11-03-08, 04:20 PM
There will always be someone working on Northstars, even in San Diego- I just don't know what the prices are in that region. Around southern Ontario I've heard of prices ranging from $3500-$6000 - I guess it depends on how in-depth the repair work is.

Pull your engine or have someone do it. Remove the coolant crossover, exhaust manifolds, accessories, etc.- anything that just adds weight to the shipping. Send the Northstar to me and I'll do all the work on it, install the new gaskets, re-set the chains, etc., for $700 parts and labour included. $1000 if you want the oil seals done as well. Shipping is extra. Once you get it back, just re-install the manifolds, coolant crossover, etc., and you're ready for re-installation. Engine will be returned to you nice and clean with a bill of sale, warranty papers and a placard for your engine bay proving the work.

Chain guides/tensioners/chains /gears will be inspected and if something needs to be replaced that will add to the cost.

Just make sure you have a good engine to start with- all cylinders working, no bearing knock. This may be a good alternative to rebuilt engines for $3000- the Northstars usually don't need rebuilding unless something goes wrong.

Sub- thanks I'll look into that. I have connections for high-alloy washers and nuts, etc.

sofireguy
11-04-08, 10:03 AM
I have talked with Jake and I will be heading his way to have my 4.6 N* worked on soon. I'm pretty excited about having my SLS back on the road.

tateos
11-04-08, 04:37 PM
There will always be someone working on Northstars, even in San Diego- I just don't know what the prices are in that region. Around southern Ontario I've heard of prices ranging from $3500-$6000 - I guess it depends on how in-depth the repair work is.

Pull your engine or have someone do it. Remove the coolant crossover, exhaust manifolds, accessories, etc.- anything that just adds weight to the shipping. Send the Northstar to me and I'll do all the work on it, install the new gaskets, re-set the chains, etc., for $700 parts and labour included. $1000 if you want the oil seals done as well. Shipping is extra. Once you get it back, just re-install the manifolds, coolant crossover, etc., and you're ready for re-installation. Engine will be returned to you nice and clean with a bill of sale, warranty papers and a placard for your engine bay proving the work.

Chain guides/tensioners/chains /gears will be inspected and if something needs to be replaced that will add to the cost.

Just make sure you have a good engine to start with- all cylinders working, no bearing knock. This may be a good alternative to rebuilt engines for $3000- the Northstars usually don't need rebuilding unless something goes wrong.

Sub- thanks I'll look into that. I have connections for high-alloy washers and nuts, etc.

That sounds very fair, and thanks for sharing your process; I know you were reticent, at first, but I hope now you see it can only increase your business, not take anything away.

97EldoCoupe
11-04-08, 06:59 PM
Thank you tateos and sofireGuy!

Hogg
11-06-08, 07:40 PM
Hi Jake. My Father and I spent a few hours this week driving around to local dealerships and machine shops looking for you. (to no avail lol)

We have a 1998 STS that needs your service. We are from Woodstock ON.

Looks like you are onto a good fix.

I have your email and will be in touch.

thanks

peace
Hog

97EldoCoupe
11-07-08, 04:16 PM
Hi Hog, I'm backed up for about 2 1/2 weeks right now, give me a call so I can schedule in your '98 STS. my number is on my site - www.northstarperformance.com

wallace902
11-07-08, 05:23 PM
Hi! Jake,cheers:food-snacking:.wallace.

97EldoCoupe
11-07-08, 10:52 PM
Cheers Wallace! How's your '99 Deville Doing? Wallace's 99 was one of the first cars I've done after a few of my own.

Hogg
11-08-08, 11:40 AM
Hi Hog, I'm backed up for about 2 1/2 weeks right now, give me a call so I can schedule in your '98 STS. my number is on my site - www.northstarperformance.com
Thanx Jake. We have been trying the (519) with no success, all we get is a"Sorry, but the number you dialed is not in service" or a busy signal.

We will try the 877 number, I just spotted it this morning. We'll give that a try and see if that wprks for us.

peace
Hog

97EldoCoupe
11-09-08, 08:57 AM
Hi Hog, my cell phone is down- everyone's "Rogers wireless" phone is down around here. Try 1-877-866-5355 or 519-866-5355. Either one of those should work, if I don't pick up please leave your number- when I'm working I sometimes don't hear the phone over my compressor or air tools. Cell is 519-550-0056 if you want to try again...

-Jake

wallace902
11-09-08, 10:51 AM
Hi! Jake,my 99 deville running fine. no more over heat,thanks for your great help!!!

Hogg
11-11-08, 08:07 PM
No problems Jake, thanks for returning the call. When its our turn, we will be loading the STS up and bringing it down to you.

Thanks again.
peace
Hog

97EldoCoupe
11-13-08, 10:29 PM
Good news, I`ve located a new manufacturer to supply my custom machined studs. This means I get a break from my lathe- I can get back to doing HG repairs. Anyone who wants to repair their Northstar engine without inserts should contact me. They are expensive but their machining equipment is top of the line CNC and they do heat-treating in-house.

I want 5 people who are willing to go the insert-less route and use my studs in their Seville, Eldorado, or Deville. Then I want feedback for my website - the good and bad. And pictures of the installation. Drive your car as hard as you feel like (without causing internal engine damage of course, use common sense) and try WOT as much as you want.

Use approved coolant only- by this I mean what I trust. Prestone brand, Dex-Cool approved coolant, and de-ionized or distilled water. Not GMs Dex crap, or any additives.

For these 5 selected people I will offer 5 years, unlimited mileage warranty against head gasket failure. The price of the kit is $550 canadian dollars including shipping. I`m taking pre-orders now, ready to start shipping December 1st 2008. Should the gaskets fail within 5 years of the shipping date, I will refund the $550 and offer a discounted price on a complete drop-in replacement Northstar.

I believe that this method beats all types of inserts hands-down. Who wants to give Northstar Performance`s SureGrip head stud kit a shot?

Destroyer
11-14-08, 08:05 PM
You really seem to be on to something. Props to you for going where nobody has gone before with the N* and making it so affordable for people that got a lot more than they bargained for buying a N* car. If you had a few locations strategically placed in the USA you would be making a ton of money. At $3500 up to $6k that people are being quoted for this repair, it often exceeds the value of the car itself, but at your prices w/a warranty its a win-win. Good job man!.

Submariner409
11-14-08, 09:19 PM
97EldoCoupe, Am I correct in assuming that, in order to complete a successful head stud modification, the engine must be removed and then reassembled outside the car ?

(Understand that I'm playing devil's advocate here......:devil:)

mythy
11-14-08, 10:40 PM
I noticed headers coming soon on your site.. Have a any info or pics of a prototype?


Oh and yea thread hijack :yup:

97EldoCoupe
11-15-08, 01:07 PM
The engine either has to be removed from the car or you need to drop the subframe. I've never done a HG job in the car, nor would I try it. ESPECIALLY with studs it will not work. You need clearance to slide the head over the studs.

I'm working with someone about setting up some other shops in Canada and the U.S. I have relatives in Texas as well, conveniently with large workshops. I may be able to do some HG jobs in west Texas if they were lined up- anyone willing to make the drive out to Texas, PM me.

The headers is work in progress. No clearance to work with. They're a little ways from complete. That's all I'll say right now. But I'm pretty sure the HP gains are well worth the effort. When the prototype is finished I'll be working with a local manufacturer to mass produce them, if the demand is high enough. My test car will likely be my '98 STS. All I can say right now is the flat crossover pipe will be extremely modified and more than likely, eliminated/relocated. I'm exploring some different options. The Northstar is a high performance machine and it needs an exhaust system to match. I cut one of those X-over pipes in half at the narrowest point to see the opening. There's not a whole lot of area for exhaust to flow.

97EldoCoupe
11-15-08, 01:10 PM
Another thing- there will no longer be a Y-pipe. True-duals front to back. on the 98+Seville and 00+deville, the true duals setup is easy. The older cars and Eldorados is going to be tricky because of the way the intermediate pipe bends around the fuel tank.

ejguillot
11-16-08, 09:10 AM
That sounds good! While my N* is so far trouble free headgasket wise *knocks on wood trim* , I'm interested in the headers (and eventually going full dual exhaust).

ted tcb
11-16-08, 02:14 PM
Well done, 97Eldo.
I posted a thread featuring your Kijijji ad for HG repairs ... I'm glad that you've satifsfied most of the sceptics.
I used to believe that if I kept up on my coolant/tablets, I would likely escape any pulled headbolts on my older STS'.
From reading your reviews of your repairs, it seems like proper maintenance will not change the inevitable.
These HG's will fail, its just a matter of time.
We're fortunate to have your reasonable services up here in Ontario.
Keep up the good work.

97EldoCoupe
11-16-08, 03:24 PM
Thanks Ted! Proper maintenance from day 1 of vehicle ownership could likely prolong the HG repairs for a very long time. That means getting rid of the factory Dex-Cool immediately. Who would buy a new car and have the coolant flushed right away? If only everyone had known ahead of time....

I spoke to Prestone's laboratory. They're convinced that Dex eats the HGs, antough they couldn't tell me they had proof of it. I spoke to Valvoline's Zerex lab technicians. They CONFIRMED that Dex was eating gaskets. From what I've seen, and from speaking to some original owners of a few cars that I've done the HGs on, I could almost swear that Dex is destroying the HGs. The one owner had never used ANYTHING but Dex. Those were among the worst gaskets I've ever seen.

ted tcb
11-16-08, 03:33 PM
So, is GM Dex the culprit with all those intake gasket failures on the 3.1/3.4/3.8L motors?
Or, are those failures simply a result of crappy gasket material?
Also, why aren't the HG's failing on other GM motors ... is it because GM Dex doesn't work well
with aluminum blocks, but is ok on old fashioned iron blocks?
I get easily confused.

Ranger
11-16-08, 09:05 PM
Those are the same thoughts that come to my mind Ted. My wife's '96 Bonneville with 150K still has Dex and has no problems. I don't know what to believe anymore.

Destroyer
11-16-08, 09:16 PM
Thanks Ted! Proper maintenance from day 1 of vehicle ownership could likely prolong the HG repairs for a very long time. That means getting rid of the factory Dex-Cool immediately. Who would buy a new car and have the coolant flushed right away? If only everyone had known ahead of time....

I spoke to Prestone's laboratory. They're convinced that Dex eats the HGs, antough they couldn't tell me they had proof of it. I spoke to Valvoline's Zerex lab technicians. They CONFIRMED that Dex was eating gaskets. From what I've seen, and from speaking to some original owners of a few cars that I've done the HGs on, I could almost swear that Dex is destroying the HGs. The one owner had never used ANYTHING but Dex. Those were among the worst gaskets I've ever seen.My '97 S10 had Dex (4.3) so did many other V8's and they never had the problem. Even if Dex did "eat" the H/G's we are talking about head bolts separating from the block right?.

C0RSA1R
11-16-08, 09:34 PM
This is a great discussion. So far, this thread has been one of the most informative I've seen on here. I'm glad I took the advice of all the folks on the Eldorado/Seville forums and checked out the entire site, because already like four or five questions I was planning to ask have been answered.

97EldoCoupe - that is some impressive work you did on that engine pictured at the start of the thread. I was wondering a few things . . .

First, I just replaced the coolant at the dealership on my 98 ETC 300hp N*. They used the Dex-Cool, put the recommended number of tablets in, etc . . . I also had them do a combustion by product test, both before the replacement, and then after two hours of solid driving punctuated by more than a few WOTs (;)). Both tests came back clear. I know that two hours is probably too soon to make a judgment, but it made me feel better and it was offered free. Question, should I change the coolant again this summer (I'm storing it the moment snow falls here in NY) to get rid of the DexCool? Or should I just leave the DexCool in, and hope that since it will still be pretty new come springtime that a problem is unlikely?

Also, let's assume the worst happens and my HGs go at some point in the future. I'm pretty good with a wrench - but that N* looks pretty intimidating to a newbie. If I could get the car to you in one piece, how much would you charge for the full repair (taking engine out, repairing, putting engine back in), and how long would it take if I had scheduled a job and there was no initial wait? You're not too far from Albany for a drive, and I have friends in Niagara Falls who could help me out with getting my car back from your shop when the work was done.

Crossing my fingers that this remains hypothetical, but I've been in love with Eldo's since 9th grade and I would sell a kidney on Ebay to keep mine alive until Ragnarok comes around. :bighead:

'Cuz then it's just moot. :helpless:

Ranger
11-16-08, 09:45 PM
My '97 S10 had Dex (4.3) so did many other V8's and they never had the problem. Even if Dex did "eat" the H/G's we are talking about head bolts separating from the block right?.
This is the eternal chicken or the egg question. One theory is that the threads fail first due to a casting flaw, the head lifts enough for coolant to leak past. The other theory (the one being discussed here) is that the gaskets fail first, then coolant leaks into the head bolt cavity and electrolysis (steel bolt & aluminum block) begins, eventually corroding the threads and they pull.

C0RSA1R
11-16-08, 10:43 PM
Let me just throw this out there - why couldn't it be both?


This is the eternal chicken or the egg question. One theory is that the threads fail first due to a casting flaw, the head lifts enough for coolant to leak past. The other theory (the one being discussed here) is that the gaskets fail first, then coolant leaks into the head bolt cavity and electrolysis (steel bolt & aluminum block) begins, eventually corroding the threads and they pull.

Perhaps some people do not change their coolant on a regular basis, or put too many tabs in when they do it themselves, or use a crappy Wal-Mart additive in their DexCool, and this leads to longer term corrosive effects on the HG. You know, the coolant gets old, more water or other contaminants leech in somehow, and this breaks down the HGs over time. A little old lady might drive a Caddy for a decade and not change the coolant - then some young buck buys the car up, runs it hard for a while (grinning with glee the whole time), and *Kaboom* - bye-bye HGs (and $3000+). Or the crappy additive increases the corrosion, or has some reaction with the metal of the gaskets, and the same thing happens without having the head lifting at all - at first.

And maybe sometimes, the coolant is fine and dandy, not having any problems with the gasket. Changed every 24 months, no crappy additives, seems kosher at first. Then someone pushes the engine too hard (which would be impressive), or that particular block or set of bolts has a flaw in the material/casting/threads. This results in the head lifting up a little, allowing coolant into the bolt cavity and thus promoting electrolysis thanks to the water content (and probably the DexCool component too).

The same end result, but there seems to be no reason why it couldn't have two failure modes. Perhaps one happens more often (or even the vast majority of the time), but both seem plausible to me. Both would result in coolant getting into the thread cavity in the block, and really the only thing that would be different about the end result of the engine is that in the first case, the HGs would be very corroded but in the second case, it would be the bolt holes in the block that showed the major damage.

Of course, I sort of am that aforementioned "young buck", but I want to see what the more wizened members of the discussion think about this. :worship:

Destroyer
11-16-08, 10:56 PM
...........the gaskets fail first, then coolant leaks into the head bolt cavity and electrolysis (steel bolt & aluminum block) begins, eventually corroding the threads and they pull.
If thats the case how is the '00-up N* improved?. They still use Dex right?. If head gaskets leak first and coolant leaks into the the head bolt cavity causing corrosion in the threads then the problem still exists in '00-up N*'s. No?. Still, Dex has been used in many if not all GM cars for over 10 years now and only a few of the motors have this problem. The Chevy V6 and V8 does not.

Ranger
11-16-08, 11:07 PM
Corsa1r, cooling system maintenance is certainly a factor and ignoring it WILL cause an eventual failure. I am assuming that the maintenance has been kept up with.

Destroyer, 2000+ did have an improvement to the head bolts and many other GM engines don't see the same problem. That is why I tend to lean towards the alloy or casting theory and still use Dex.

ryannel2003
11-16-08, 11:10 PM
I don't see how the 2000+ Northstar was improved that much. Mine blew a HG at 54k miles, and the water crossover was leaking. I believe the pitch for the headbolt was changed slightly, and again in '03. From what I have read on these forums, only 2 or 3 '03 Northstar's have blown a HG.

Ranger
11-16-08, 11:12 PM
The problem was not "solved" in 2000, but was drastically reduced.

ryannel2003
11-16-08, 11:16 PM
Then here's another question:

What about the '93-'95 Northstar, which used regular green coolant? The HG's on those don't have nearly as many problems as the '96-'99 with the Dex-Cool do. I'm sure part of that has to do with the cost of the repair being worth more than the car itself, but at my dealership I've never seen a '93-'95 N* Cadillac in for HG. I've seen 15-20 '96-'99 and maybe 4-5 '00+ models. Some older folks like to hold on to they're cars, so I would have expected at least one.

Ranger
11-16-08, 11:34 PM
Given your age, I'm sure you have not been there too long and I'm sure you have a good point on the value of the cars at this point. No one is going to put that kind of money into a '93 - '95 at this point. I suspect if you where there 10 years ago, you'd probably have seen more '93 - '95's. I seem to recall more of them as well since I have been here (4 years). Ask your service manager or a mechanic that has been there for 10 or more years and let us know what they have to say.

ryannel2003
11-16-08, 11:38 PM
Only 2 years so far. I'm know that you're absolutely right, but could the Dex-Cool have made a bad situation even worse? I know that the interval for green coolant is 2 years, so if you skipped a year or so, well you'd probably be in for a rude awakening.

Ranger
11-16-08, 11:42 PM
Anything is possible, but I still lean towards alloy or casting. I'm no authority, just my feeling with the few facts I know and a little logic thrown in.

Krashed989
11-17-08, 01:41 AM
Then here's another question:

What about the '93-'95 Northstar, which used regular green coolant? The HG's on those don't have nearly as many problems as the '96-'99 with the Dex-Cool do. I'm sure part of that has to do with the cost of the repair being worth more than the car itself, but at my dealership I've never seen a '93-'95 N* Cadillac in for HG. I've seen 15-20 '96-'99 and maybe 4-5 '00+ models. Some older folks like to hold on to they're cars, so I would have expected at least one.

My 94 eldo blew its HG at around 130k miles. I found a guy willing to sell me his (rear ended & totaled) STS for $50. Since my boss has a tow truck, he towed the car to my house for free. So I had that whole powertrain that I could transplant into my car (and I did).... My point is, it was a lot cheaper to do it myself than to bring it to a dealer. I dont trust anyone but me working on my car anyway. Never can really tell what kind of mistakes the mechanic made untill it bites you in the arse.

As for the HG issue... I'm more inclined to think that as long as the engine hasn't overheated (and the coolant is good), the HG wont go. I really think that the expansion of the aluminum vs the expansion of the head bolts was taken into account when the engine was engineered. So as long as the engine remained in its normal operating temp range, it was fine. As soon as you spring a leak and overheat the engine past 250+ degrees F the head expands to the point where the bolts start pulling from the bock. It may not be evident at first, only a minor weakening of the threads in the block, but after a while of driving the threads will only get weaker.

I dunno about the corroded HG's, but I do know that people will try all kinds of cheap crap before paying $3000+ on a major job.

ryannel2003
11-17-08, 08:47 AM
Block sealer seems to be the most popular cheap fix here on the forum. I've heard of people having sucess with it, but the general consensus is that it doesn't work. Simple as that.

It's definitely a fault with the engine, and GM should have caught it before the '96 models hit the dealer lot, and should have fixed the '93-'95 models for free. The '99 model year is hit the worst; I think that if all of those cars had a regular coolant change (maybe every 3-4 years instead of 5), that number would be dramatically less.

97EldoCoupe
11-19-08, 11:39 PM
Dex is a problem. I think a reaction with the aluminum is causing the Dexcool to become corrosive and eat the HGs. You should see my old HG collection. I can show you gaskets used with green coolant, and gaskets used with Dex. BIG DIFFERENCE.

The 2000-03 Northstars used the SAME EXACT THREAD PITCH on the head bolts. The difference is the bolts are longer by about 1/2 an inch. That is the only difference. Same thread length, same thread pitch, same diameter bolt. M11x1.5. The only way the longer bolts can help is possibly with the expansion ratio between steel and aluminum. The blocks may not be as porous. But the head gaskets give out on 2000-03 engines just as well as any other N*. Don't be fooled.

Corsa1R - Yes, I would change that coolant- I wouldn't even let it sit with the Dex in it. Yeah I could be wrong but I just don't trust the dex-cool. Any doubts is enough reason to remove the coolant and switch brands. And I have serious doubts about trusting Dex-cool. "Prestone Dexcool Approved". That's what I'm sticking to. And change/flush it every two years. It can't hurt. And if your HGs do blow, my price is going up a bit because some of my costs went up. The price is $1500 flat, parts, labour, bolts, coolant, oil, filter, everything. The only way I would charge more is if a chain tensioner collapsed, or a new water pump was needed, etc., But when my price went up from $1250, so did my warranty. 2 years or 31,000 miles. It would take me 2-3 days start to finish. You're talking about an Eldo, right? A couple of long days I can have it done if all the bolts come out ok.

97EldoCoupe
11-19-08, 11:44 PM
I called a local GM sevice dept. today to get a quote- just for the hell of it. they told me to do the HGs on my 1998 STS, $4,500.00. And they said it would be extra if the head bolt holes were corroded away, "Then we have to call a guy to come in and tap the block". And oil seals were $800 more for labour, not including parts.

Hey, I know it's underhanded. But I was dying to know what they're actually charging around here! :histeric:

97Concours1
11-24-08, 01:17 AM
I called a local GM sevice dept. today to get a quote- just for the hell of it. they told me to do the HGs on my 1998 STS, $4,500.00. And they said it would be extra if the head bolt holes were corroded away, "Then we have to call a guy to come in and tap the block". And oil seals were $800 more for labour, not including parts.

Hey, I know it's underhanded. But I was dying to know what they're actually charging around here! :histeric:


97EldoCoupe,

And, that's $4,500+ for a questionable Timeserted process that may not hold! Your process is 1/3 the price and by all evidence, a permanant fix.

I did mine with the Norm's inserts and have 10k miles on it - so far so good. I think the Norm's inserts have a pretty good track record so far too. The only possible advantage of Norm's that I can see is it retains the springyness of the original small diameter head bolts. This MAY allow the aluminum heads to expand and contract from temperature with less distortion - MAYBE. Don't get me wrong, if I had to do another one I'd be 100% confident in your process and make the 5 hour drive (with a tow dowly) to have you do it.

I was thinking of a similar idea to yours while I was doing mine. I've been thinking of a single stud repair kit that could be used while the engine is in the vehicle. Pull the valve covers and find the head bolts that are loose. Pull them out, and drill and tap the block to the next size while the engine is still in the car. Then install a custom stud, and torque. I think the gasket around the cylinder would re-seal because I don't think they actually blow out, they just leak do to the lack of clamp force. This, of course, would be a low budget temporary fix for cars that aren't worth investing much money in. It may last 5k miles, 10k miles or not at all, but then the next stop is the bone yard. But then again, at $1,500 you've made it possible to fix it the right way for a reasonable expense. And doing a half-ass job doesn't make sense anymore - never mind.

Great thread. Lots of great info on this issue. And finally a light at the end of the tunnel for many, thanks to your fix.

97EldoCoupe
11-24-08, 04:15 PM
Thanks 97Concours, I know what you mean about the aluminum expansion and steel bolts. The only real solution to that is a spring on the end of the stud that would allow the aluminum to expand and contract while maintaining the same clamping force on the gaskets. But finding a spring or spring washer with that much strength or resistance to compression, would be next to impossible. I'm the kind of guy who's open to impossible ideas so I just might look into something like that yet. I just never trust anything like that to hold a cylinder head down.

I've been thinking a lot about the head bolt design on the Northstar. I very much doubt that the head bolt expands and contracts more than what steel normally does with temperature fluxuation. If the expanding aluminum had enough force to stretch the bolt at high temps, it would not contract when the engine has cooled. It would result in a stretched head bolt. Which could be partially the cause of the HGs failing. The original head bolts are not made from spring-grade steel.

The head gaskets rust away and flake apart. It's not just the bolt problem. It's a combination of both. I know what you mean about installing studs in the car, and I agree - if you're lucky it would last a while longer.

From the expansion/contraction, one of two things will happen. It will crush the gasket, or destroy the threads in the block because aluminum is weaker than steel. I've had both my '97 Eldo and my '98 STS in the red-zone on the temp guage with the new HGs. Fixed the blown hose on the STS and replaced the broken belt on the Eldo, both still 100% normal running temps ever since. This is a chance we take with aluminum engines. Expansion/contraction is inevitable. I believe the head gasket will absorb much of this expansion. But it's very important to keep the cooling systems maintained and to make sure the temp guage doesn't swing too much past 12 o'clock.

Wallace902 (a member here) has the first car that I've done besides my own vehicles- a 1999 Cadillac Deville D'Elegance. He will indeed let us all know if and when his HGs fail, beginning with the guy that did the job. I have a record of 0 failures to date from 44 Northstars including 4 of my own. I hope to keep that 0 failure record for as long as I possibly can.

I know Norm's inserts is a good design too- I just prefer a one-piece solution instead of any kind of insert. One piece of solid machined steel.

97 Concours thanks for the vote of confidence! :thumbsup:

tateos
11-25-08, 07:22 PM
Thanks again for sharing your process, and I don't think you have lost any business by doing that, have you?

ted tcb
11-25-08, 09:14 PM
No, but he has spent a lot of time and invested considerable resources into perfecting the process.

It would be nice to see 97Eldo put the entire process onto protected software, and offer it for sale to specialty shops.
His efforts should be rewarded.

97EldoCoupe
11-25-08, 09:52 PM
Tateos, no problem. No I haven't lost any business but there will always be people who won't approve of my process. I'm keeping track of the results and so far every engine I've done has held up very well. That's why I'm being so careful with every engine I do, I want to keep a perfect track record as long as possible. I just completed a 4.0 - 4.6 swap in an Olds Aurora in about 28 hours flat (without any sleep), head gaskets done on the 4.6 as well in that 28 hours. The owner was in a rush, but is quite happy with the added power!

I found a custom bolt manufacturer to machine and heat-treat all my studs now so I can focus on doing the HG jobs instead of spending hours in front of a lathe. I've asked them to make enough studs for 10 kits, and they should be ready by the end of next week. They're expensive but that's what you get when you go custom... Also their machinery is all CNC - those studs will be accurate and consistent in strength. They do heat treating on site- I toured their facility, it was quite the place.

Ted, thank you again. Maybe I'll do that. Maybe I'll do a 1/2 hour DVD on the entire HG process in addition to making the kits, including the teardown, machine process, and re-assembly. We'll see.

wallace902
11-25-08, 10:34 PM
Hi! Jake, my deville still working perfect.Thanks again!! BTW i shipped out the light today,sorry for the delay!

97EldoCoupe
11-26-08, 08:51 AM
Thanks Wallace- those HIDs are going to be great for my STS. No problems for the delay, I understand. I hope I get a chance to stop by your store before Christmas!

97EldoCoupe
11-29-08, 09:11 AM
I see someone who shall be nameless on ebay (selling inserts) does not like the idea of me selling stud kits. At least my kit includes a very strong drill jig. I don't see anything wrong with using the NS300L kit- in fact the man behind it has a very good idea. I won't sink to the level of insulting someone's work. Not even if money is on the line. People have had positive results with the NS300L kit and people have had positive results with my stud kit. To each his own. My personal opinion is that a one piece stud, being torqued from on top (already in the block, a full 2" of thread holding) is just better. Time will tell.

I have modified my stud kit- same thread length/diameter in the block, 7/16" passing through the head. THIS IS THE SAE EQUIVELANT OF THE FACTORY BOLTS. If the factory bolts stretch as the aluminum heats/expands, and then shrinks again as the engine cools, so will these. My studs will NEVER crack the block and those accusations are false. The reason I changed to 7/16" is so the heads don't have to be re-drilled. This makes installation easier. For my own cars I'll still be using 1/2".

The studs are now fine thread for torquing on top- remember it's still coarse thread in the block. The fine-thread is good for more torque than coarse. They are now custom CNC machined and heat treated at a large fastener manufacturing facility. The only thing I make now on my lathe is the taps and drill jigs. You won't find a more accurate drill jig.

eyekandyboats.inc
11-30-08, 10:04 PM
97 eldo coupe
I just wanted to say Hi, and how awesome it is that someone is taking the initiative to help us who have these issues
your headers sound awesome. and i look forward to one day doing business with you. I come down your way quite often for business!
i have your website bookmarked and phone number down!.
thanks
Taylor-

97EldoCoupe
12-01-08, 12:00 AM
Hi Taylor, thanks! The headers are work in progress but I plan to have the prototype complete by mid Jan and set up for production by June/09 if not a bit sooner. I'll also be dyno testing the engine with the headers installed, maybe a mild port/polish on the heads. A custom intake is next that will utilize the factory throttlebody and accessories. I'm still wondering if any gains can be acheived with a modified/custom intake with a different runner set-up. A nice custom cast-aluminum supercharger would fit nicely between the heads in place of the original intake but that's beyond my capabilities right now. A Eaton M90 would be pretty cool on top of a Northstar, but someone's going to have to be able to hack the PCM before that'l be feasible.

I can see the Northstar has a lot more potential. The stock exhaust is holding the engine back. A lot. I'm predicting a peak HP increase of around 40-50 HP But this is just a rough calculation right now. Throttle response should be improved a slight bit too.

The headers are just the beginning of the "NX8 Performance Package". 3 cars will be prototype/testing cars for the NX8 Package. A black on black 1998 Cadillac Seville STS, a black 1999 Cadillac Deville, and a red 1997 Cadillac Eldorado. All will be heavily modified and receive drivetrain and engine mods, body modifications, custom wheels, and special badging. Once complete, packages will be available for the Deville, Seville, and Eldorado. I'll be working with a body man to design the body kits and custom graphics. I won't release the full details yet but it's going to be a professional conversion job- nothing too radical (they're Cadillacs, not rice burners). Anyone who needs their HG's done, they will be done in the conversion process. This is quite a ways away right now, still on the design tables. But the headers will be available soon.

Oldsmobile Aurora owners, the NX8 package will be available for you too- the best part is, the packages starts with a 4.6 liter conversion....

All NX8 cars will be putting out around 375 horsepower (engine horsepower). Unless I win the lottery and pay Vortech or Paxton to custom design a supercharger kit for Northstar Performance....

C0RSA1R
12-03-08, 02:06 AM
97Eldo, I may just take you up on your offer this summer. Not right away - once my ETC comes out from the cover (she's officially put away for the winter), I'll want to take her for a few thousand miles of cruising. But on the way, I might just save up a few thou' and drive on down Canada way, and see about getting that uberfix done on the heads. Might as well, if I can afford it - probably less expensive than waiting for a problem to happen.

I assume you also do other work, like custom exhaust and the like, so depending on where I'm at when I take some time off work, I'll ask you what sort of work for what price can be done to add some flair to a 98 ETC (not like it really needs it :thumbsup:).

I agree with the fella at the start of this thread: it's nice to see some actual craftsmen are still around to tinker, test, and solve the technical aspects. Esp when one chooses to work on Cadillacs, one of the truly finer things in life.

STSj90
12-03-08, 07:25 PM
Hi Taylor, thanks! The headers are work in progress but I plan to have the prototype complete by mid Jan and set up for production by June/09 if not a bit sooner. I'll also be dyno testing the engine with the headers installed, maybe a mild port/polish on the heads. A custom intake is next that will utilize the factory throttlebody and accessories. I'm still wondering if any gains can be acheived with a modified/custom intake with a different runner set-up. A nice custom cast-aluminum supercharger would fit nicely between the heads in place of the original intake but that's beyond my capabilities right now. A Eaton M90 would be pretty cool on top of a Northstar, but someone's going to have to be able to hack the PCM before that'l be feasible.

I can see the Northstar has a lot more potential. The stock exhaust is holding the engine back. A lot. I'm predicting a peak HP increase of around 40-50 HP But this is just a rough calculation right now. Throttle response should be improved a slight bit too.

The headers are just the beginning of the "NX8 Performance Package". 3 cars will be prototype/testing cars for the NX8 Package. A black on black 1998 Cadillac Seville STS, a black 1999 Cadillac Deville, and a red 1997 Cadillac Eldorado. All will be heavily modified and receive drivetrain and engine mods, body modifications, custom wheels, and special badging. Once complete, packages will be available for the Deville, Seville, and Eldorado. I'll be working with a body man to design the body kits and custom graphics. I won't release the full details yet but it's going to be a professional conversion job- nothing too radical (they're Cadillacs, not rice burners). Anyone who needs their HG's done, they will be done in the conversion process. This is quite a ways away right now, still on the design tables. But the headers will be available soon.

Oldsmobile Aurora owners, the NX8 package will be available for you too- the best part is, the packages starts with a 4.6 liter conversion....

All NX8 cars will be putting out around 375 horsepower (engine horsepower). Unless I win the lottery and pay Vortech or Paxton to custom design a supercharger kit for Northstar Performance....

DAMN, Hurry up man. Glad someone is doing stuff for the N*!!!!!!! :thumbsup::thumbsup::thumbsup:

:)

Cant wait to see some pics and stuff!

97EldoCoupe
12-03-08, 09:37 PM
I'm picking up the black on gray 99 Deville this weekend- NX8003, that will be part of the NX8 series, also picking up NX8004, a black on black '97 Oldsmobile Aurora.

All conversions will be documented on my site when the time comes.

Corsa, I look forward to doing some work on your ETC. I'm not doing much with exhaust right now. I'm in the process of renting a nice big shop- I'll be moving in around the 15th. A hydraulic exhaust tubing bender is already on the shopping list. I can't wait to start working on the NX8 series cars, maybe yours could be one of the future conversions? Wait and see what's on the design tables.

Destroyer
12-03-08, 11:15 PM
I'm picking up the black on gray 99 Deville this weekend- NX8003, that will be part of the NX8 series, also picking up NX8004, a black on black '97 Oldsmobile Aurora.

All conversions will be documented on my site when the time comes.

Corsa, I look forward to doing some work on your ETC. I'm not doing much with exhaust right now. I'm in the process of renting a nice big shop- I'll be moving in around the 15th. A hydraulic exhaust tubing bender is already on the shopping list. I can't wait to start working on the NX8 series cars, maybe yours could be one of the future conversions? Wait and see what's on the design tables.
I'm actually anxious to see this. What is an NX8? Where did that name come from?. Ok, you are trying to be a Steve Saleen or a Jack Roush kinda thing for the N* Caddy's. They are doing it to new cars and you are doing it to old cars with a bad reputation. Dude, its got fail written on it from any and every angle, from a money prospective. You have a real passion for these cars, an abnormal amount. While its a cool thing to watch, financially it will hurt you. Regardless, I still want to see one, I'm sure it will be sweet.

97EldoCoupe
12-04-08, 08:43 AM
I know where you get your name from. All I can do is laugh. We're on a Cadillac forum and all you can do is talk shit about Caddys- I think your time would be better spent on a Ford or Dodge forums, because most of us here love the cars we talk about, even if they do have a few faults. What I do with my time and my money is my business, if I follow through with building a few project cars, or a $2300 set of headers, that's up to me.

Destroyer
12-04-08, 09:44 PM
What I do with my time and my money is my business, if I follow through with building a few project cars, or a $2300 set of headers, that's up to me.Yes it is but you posted it so take the good with the bad. We all would like to see you do it, it would be a great thing to see and it would probably be a kick-ass ride. Now ask how many would actually lay the cash down to buy it................................................ .:shark:

STSj90
12-05-08, 01:31 AM
.......Destroyer is an a$$*ole.................Yep:D




Anyway, Cant wait to see the project up and running man! Would love to see some vids and stuff like that too. Will you be posting up vids or anything when you get to a point in the project?

97EldoCoupe
12-05-08, 06:53 AM
You read my mind.....

Thanks! Oh yeah there'll be videos. I'll soon be posting pics / videos of the rides as they are now. It may be after Christmas- I'm just too busy right now replacing HGs.

Destroyer
12-05-08, 08:42 PM
.......Destroyer is an a$$*ole.................Yep:D





I'm also right:alchi:

ted tcb
12-05-08, 09:09 PM
[quote=STSj90;1701592].......Destroyer is an a$$*ole.................Yep:D



Actually, Destroyer is a real car enthusiast with a gorgeous Mk VIII, and one of the fastest Mustangs you're likely to see.

I appreciate his candor ... he's not afraid to call it as he see's it, even if
its not the official, politically correct party line.

The irony here is that if 97Eldo's services had been available a few years ago, Destroyer would probably still be driving his Northstar powered Deville.

97Eldo is about 3 hours from my house ... his service is the sole reason that I am considering buying a used Northstar powered car again.
Prior to his repair service, every mechanic I spoke with considered the Northstar to be a junk motor ... they would only work on it over protest,
with no guarantee that they had a clue how to fix overheating issues.
You have no idea how refreshing it is to hear someone talk knowledgeably and confidently about our cars.

97EldoCoupe
12-06-08, 11:33 PM
Thank you Ted, :thumbsup:

The Northstar engine is truly a remarkable piece of engineering. Don't ever let the head gasket issue turn you away from purchasing one- just make sure a required HG job lowered the price of the car enough to make it worthwhile, and test the car out before buying. Many owners want $5k for late 90's Caddys even if it has bad HGs. The sad truth is, they're worth $2k at the most with bad HGs, and many of them not even that. New HGs brings the value back up to what it should be and then that's no longer an issue.

Destroyer
12-07-08, 08:47 AM
Thank You as well Ted. You are correct, if 97Eldo or someone with his capabilities and price was around at the time and closer to my neck of the woods, I would have fixed the car. I paid $800 just to get the water pump done cause that's what the mechanic said it was.

97EldoCoupe
12-07-08, 10:02 AM
That mechanic got rich of that water pump job- the pump is around $50-$75 including shipping from RockAuto and the tool is $30 on ebay. 1 hour labour if you're inexperienced, less if you've done it before.

Destroyer
12-07-08, 10:44 AM
That mechanic got rich of that water pump job- the pump is around $50-$75 including shipping from RockAuto and the tool is $30 on ebay. 1 hour labour if you're inexperienced, less if you've done it before.
I know, but it had to be done THAT day cause we needed it. Of course, it still overheated because that wasn't the problem to begin with. He did a few more things for the $800 like change belts and some little things but yeah, I got ripped.

97EldoCoupe
12-07-08, 01:11 PM
Destroyer I don't blame you for hating N*s if you had to go through that. I guess it'd be hard not to. A lot of mechanics don't diagnose the problem correctly- a bad HG on a N* can pass all the compression and coolant leakdown tests because of the bolts pulling up under load.

Sadly, u had a bad experience with your Northstar.

I hope you don't use that mechanic's services anymore. That is WAY overcharging. Some of my customers have encountered the same thing, getting ripped off because it's a Cadillac. So I tell them to come to me if they ever need anything done in the future- it's not always an option but if they're close, it'll save them lots.

N*Fiero
12-07-08, 03:09 PM
Are your studs stress relieved at the block deck? Also, are the 1/2" threads rolled or die cut? I can't tell from the pictures. Thanks.

97EldoCoupe
12-07-08, 06:50 PM
New pics are coming soon. I will check with the machinest who set up the CNC lathe to do my studs this week whether the threads are rolled or cut, but from appearance I would say rolled. The cut quality is WAY too good to be die cut. The shaft diameter is exactly what I asked for, right on 7/16". Rolled threads usually are slightly less diameter, but they may have done two separate machine pocesses for the threaded part and the smooth part. No they are not undercut at the block if that's what you mean by stress relieved. I explored this option before designing the studs, but have my own opinions on undercutting /stress relieving studs. I discussed this with the machinest and explained the application to him and he suggested not to undercut the studs at the block. I will update the pictures soon with the new CNC machined studs. The two diameters are 100% concentric and these are straight. They used their brand new CNC lathe to manufacture these for me.

N*Fiero
12-07-08, 07:36 PM
Thanks, EldoCoupe. On the subject of stress relieved, I meant that the stud was radiused where it changed from 1/2" to 5/8" at the deck. You previously mentioned replacing the seals while the motor was apart. Which seals were you refering to? Appreciate you interest and knowledge. I been there. 20 years twisting wrenches for GM dealerships here in Michigan. Thanks.

Destroyer
12-07-08, 09:08 PM
Destroyer I don't blame you for hating N*s if you had to go through that. I guess it'd be hard not to. A lot of mechanics don't diagnose the problem correctly- a bad HG on a N* can pass all the compression and coolant leakdown tests because of the bolts pulling up under load.

Sadly, u had a bad experience with your Northstar.

I don't hate the N* because of my 1 experience. Really, I don't. It's hanging in here all these years and seeing that my experience wasn't at all uncommon that led to the overall dislike of N* motors. It's the whole package I don't like. Those cars with those motors are bad news because, if for nothing else, the packaging. I've rebuilt motors, I've done many engine swaps and have owned A LOT of cars and my Deville was absolutely the worst when it came to servicing. I've dealt with head gaskets on other cars (very few) and its usually a matter of replacing a head gasket and of course all other gaskets when re-assembling but this crap with timeserts, Norms serts or studs and all plus having to drop the cradle and all that, I wasn't up for it. Money wise, simply not worth it............until you came along but still you would have been too far away. I praised you to high hell for the service you are doing for the N* community. You are an asset to N* owners. AT LEAST I got 10k miles use out of it before it went. Pretty slick with the '05 or '06 STS wheels I had on it. I did quite a few things to it. My wife loved it:

http://i190.photobucket.com/albums/z251/AstrocreepVIII/98Deville1.jpg

http://i190.photobucket.com/albums/z251/AstrocreepVIII/98Deville4.jpg

http://i190.photobucket.com/albums/z251/AstrocreepVIII/98Deville2.jpg


Here is the car that replaced it. Bought this one in '07 with only 16k original miles for $5k and have since added another 17k miles (33k total) and its been fantastic!:

http://i190.photobucket.com/albums/z251/AstrocreepVIII/DSC02427.jpg

AND AFTER A VERY FEW MODS:

http://i190.photobucket.com/albums/z251/AstrocreepVIII/Mark%20VIII/DSC05515.jpg

ryannel2003
12-07-08, 09:58 PM
Damn that Deville was beautiful, the rims really add to the appearance; and though I'm not a fan of Lincoln products, that Mark is absolutely stunning.

Destroyer
12-07-08, 10:39 PM
Damn that Deville was beautiful, the rims really add to the appearance; and though I'm not a fan of Lincoln products, that Mark is absolutely stunning.Thanks man. We (wife and I) truly loved the Deville and I was on my way to making it the car she always wanted........then the head gaskets went. Ok, so I was looking at a $3-$4k repair on top of the $8k I already had into it ($4k for the car plus $4k in mods and repairs). I decided to start looking for another car. Then a '95 Mark VIII came along with 60k miles and I bought it for $3k. Great car and quicker than the '98 that would replace it just 3 months aferwards. Didn't care for the color combo and when the ultra low mileage '98 came along I sold it. Here's a pic of the '95 Mark VIII that initially replaced the Deville (with 18" '06 Mustang wheels I put on):

http://i190.photobucket.com/albums/z251/AstrocreepVIII/Mark%20VIII/DSC02591.jpg

http://i190.photobucket.com/albums/z251/AstrocreepVIII/Mark%20VIII/DSC02588.jpg

http://i190.photobucket.com/albums/z251/AstrocreepVIII/Mark%20VIII/DSC02590.jpg

97EldoCoupe
12-07-08, 10:48 PM
That Deville was a sweet looking ride. I think it would have been worth $3-$4k for the HG job, according to the appearance. What did you manage to sell it for with a bad HG?

Destroyer
12-07-08, 10:57 PM
That Deville was a sweet looking ride. I think it would have been worth $3-$4k for the HG job, according to the appearance. What did you manage to sell it for with a bad HG?Sold it for $1600. Sucks huh?. I had $1200 in the wheels/tires alone!.

ryannel2003
12-07-08, 10:59 PM
I have to say, I'd be furious if the car crapped out on me after doing all that work and getting that little amount for the car.

97EldoCoupe
12-08-08, 04:55 AM
Now see, the HG job would have costed you, say, $3500 at your dealer. You only got $1,600 for it.

I would have spent the $3,500 and driven it for about two-three years. And then while the HGs were still good I would have sold it for around $3-$5k- if it was still in the condition that is appears to be in the pics, you would have gotten that, even three years down the road. You would have recovered your money from the HG job and gotten a few years use out of it. It already had a new $800 water pump job in it, so you lost that too. So you'd have another few grand sitting in the car for a while, so what. Get it back when it sells.

Destroyer
12-08-08, 07:32 AM
I would have done it for the $1200 you charge but not another $3500. Around here a '98 Deville will not fetch anywhere near $5k. I'm finding '00+ models for less than $5k. I saw the N* repair fail too many times and I wasn't taking that chance. I needed another car quick, bought the '95 Mark just hours after realizing the Deville needed an H/G job.

davz
12-09-08, 08:55 AM
Destroyer, Those Marks are badazz.

Good choice. The 4.6l Ford engine is far superior to the N* in the durability dept. I have had 2 stangs with the 4.6 and they are great motors.

I like my sts. Especially now with the Canadian motor (from 97Eldo), but I don't know if I'll have another one. Too bad about your Deville. It looks like a sweet car.

I bought an engine from Jake, and it was worht the 4 hour ride. He really knows his Northstars.

97EldoCoupe
12-11-08, 11:09 PM
Here's a pic of a '98 STS's engine I've been working on. Factory DEX-COOL in the engine it's whole life, 70,000miles on it. Worst HG's I've ever seen.:helpless:

http://www.northstarperformance.com/img/98stsblock.jpg

97EldoCoupe
12-11-08, 11:23 PM
Here's the same engine a couple hours later with the new resdesigned, CNC machined SG102 stud kit installed. The studs are still 5/8" UNC in the block but are 7/16" coming out of the block with fine thread on top. These studs have been tested to withstand 80+ ft. lbs of torque and they stand up to it well. These are springy too like the stock head bolts. Tested in a vice- you twist the stud, it twists right back. There is nothing short of a dynamite blast in the cylinder that will pull these studs out of the engine block.

http://www.northstarperformance.com/img/studs4.jpg

When my price went up to $1500 CAD for a HG job, the warranty went up to 2 years or 31,000 miles (50,000kms). The increase price is because of the CNC studs- they cost more, but the quality is higher as well- so the warranty increased accordingly.

For anyone in the USA, $1500 is around $1300 US dollars right now.

Anyone who's doing the HG job themselves can buy the stud kit from me for $549 US, including shipping. This is slightly more expensive than inserts, but probably 10 times more durable and so much safer for the block. Gaskets are about $45 US for a pair from RockAuto (Fel-Pro) and you won't need to buy head bolts with the stud kit. The kit includes a drilling jig and tap block to ensure the studs go in straight.

It's more cost effective if you're near London Ontario for me to do the entire job because I'm set up for it- I've been doing two cars per week for a while. I've had a customer drive 9 hours from New Jersey to get his HG's done- 6 from the USA so far. I welcome HG jobs from all american Cadillac owners as well as Canadians.

ted tcb
12-12-08, 11:01 AM
Man, I'd love to see the miles one of your "improved" Northstars could rack up.
It's long been said that the bottom end of these motors are very durable ...
with the stud kit in place, these engines should outlive the rest of the car.

xPosTech
12-19-08, 09:05 AM
97Eldo you mentioned a possible Texas tech installing your stud kits. Has anything moved forward on that?

I just acquired a 2001 ESC with 36,000 miles. I haven't had/done an exhaust gas/coolant test yet but I will ASAP. It's a general consensus here that I'm driving a time bomb?

I don't know where London, Ont. is ( I'll check a map) but it might be closer for me to drive to your shop than far west Texas. :rolleyes:

Ted

97EldoCoupe
12-19-08, 09:51 AM
Provided that I get a few cars lined up in Texas in need of HGs, there's a good possibility that I myself will be out there doing a few cars in 2009. No idea exactly when though.

C0RSA1R
12-21-08, 09:53 PM
For anyone in the USA, $1500 is around $1300 US dollars right now.

Wow - ever since I finished my Christmas shopping I've been starting to save some cash here and there (helps now that the Eldo's garaged and covered for the snowy times), thinking about getting one of your HG jobs done sometime in late Summer or early Autumn. Something was bugging me every time I would think about it - not that the price is high, but that I was forgetting something important :hmm:. Bingo, that was it!

I'll still be saving up much more than that, because of some minor travel costs and expenses, etc. Plus, given the way all the markets are these days, who knows there the two currencies will be come summertime. I figure it's a worthwhile investment either way - since I love my car and wouldn't want to have anything but quality work done on her, I'm happy to pay good money for a good job.
:thumbsup:

97EldoCoupe
12-22-08, 05:12 AM
Corsa, I'll be happy to do the HG jobs on your Eldo. Always looking forward to doing the HGs on a car from the USA, less salt on the roads, and yours is garaged for the winter, which means the exhaust bolts won't be rusted in place! They're in a hard to reach place as it is, some of these Canadian cars are a PITA because the bolts are snapping upon removal- usually 97 and down. Nothing quite like working underneath a well-kept car!:thumbsup:

William Miller
12-23-08, 08:55 AM
I'm intrested in your kit for my '98 STS.
I didn't see a way to e-mail you from your site.
I tried to send PM but I don't have the credentials yet.

I'd like to give you some background on my project and ask some questions.
Thanks!

97EldoCoupe
12-23-08, 09:10 AM
Email: jwiebe@northstarperformance.com

No problem, it will be the 2nd or 3rd of January when I get another shipment of studs in. Hope that doesn't ruin any of your holiday plans...

William Miller
12-23-08, 07:40 PM
Thanks for your e-mail address. I sent you some details. I hope to have something started by then, but lots of distractions this time of year!

Thanks again!

ibm4mad
12-23-08, 08:47 PM
Just a side question here, I see that 97Eldo is advocating the Prestone Dex-Cool approved coolant (orange). Would you need to do anything special to switch over to this coolant from GM Dexool? I know that switching from DexCool to green is a no-no without some special steps, because of the chemical differences in the two.

Submariner409
12-23-08, 08:58 PM
I believe that, in addition to Havoline DEXCOOL equivalent, the Prestone version is also approved by GM. Its the same formula, so is not like a "green to orange" change.

ibm4mad
12-24-08, 01:23 PM
If the Prestone and Havoline fluids are approved by GM, then what is different about them that makes them less corrosion-prone than the actual GM dexcool?

Ranger
12-24-08, 02:24 PM
Texico/Havolin IS the GM Dex-Cool.

97EldoCoupe
12-24-08, 03:44 PM
I contacted Prestone's laboratory. They told me their formula is not corrosive, and will not eat head gaskets. They would not completely admit that the factory Dex eats HGs because they didn't want to say anything that could be used in court against them. But they did beat around the bush and hint that it does eat HGs. I trust the Prestone brand. That's all I'll use.

68Futura
12-29-08, 01:49 AM
97Eldo, I'm new here, another proud n* owner! I've been reading through this thread with great interest. I dont have the dreaded hg issue yet, but with 92k miles I'm sure I will soon. I'm considering purchasing your stud kit, but am experienced enough to do the work myself. What do you use or recommend for head gaskets as far as brand goes? I've seen good prices on ERISTIC hg's, but I dont know if some are better than others... Any input will be greatly appreciated!

97EldoCoupe
12-29-08, 10:04 PM
Personally I use Fel-Pro. I always use Fel-Pro, always have, and always will. It's sort of like "when you find something that works, don't go changing things". Every HG job I've done has lasted. Be it on a 403 Olds V8, numerous small block Chevys, 3.8 liter Fords, to name a few, and the 40+ Northstars I've done. Always went with Fel-Pro. I know Federal Mogul (Fel-Pro's is a subsidiary of Federal Mogul) is a big company with a good reputation. They've put a lot of research into sealing technology. They know what they're doing.

What pisses me off is that I still have to pay retail prices. I contacted Federal Mogul about setting up an account, and they won't offer discounts unless you buy over a hundred grand worth of gaskets / parts per year. RockAuto does so much business with me I've got a refrigerator covered in their collector car magnets. RockAuto is a good company to deal with. Just make sure your head gaskets don't have creases in them or bends. I've got a few that I still have to send back to them. Could be an issue with their shipping dept.

68Futura
01-07-09, 09:29 PM
[QUOTE=97EldoCoupe;1671957]That's believe it or not 5/8" UNC in the block and 1/2" UNC coming out of the block. QUOTE]



Now why did you go with 1/2"-13 UNC rather than 1/2"-20 UNF? I would have thought the coarse thread would have less strength, and throw off the torque specs more than fine thread would... and if your torqueing them to around 80 ft.lbs., you must be using something like a grade 6 or 7 right? From what I understand, grade 5 is not strong enough, and 8 is to hard.

97EldoCoupe
01-07-09, 11:24 PM
The stud kit has been revised now. They are fine-thread and heat treated to grade 8 specifications. Grade 8 is not too hard. I've done a lot of testing and this is the correct heat treat for the application. They are not 1/2" either anymore. If you look carefully through this thread you will find the current specs. I have done numerous strength tests, hardness tests, stretch & twist tests, and the failure rate speaks for itself. No failures to date on 50 completed engines.

You are correct that fine thread provides more accurate torquing, and fine-thread also can handle more torque. The two diameters share the exact same concentricity and they are straight. You won't find any bent ones or any that are out-of-line. They're made on a CNC operated lathe and heat treated/hardness tested. They're expensive but well worth it- these aren't honda engines we're working on, these are Cadillac Northstars.

Ur7x
01-12-09, 01:14 AM
Are both ends "fine" thread? Coarse thread is much preferred on the block ends... GM switched to LS1 coarse thread bolts in 2004 and the number of headgasket failures has dropped to zilch... One of the problems with the early northstar head bolts are the fine threads.

97EldoCoupe
01-12-09, 06:31 AM
The block end is coarse thread, 5/8 UNC (11 TPI) and the other end is fine-thread.

I just placed an order for a quantity of CNC plasma cut drill/tap jigs, should be in stock soon.

ToMuchWork
10-10-09, 06:41 PM
I am new to this site and first want to say thanks for all the great info.
I am getting ready to repair a 97 STS 4.6 N* with the dreaded damaged head bolt threads. Just wondering why this thread has stopped? I see no new updates in the last 10 months or so. I was hopping to see the replies of people that had used the studs and their results.

Submariner409
10-10-09, 07:39 PM
The info has moved to extended discussions in other threads in Northstar Performance. So far the studs are the cat's meow followed by a well-done insert job.

ToMuchWork
10-10-09, 11:04 PM
Thanks for the info submariner409. Any thread in particular?
One question I have is when drilling out the block will a good hand drill with a guide work or do you have to use a drill press of some sort?
Thx,

Submariner409
10-11-09, 08:35 AM
The Northstar Performance stud kits come with drills, taps, drill stops (or stepped drills.....), and a drilling jig block. Take a look at the website www.northstarperformance.com

You need to drop the engine, transmission and cradle out the bottom (basically you lower the entire drivetrain, axles and all), seal everything up with tape and plastic (chips fly everywhere), and use a good 1/2" variable speed drill for the job.

Search using the button up in the blue bar ^^^ or begin Googling something like "cadillac forums northstar head gasket repair".

97EldoCoupe
10-11-09, 06:59 PM
We've had really good feedback on the stud kits.

0 stud failures. 1 HG failure that was actually 75% my fault, which we fixed again at our expense. This failure was not stud related at all- the studs still held torque perfectly.

I'm going to estimate that about 175 Northstars are on the road with our studs. Many have been installed by Caddy dealerships, former Caddy techs, and other repair shops. Many by individuals who have done the job themselves. We've had quite a few reports saying it was easier and quicker to install the studs than inserts. We have one INNRS member shop on our list near Chicago, who continues to order and install studs. Many more shops will be added to the list soon.

I'm still trying to convince some, but everyone who has used the studs swear by them and would not go back to inserts.

Ranger
10-11-09, 07:13 PM
We have one INNRS member shop on our list near Chicago
Who might that be Jake and is this list available?

97EldoCoupe
10-11-09, 07:24 PM
http://www.northstarperformance.com/innrs.php

These pages are not complete and are work in progress. The shop's name is Wick Automotive and it's in Rockford, Illinois. The owner is a former Cadillac Technician.

Ranger
10-11-09, 07:25 PM
Ahh. Not far from me. Hope I never need them.

97EldoCoupe
10-11-09, 09:28 PM
I hope not either Ranger, but it's nice to know someone is available nearby just in case. I earn my living from blown HGs but I don't wish it on anyone.

Ranger
10-11-09, 09:38 PM
Just out of curiosity, any idea what they charge?

Destroyer
10-11-09, 09:53 PM
I earn my living from blown HGs.
That explains the love for N*'s.;)

97EldoCoupe
10-11-09, 10:14 PM
I'm going to have to go through my records when I get back to the office but I recall a number around $3300. Somewhere along those lines.

Destroyer how many people love what they do 12-16 hours per day? LOL

The engines are so well designed you just can't help but appreciate how well they do their job- and how efficiently. And how you can blow a lot of cars away with a bone stock 4000 lb car and pass a few gas stations too....

ToMuchWork
10-12-09, 01:43 PM
Block is sitting in my garage waiting for inserts or studs.
I think I am going to go with the studs.

I did send a question to info@northstarperformance.com but have not seen a reply yet. I am sure they are busy working on motors and not repling to emails which I totally understand.

So I will throw it out to the audience here and get some opinions.

My HG's did not blow, had loose bolts causing compression leaks.
Question is " what are the chances that my heads are good and can be reused without taking them to a machine shop and having them checked out"?

They check out to be straight and the valves look good but the shop I take my stuff to wants to charge $500 do do the pair. They will only accept looking at them if they can do the complete job. I do understand their position on this but I really dont want to spend the $500 if at all possible.

So what seems to be the history of the heads when taken off ?

tateos
10-12-09, 07:05 PM
History tell us they will be fine.

I did nothing but de-carbon the combustion chambers with a pneumatic die grinder and a steel wire wheel; the wire wheel took off the carbon buildup, but did not seem to scratch the aluminum in the combustion chambers even a little bit. Then I cleaned out the spark plug threads and sprayed down the top (cam) side with liberal application of WD-40, followed up with compressed air. Finally, I lubed all the cams and lifters with cam lube. That was it.

If memory serves, I'm pretty sure I used the same wire wheel to clean off the top of the pistons, and again, the carbon came right off, but with no damage to the aluminum; the original machining marks on the piston crowns were clearly visible. That wire wheel was steel, but it must have been dull. WD-40 and compressed air completed the process.

Submariner409
10-12-09, 07:24 PM
I'm with tateos. Northstar heads are tough - a good cleaning and lube should be all you need. Even the valve stem seals are seldom a problem. Get to Edelbrock, Mondello (www.mondellotwister.com), or Comp Cams and lay in a tube or two of cam breakin lube, for both the cams/followers and the timing chain tensioners and slippers. (You had better read up on those puppies..........and how to time the cams and intermediate sprocket)

ToMuchWork
10-12-09, 07:53 PM
Thanks again for the info. So the recommendation is to take all the valves out and clean them up real good and lube the cam journals and re-assemble. I can do this but was actually thinking of just removing the carbon from the chambers and ports and any other place I can reach and put them back on. I guess I really should take the time to do it completely but I am really pressed for time. I have read up on timing this motor. I believe I know what to do but I am sure it is going to be a job. Actually I am looking forward to that part as it will mean ,studs are in, heads are on, motors going back together :)

Thx,

ToMuchWork
10-12-09, 08:23 PM
Just one other question. What is the best way to clean the block/head surfaces? I have never cleaned a aluminum block, only iron blocks and really didnt have any problems using a metal scraper which I suspect wouldnt be good to use on the aluminum block. I was thinking of using a hard plastic scraper with a gasket remover solvent.

Ranger
10-12-09, 08:56 PM
You should not need to disassemble the head.

Whatever you do, DO NOT use Scotchbrite. :tisk:
http://www.cadillacforums.com/forums/cadillac-tech-tips/27507-scotchbrite-never.html

Submariner409
10-12-09, 08:59 PM
DO NOT pull the valves, springs, retainers or seals. Leave them alone. Use tateos' rotary wire brush method (not a wire wheel - a wire bundle in a drill chuck) to clean the combustion chambers and (turn the crank) piston tops. Blow everything with compressed air and be careful - you're working with aluminum. Use cam breakin lube on the cam lobes and cam followers as well as the chain tensioners and slippers.

Permatex makes a gasket remover solvent. Try that first.

This was all posted just a post or two back ?????????? Go back and read everything in this thread again. Everything.

tateos
10-13-09, 12:34 PM
DO NOT pull the valves, springs, retainers or seals. Leave them alone. Use tateos' rotary wire brush method (not a wire wheel - a wire bundle in a drill chuck) to clean the combustion chambers and (turn the crank) piston tops. Blow everything with compressed air and be careful - you're working with aluminum. Use cam breakin lube on the cam lobes and cam followers as well as the chain tensioners and slippers.

Permatex makes a gasket remover solvent. Try that first.

This was all posted just a post or two back ?????????? Go back and read everything in this thread again. Everything.

Right - leave everything assembled. I cleaned out the combustion chambers, but even that is optional. Also, just to clarify, I used WD 40 as a flush, not a lubricant. You will end up with a lot of grit everywhere after cleaning out the combustion chambers - the WD-40, followed by compressed air will help carry it away; just keep spraying until it flows clear. The only lubricant was the cam break in lube others and I have mentioned.

ToMuchWork
10-14-09, 03:49 PM
Thanks to all for all the info. I really didnt want to remove the valves so glad I do not have too. I will be ordering the studs this weekend and going from there. I am having a problem uploading pics or I would send a few. I am going to be reloading the OS on my PC so that should take care of that and will send some in the future. Nothing really to see that I am sure most everyone has not already seen other then the mouse nest I found under the intake.

Submariner409
10-14-09, 05:11 PM
:highfive: Your mouse nest is common. Wait 'till you find a six foot black snake................

I made a folder in "My files" called "email resizes". When I run across a diagram or picture with a large file size I email it to myself, using the "Make my pictures smaller" (file, not pic itself) option, "save as" from the email to the folder, and use that to browse for the attachment uploads in here......

97EldoCoupe
10-15-09, 09:58 PM
Never seen a snake yet Sub...lol.....but I've seen everything from mice nests, dead mice, maple keys and leaves, acorns, nuts, a dead bird, feathers, oil, power steering fluid, water, extra nuts and bolts people have lost............and the occasional starter :bonkers:

Joshua412
10-18-09, 04:57 AM
add 1 mouse nest to the list.

ive got 2 northstars sitting in the driveway...

one in pieces.
one waiting to drop in.
wonder if there is a nest under the next one...
how do they get there?

Submariner409
10-18-09, 11:32 AM
Can you see down into the valley/starter motor area just next to the lower front of the throttlebody ?

chacenbra
10-20-09, 06:29 PM
Just one other question. What is the best way to clean the block/head surfaces? I have never cleaned a aluminum block, only iron blocks and really didnt have any problems using a metal scraper which I suspect wouldnt be good to use on the aluminum block. I was thinking of using a hard plastic scraper with a gasket remover solvent.

When I had my motor open I used oven cleaner to deal with the carbon in the cylinders as well as on the heads, worked like a charm :thumbsup:

32vmonte
10-23-09, 01:32 AM
You should not need to disassemble the head.

Whatever you do, DO NOT use Scotchbrite. :tisk:
http://www.cadillacforums.com/forums/cadillac-tech-tips/27507-scotchbrite-never.html

I read something in there about not using steel wool on anything. I happened to use it on my crank in areas where there was a little rust. This is what the machine shop recommended.

Hope that was ok. I know the slight almost not visible rust needed to be gone from my rear main seal area and on a few main bearing journals.

I used WD along with the finest steel wool I could find. Then sprayed the crank and passages with WD. After that I used parts cleaner on it followed by lots of compressed air.

Submariner409
10-23-09, 08:15 AM
The time-honored method of polishing crank journals and machined surfaces is with a strip of crocus cloth followed by a complete rinse with Varsol (mineral spirits).

Steel wool should be OK if you're fanatic about cleanup: steel wool flexes and breaks and leaves thousands of tiny steel "chips" in and on anything it touches. One reason you never use it to prep for a paint job on a boat or light-colored porous outdoor work : the tiny steel chips stay on/in the wood grain and if exposed to weather, water penetrates the paint film and you wind up with rust weeping everywhere. Better to use bronze wool.

97EldoCoupe
10-24-09, 06:40 PM
One of my customers just came back for an O2 sensor replacement and new plugs. 113,000 kms (70,000 miles) on the studs and still going strong. He's an insurance salesman and on the road ALL the time. It will be a year in September since his HGs were done by me.

ToMuchWork
10-28-09, 08:29 PM
Well its been awhile since I posted and was hoping to have a update and maybe some pics but I have not received my studs yet , "bummer" its been 8 days since I ordered them. I sure hope they come soon! Jake, any idea when they may arrive?

jamal newby
01-26-12, 09:07 AM
Hello sir ,.Does engine have to be out of the car?

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where do I order studs sir?

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Hello sir ,Does engine have to be out of car?also where do i order studs??

Submariner409
01-26-12, 09:09 AM
Engine out of the car. Several hours of machine and drilling work.

www.northstarperformance.com (http://www.northstarperformance.com)

Find threads started by and posted in by 97EldoCoupe - click on his username and use the "find threads" tab.

97EldoCoupe
01-26-12, 10:47 AM
Hi Jamal, please email me - info@northstarperformance.com - I would very much like to sell you a set of studs but today and tomorrow I'm catching up on past orders first. Right now constructing a new jig to build the fixture plates (again) because the jigs do wear, and I want to keep everything dead-on accurate.

Next week I should be available by phone full time again.

Thank you