: cometic, felpro or gm oem! Head gasket survey.



mikelawson
04-17-08, 05:19 PM
Looking for some advice on which head gaskets to purchase for my N* repair. I plan on keeping this car for a while so I want the best, not just the most expensive. I like the idea of the MLS gasket, but can only find them from cometic. I've read both good and bad, so I thought I would ask the experts here. I am one of the few to do this in the car vs pulling the engine so if anyone wants pics let me know. I am using norms inserts vs time serts since he was nice enough to modify the drill bit so it would fit in a 3/8" chuck for my 90 degree drill. Thanks for any input offered. Mike.

ejguillot
04-17-08, 06:00 PM
Do a search! :) Quick answer: Cometic apparently has a well deserved reputation for being the best.

tateos
04-17-08, 06:08 PM
I used FelPro - no problems so far

Submariner409
04-17-08, 06:16 PM
Normally aspirated: FelPro or GM. Different car, different engine work, supercharged, Cometic.

tateos
04-17-08, 07:03 PM
I read an article in HOT ROD magazine that the Northstar V-8 SC 4.4L Engine (LC3) has MLS head gaskets - I wonder if they can be used on other N* engines?

mikelawson
04-17-08, 10:17 PM
The cometic gaskets are mls, but I read on some honda(:nono:) forums they had trouble getting an initial seal. The last thing I want is that. I'd like to hear from more people who have repaired these and what gaskets they chose to use.

IXSLR8
04-18-08, 12:39 AM
I decided to go with the Cometic gaskets. I ordered them and got them 2 weeks later. They look like decent quality similar to other stuff I've seen and used on VW diesel 1.9TD's. I couldn't find any other brands making metal gaskets for the 1996-99 N*. That's probably because Allen told me that the headgaskets were developed by Cadillac Hotrod Fabricators with Cometic for his high HP applications in California.

I have Norms inserts and have the block all drilled and tapped. I have ARP head studs for a VW 16 valve that I am using to strap the heads on. Just got my heads back from the machine shop all redone just in case.

Now I'm recovering from all the money I've spent and the looks I'm getting from my wife from doing that! It might be go back to work double time! LOL!

I'm planning to have it all back together by this coming Monday. I'll also be using Hylomar gasket material on the block side of the gaskets as my head side is beautiful and has a new baby smooth mating surface. The block mating surface is not so pretty though the aluminum is good.

mikelawson
04-18-08, 09:46 AM
Sounds like what I was planning. Where did you order your gaskets from? Where did you find the coolant crossover gaskets gmpd? I'll be installing norms inserts this weekend. Did you have any problems with them or was it straightforward? Are you replacing the intake and exhaust manifold gaskets or reusing the old ones? Mine look fine but will probably replace.
Mike

RICOMRD
04-18-08, 09:04 PM
I used Fel-pro and Time Serted, also did mine in car. I ordered the gasket kit from Rock Auto.

If was to do this project again, I would time the cams before I would install the heads, on the work bench and mark the position so I could see the marking from above, and made sure piston # 1 was at TDC before installing the heads. I found it very difficult to time the rear cams in with the heads installed in the car.

mikelawson
04-19-08, 10:20 PM
Before I disassembled I put the engine TDC on cylinder 1. I also used touch-up paint and marked the chain and cams so I could align it all when I put it back together. I drilled and inserted a few holes today. How hard was it to drill the rear holes with the engine in the car. I know everyone says to pull it, but so far it's been only moderately difficult. Does the coolant crossover gaskets come with the fel-pro head set? For anyone interested, Norms inserts are the way to go. I couldn't imagine these would ever pull out of the block. Mike.

IXSLR8
04-19-08, 10:31 PM
Mike,

I got the metal gaskets from cometic: http://www.cometic.com.

I got the coolant crossover gaskets(Felpro brand) from my local autoparts supplier.

I've found that Norms inserts work great and its very strait forward but you have to be very careful drilling. Because you don't have a jig to make everything square for drilling with his bits. I found that predrilling with a 1/2 inch bit before you use his special bit makes it more error free and easier to make it more accurate. I found that the beginning of my head bolt holes in my 96 N* were not the same circumference at the surface as they were 3/8 of an inch below it. The hole was tapered and larger at the top. Just be careful not to go too deep with the 1/2 inch bit. I you do that, I found it easier to drill spot on by predrilling.

Using new intake gaskets and reusing the exhast gaskets.

-dave

Thomas Carey
04-20-08, 10:31 AM
I would go with the OE or FelPro based on my expierence working in my uncles auto shop and my own cars when I was a few years younger. Most of the time I prefer OE gaskets.

Best Regards,

Thomas Carey
Thomas Carey

IMSAnorthstar
04-22-08, 01:48 PM
Mike,

I got the metal gaskets from cometic: http://www.cometic.com.

I got the coolant crossover gaskets(Felpro brand) from my local autoparts supplier.

I've found that Norms inserts work great and its very strait forward but you have to be very careful drilling. Because you don't have a jig to make everything square for drilling with his bits. I found that predrilling with a 1/2 inch bit before you use his special bit makes it more error free and easier to make it more accurate. I found that the beginning of my head bolt holes in my 96 N* were not the same circumference at the surface as they were 3/8 of an inch below it. The hole was tapered and larger at the top. Just be careful not to go too deep with the 1/2 inch bit. I you do that, I found it easier to drill spot on by predrilling.

Using new intake gaskets and reusing the exhast gaskets.

-dave

I agree. Norms inserts are a great product.... except for the lack of a drill jig. I modified the tapping jig, which he supplies, to double as a drill jig. I also added a piece of angle iron to the side and drilled it so you can bolt it down to an adjacent head bolt hole for stability. workes very well now.
http://pic80.picturetrail.com/VOL827/1543635/18343004/310895933.jpg

I

IXSLR8
04-23-08, 10:18 PM
OK, got the Cometic gaskets and my heads all studded, torqued and timed. Nothing pulled out using Norms inserts and ARP studs at 70 ft. lbs.

It will be interesting to see how they work with the exposure to the antifreeze over time and to see how the Cometic gaskets seal over the long term. I used Hylomar gasket sealer on both sides so that should help too. I hope it lasts for a long time after throwing all that money at the block.

tateos
04-24-08, 06:58 PM
I agree. Norms inserts are a great product.... except for the lack of a drill jig. I modified the tapping jig, which he supplies, to double as a drill jig. I also added a piece of angle iron to the side and drilled it so you can bolt it down to an adjacent head bolt hole for stability. workes very well now.
http://pic80.picturetrail.com/VOL827/1543635/18343004/310895933.jpg

I

I like that idea - I thought of it after I was done, but sure - why doesn't Norm just drill two different size holes in the tap block?

RickyHenry
04-25-08, 03:43 AM
Looking for some advice on which head gaskets to purchase for my N* repair. I plan on keeping this car for a while so I want the best, not just the most expensive. I like the idea of the MLS gasket, but can only find them from cometic. I've read both good and bad, so I thought I would ask the experts here. I am one of the few to do this in the car vs pulling the engine so if anyone wants pics let me know. I am using norms inserts vs time serts since he was nice enough to modify the drill bit so it would fit in a 3/8" chuck for my 90 degree drill. Thanks for any input offered. Mike.

I think that from what I've read, using Norms inserts, there is less of a chance of the head gasket failing. If that is the case, why spend $250 on MLS gaskets when you can just go with the OEM? I chose the OEM and I based my decision on believing that the head bolts were the root cause of the blown gasket. This is not a sure thing and time will tell if they last.

RickyHenry
04-25-08, 03:45 AM
I agree. Norms inserts are a great product.... except for the lack of a drill jig. I modified the tapping jig, which he supplies, to double as a drill jig. I also added a piece of angle iron to the side and drilled it so you can bolt it down to an adjacent head bolt hole for stability. workes very well now.
http://pic80.picturetrail.com/VOL827/1543635/18343004/310895933.jpg

I


wish I would have thought of that!!! Maybe Norm can modify his set like you did this. Would have been REALLY NICE TO HAVE THAT JIG!

IMSAnorthstar
04-25-08, 04:17 PM
Thanks guys. I'll have to e-mail Norm with a link to this thread. maybe he'll concider similar changes to his tap jig.
I've been in my shop today, finishing putting together the engine pictured with the jig. I pulled the heads off another engine I had for this one. I had used GM head gaskets to build that motor, but for this one I'm using Felpro, which I won on E-bay a wile back. guess what...... they are the SAME gasket. numbers at the ends, small markings here and there.... I have no doubt that the GM gaskets I pulled off the other motor were made by Felpro. so perhaps there are only two main choices when it comes to head gasket brand. :bigroll:

IMSA

99_concours
05-02-08, 02:30 PM
IMSAnorthstar: You wouldn't mind sharing your adaptation of the jig would you? Or possibly selling or renting it? I am needing to timesert my '99 Concours and am most concerned about drilling and tapping the block correctly and squarely. I will probably not begin the job for another month as I empty out the garage of other car projects but I do want to get it started soon. Got to get one of the Pontiacs rolling again. Broken waterpump bolts in the timing cover...ugh! 70K mile '75 GrandVille Brougham convertible (one of two). Once I get that out of the garage and then re-arange the whole place to get the Cadillac in...

mikelawson
05-02-08, 11:55 PM
I agree about the drilling jig. I have almost finished drilling the holes on my N* and will have the Norms kit up for sale. After I noticed one of my holes were slightly off center, I drilled a second pilot hole as well. It's defiantely the way to go if you're going to use Norms kit. Anyone want to offer an opinion on whether or not my repair is doomed from the hole being slightly off? I know the head bolts give a little, so I feel pretty confident that as long as I can get them torqued properly, I should be home free. If anyone is interested I will be selling the Norms kit for 1/2 of what I paid new (175). Let me know if anyone is interested.

Mike.

Tigman
08-16-08, 11:14 AM
Whats the part number for the ARP Stud kit for the Northstar?

Thanks

Mark

mtflight
11-01-11, 04:10 PM
This is a couple of years old thread, however after seeing the affected head gaskets it is my personal conclusion that they are rotting out due to corrosion. Regardless of the head bolt issue, there is something about the coolant that does not work well with the OEM gaskets over time. MLS takes my vote 100%.

IXSLR8
11-02-11, 03:48 AM
The gaskets just can't handle the coolant part of the block over time.

I'm currently doing another 1996 block right now with my son and with more of Norms inserts, more studs (ARP 204-4204: 2qty needed) and another set of Cometic gaskets. When I pulled off the old GM head gaskets, they were ready to fall apart in the coolant areas at 126K miles. After drilling everything out, found the aluminum to be good. Should have our Cometic gaskets next week.

This same set-up on my other 1996 block has worked out very nicely with out any issues under WOT and many heat cycles from cold to 240 degrees until the fans kick in.

mtflight
11-02-11, 02:31 PM
That is great. If I have to do mine I will use Jake's studs and Cometic gaskets. After the realization of the gaskets corroding while within the Dex-Cool service interval, I switched to green and more frequent drain-refills in hopes of averting or delaying the HG corrosion indefinitely. Any pics or comments about using Cometic? They cost a bit more but probably worth every penny since this is the part that is consistently failing (when combined with said coolant).

This observation is supported by the frequency of HG cases peaking after switch to long-life coolant in mid 1996, reported in our unofficial survey of HG failure. My 98 had more than adequate cooling system maintenance (changed coolant twice beween 69K and 116K miles when the HG went).

Would be great to see pictures of the gaskets (old vs Cometic).




The gaskets just can't handle the coolant part of the block over time.

I'm currently doing another 1996 block right now with my son and with more of Norms inserts, more studs (ARP 204-4204: 2qty needed) and another set of Cometic gaskets. When I pulled off the old GM head gaskets, they were ready to fall apart in the coolant areas at 126K miles. After drilling everything out, found the aluminum to be good. Should have our Cometic gaskets next week.

This same set-up on my other 1996 block has worked out very nicely with out any issues under WOT and many heat cycles from cold to 240 degrees until the fans kick in.

chicosito
11-23-11, 01:30 AM
I am about to purchase the Jake's stud kit for my car! Looks like there are several issues with the Oem gaskets and the qualty of the Fel-Pro ones. I guess i have to go with the cometic ones. Any issues with the Cometic gaskets so far using Jake's or Norms stud kit?

mtflight
11-23-11, 02:06 AM
I am about to purchase the Jake's stud kit for my car! Looks like there are several issues with the Oem gaskets and the qualty of the Fel-Pro ones. I guess i have to go with the cometic ones. Any issues with the Cometic gaskets so far using Jake's or Norms stud kit?

Not sure anything is wrong with either Felpro or OEM but the gaskets look rotted out when they go. Cometic are stainless steel, which simply makes more sense in light of the rotted gaskets. I personally think the coolant doesn't prevent corrosion as intended or the gasket is not compatible with it. One of the two... Err on the safe side for me--I'd go Cometic which probably costs more.