: About to pull engine for head gaskets, mods and other repairs while engine is out



foxjohnc
01-08-11, 12:18 AM
Recently I was given a '97 Deville base by my sister. It is white diamond colored with 101,000 miles and a sunroof. The car is in near perfect condition inside and out. Unfortunately like a bunch of other pre '05 northstars it has blown head gaskets. She decided to buy a newer Cts as opposed to fixing the deville. I am no stranger to these engines and have done dozens of engine swaps along with gasket replacements with timeserts or norms inserts. I will be using Jakes head studs along with cometic metal gaskets.

While the engine is out I plan on doing some general repairs along with some upgrades. Heres what I have planned so far:

-reseal entire engine and transmission
-replace timing chains and tensioners
-flush tranny fluid and replace filter
-replace tcc solenoid, perform solenoid upgrade, replace iss, replace axle and converter seals
-send pcm to exatorq to be tuned and have governor removed (westers will be doing the tuning but it is actually about $100 cheaper to go through exatorq)
-new o2 sensors, fuel filter, plugs, water pump, etc

I am really thinking about installing a stall converter also but have not decided yet. I would really like a set of hotter cams as well but I dont know if it is a very good idea with the 3.11 gears. I think the converter would at least make up for the lost torque on takeoff. What do you guys think? Also is there anything elso you would repair/replace while the engine is out?

Btw to those who think I am crazy for wanting to mod a deville: The car was free so if I spend 3-4 grand fixing it up it will be money well spent in my eyes. Also, everybody is fixing up Sts's and Etc's so Id like to be different. Theres nothing like the sound and feeling of a northstar when you jam the pedal to the floor and hold on as the torque steer is trying to jerk the steering wheel out of your hands.

Submariner409
01-08-11, 09:24 AM
I think the 3.11 will give you low speed headaches with higher duration cam regrinds - you might counter some of that with a higher stall converter, but that's a fine line: too high on stall speed and the car is no fun to drive in town - and converter swapping is almost out of the question once the drivetrain is back in. Can Wester's anticipate dialing in a slightly higher idle speed for the PCM to compensate for any cam work ?

With reground/hardened cams you'll need a new set of cam followers (lifters).

For this engine (Cometic gaskets), I'd use a set of Jake's studs.

mhamilton
01-08-11, 11:15 AM
Even if you don't do the higher stall converter, you should replace the converter with a stock part. I'm sure you don't want to be pulling the trans out again after doing the solenoid and seals, because the viscous TCC is slipping too much.

Maybe also add motor mounts to the list?


...when you jam the pedal to the floor and hold on as the torque steer is trying to jerk the steering wheel out of your hands.

Not to nitpick, but there was recently a discussion on this in the Lounge. The 4T80 has equal length driveshafts, so there is no torque steer (unless maybe the car has some major suspension problems).

foxjohnc
01-08-11, 02:09 PM
Even if you don't do the higher stall converter, you should replace the converter with a stock part. I'm sure you don't want to be pulling the trans out again after doing the solenoid and seals, because the viscous TCC is slipping too much.

Maybe also add motor mounts to the list?



Not to nitpick, but there was recently a discussion on this in the Lounge. The 4T80 has equal length driveshafts, so there is no torque steer (unless maybe the car has some major suspension problems).

From what Ive seen on the forums and first hand expierences with these cars, converter failure is pretty rare. Its usually the tcc solenoid that failed. Motor mounts are a good idea, I will have to add them to my list.

Regarding the torque steer, I have owned several and driven dozens of northstar powered caddys and every one has some amount of torque steer. 95-99 devilles seem to have much more torque steer than sevilles, eldorados, and newer devilles. My '97 has a bit of torque steer exactly like my '99 did. Both are low mileage cars and my '99 had new struts and sway bar links. Neither car had any worn out ball joints or bushings, and both have had recent alignments. I dont believe I have driven a late 90s deville without noticable torque steer. I doubt several dozen cars would all have front end problems.


Submariner:

I will be using Jakes studs as I feel they are the only real solution to the problem. I will be using cometic metal head gaskets as they work well on northstars or any engine with an open deck. I will likely use felpro gaskets for everything else. I have spoken with a person from westers about the tune and they say they can compensate for the cams. Yes I was aware of the need to replace the lifters after a cam change.

Thanks for the input guys. Keep the ideas coming.

ejguillot
01-08-11, 04:25 PM
If you do get a higher stall converter, Yank Converters makes a unit for the 4T80E trans our cars use. Get a 3200 RPM stall, the 3000 RPM stall unit (which is the one I got) does not make a big enough difference for my taste. And do get a 3.71 set of gears for your trans (out of a vin 9 car) to go with the hotter cams and high stall converter.

You will need to get a custom tuned PCM to get all this to work.

mhamilton
01-08-11, 06:12 PM
From what Ive seen on the forums and first hand expierences with these cars, converter failure is pretty rare. Its usually the tcc solenoid that failed. Motor mounts are a good idea, I will have to add them to my list.

The converters don't fail, at least not to the point where it isn't drivable. The issue is with the leaking TCC apply seals. When the viscous clutch is operated under partial-apply conditions, damage occurs. It may still work, but GM says to replace the seals and the converter (yes, part of the reasoning is not to have dealers take the trans out a 2nd time, but the viscous clutch is also not as forgiving of slippage).

I don't really want to get into a debate on torque steer, but you can come drive my Eldorado and put the throttle right to the floor. Won't pull in the least. I've also driven an ETC for a while, no torque steer there either.

johnny kannapo
01-08-11, 06:55 PM
If you want to fix it leave it alone and stay with the origin of the car.

Leave it alone. You can't go wrong.

No disappointment. It is what it is.

foxjohnc
01-08-11, 08:53 PM
If you want to fix it leave it alone and stay with the origin of the car.

Leave it alone. You can't go wrong.

No disappointment. It is what it is.


Now wheres the fun in that? I am not a 70 year old grandma so if I can enhance the performance and make the car more fun to drive its a job well done. I am leaning towards the cams and stall converter, and no matter what I am having my pcm programmed. I just hope they can disable traction control so I dont have to do it the other way.

BTW long live the northstar. Even considering the head gasket problems, it is by far the best american v8 produced to date. Power and economy, what more can you ask for? Id rather put studs and gaskets on my car than work on a pos 4100, 4.5, 4.9 any day.

zonie77
01-09-11, 08:54 PM
I rented a DTS a couple of years ago and was well impressed.

Caddy picked most of the low hanging fruit but there is still room for improvement. If the Mustang and Camaro guys are willing to spend a couple of grand to port heads for 30 hp you can too! ( I don't have a couple of extra grand!) Throttle bodies and are worth some extra hp, it's just a matter of cost. The days of 30HP from a $69.00 dyno tune are long gone but there's still still power to be had, it just costs more. If I was in your situation I would consider some of the changes you suggest. I am not going to pull apart mine while it is running well.

In my experience you probably won't have to change the timing chains.

Submariner409
01-09-11, 11:23 PM
I'll echo zonie's post and add "Be careful with throttlebody and MAF so-called mods": The entire intake system now flows far more air than the 279 c.i. engine can handle at WOT - get a bit crazy and you introduce an off-idle bog and a midrange stumble - been there, done that. (:sneaky: Wanna buy a JET MAF, cheap ? :lildevil: .......EDIT: Oopps ! Wrong year MAF.)

foxjohnc
01-10-11, 12:18 AM
I'll echo zonie's post and add "Be careful with throttlebody and MAF so-called mods": The entire intake system now flows far more air than the 279 c.i. engine can handle at WOT - get a bit crazy and you introduce an off-idle bog and a midrange stumble - been there, done that. (:sneaky: Wanna buy a JET MAF, cheap ? :lildevil: .......EDIT: Oopps ! Wrong year MAF.)

Yeah I wasnt planning on any tb or maf mods. I have done quite a bit of research in the past and came to the same conclusion you have. I also do not plan on any port/polishing as it is great for a race engine at wot all day but sucks for a daily driver.

98eldo32v
01-10-11, 02:06 AM
"I also do not plan on any port/polishing as it is great for a race engine at wot all day but sucks for a daily driver".

Hmmm. That might be your opinion on the subject, but the greatest restrictions on flow are usually found in the cylinder heads.

Every cylinder head on any car that I've had apart, I've been fortunate enough to make gains with my cylinder heads.

Just take apart most engines and you"ll find a gasket mis-match between heads and intake. If the intake is split into upper and lower, there could be a mis-match there.

Underneath valve seats are where the most gains in air flow are made. After the machining for the valve seat there is usually sharp edges left over from the machining. Smoothing these edges out into the port(s) will aid in the entry/exit of combustible mixture through the head.

Air is quite "heavy" at higher rpm so removing some of these "edges" will aid in the engines "breathing" capabilities.

Most cars are exhaust restricted by design. Improvements from the exhaust valve seat to the exhaust port opening can yield power improvements.

I suppose it just depends on how far you're willing to go.

When I get my heads off, I'll be going through them to "clean" them up a bit.

Good luck with your modifications.

Submariner409
01-10-11, 09:13 AM
98eldo, I believe that you will be pleasantly surprised to find that GM has already done the port and cylinder flow turbulence design for you.

Yes, if yours truly was building an Olds 455 with a set of (?) Ka or Ga iron heads, I'd be in there with the die grinder. Not necessary on the Northstar.

Here's a cute little marine Olds 455 I built a while back - the inside of these heads is a thing of polished beauty with 4-angle valve job.

98eldo32v
01-10-11, 03:16 PM
Now,

THAT'S AN ENGINE!!!!

Unfortunately, those engines are slowly being forgotten for the hi-tech marvels we have today. Yet, with the right work those engines can muster up quite a bit of power.

Fantastic job on the 455 Sub.

Submariner409
01-10-11, 05:28 PM
Now, THAT'S AN ENGINE!!!! Unfortunately, those engines are slowly being forgotten for the hi-tech marvels we have today. Yet, with the right work those engines can muster up quite a bit of power. Fantastic job on the 455 Sub.

:sneaky: There's more where that came from - 2 more short blocks in the garage and just scored a complete W-30 with a forged crank - for $65. (Engle and Comp grind some very much fun cams for these engines - the one in the pic is bored to 461 and runs Keith Black pistons............bulletproof.

98eldo32v
01-11-11, 12:22 AM
W-30 parts are rare gems today.

Only those that have been "around" long enough to know what these parts meant in their "heyday" truly appreciate the rare find now.

The funny thing is some people are unloading these things not knowing what they are giving up, or feel everyone has forgotten about these "rare" powerplants.

Good score Sub on the W-30. Keep stocking up on the rare engine stuff.

Unfortunately, small block and big block engines modifications as "we" know them is turning into a "lost" art....

Submariner409
01-11-11, 04:24 PM
............as regards the Northstar and its ignition and fuel systems: I HATE electronic engine controls !

This puppy would be a hoot with three or four dual-choke Webers on top and a tunable HEI distributor/trigger system. Even as-is I'll bet the thing would wind to 8,500 no problem: you gotta wind up a small engine to get power - there just isn't any at low rpm (and none to be gained there, either). Small engine ??? Remember, this thing is a tad smaller than a 1963 Chevy 283 - BUT look what Ferrari has done with 3.0 liter (185 c.i.) V-12's wound to 9,000 rpm.

Problem is, with a sidewinder engine, you're stuck in the FWD less-than-wonderful performance rut.

98eldo32v
01-11-11, 04:30 PM
"BUT look what Ferrari has done with 3.0 liter (185 c.i.) V-12's wound to 9,000 rpm".

I agree Sub, but it's not like GM couldn't build such a motor, but like you said "FERRARI" vs "Cadillac"?!
The two markets are completely different, and so are the price tags!!!

Racer704
01-16-11, 02:33 PM
I think any work to the heads would be mood point if the exhust manifolds are left as is,this will offset any port work done.Now if you were to get a set of lazer cut 3/8 stainless flanges and build a set of stainless shorties that could be a path but expensive if you have to sub it out....then some spin tech oval pipe? i am just talking out load here. One other thing is to look into david visors polyquad design to use on these heads...that would be interesting venture but any major gains are in the breathing and exhusting.....JMHO

Submariner409
01-16-11, 06:01 PM
:lildevil: Good thoughts - we've all lusted for headers and decent pipes - including the crossunder and Y - but the darn trouble is that there just isn't room in the sidewinder configuration - for headers, crossover pipe, or even dual exhaust.

Some builders recommend extrude-honing the inside of the manifolds to remove weld burrs and edges. The manifolds themselves aren't all that bad, but ANYTHING would help; the engineers were saddled with space problems. A couple of members have cleaned out the inside pipe flash and welds in the manifold Y pipe.

For the 1999 and later Seville/Deville drivers, take a look at www.corsaperformance.com and the system pictures up in my album in the light blue bar ^^^. Simple install, and it does free up the system a bit. www.AutoPartsWarehouse.com

Pete1996
01-16-11, 09:47 PM
............as regards the Northstar and its ignition and fuel systems: I HATE electronic engine controls !

This puppy would be a hoot with three or four dual-choke Webers on top and a tunable HEI distributor/trigger system. Even as-is I'll bet the thing would wind to 8,500 no problem: you gotta wind up a small engine to get power - there just isn't any at low rpm (and none to be gained there, either). Small engine ??? Remember, this thing is a tad smaller than a 1963 Chevy 283 - BUT look what Ferrari has done with 3.0 liter (185 c.i.) V-12's wound to 9,000 rpm.

Problem is, with a sidewinder engine, you're stuck in the FWD less-than-wonderful performance rut.

Now these Webers are a beautiful sight - wish it was my car:
And by the way, I recently noticed that the direct injection motors seem to be getting a bit more HP/liter even on regular fuel ... impressive!

Submariner409
01-16-11, 10:39 PM
HAH !!!! Ferrari V-12. Wait until someone asks "Why is the oil filter (one of two) upside down and why are there two "distributors"? !!!!! Hot damn - back to the good ol' Ferrari and Lamborghini days........................ "Hey - what are all those velocity stacks for ???" (to put fuel/air into 12 cylinders.........) Google "vertex magneto". I like the windshield washer fluid bag...........that entire engine sounds like a precision Swiss watch as it runs.

Is that a Mid-engine car ?

Pete1996
01-16-11, 10:56 PM
It is a front engine 250 GTO, one of the most rare and valuable Ferraris, they go for over 1 Million when auctioned.
Let me find some pics, or a video - it has always been my favorite from a styling standpoint also, gorgeous:
http://en.wikipedia.org/wiki/Ferrari_250_GTO

Sorry, currently valued at 18 Million, LOL:

Video: http://www.youtube.com/watch?v=U-5JNxVVkDA

johnny kannapo
01-17-11, 10:02 PM
This might lift a headbolt.

http://i826.photobucket.com/albums/zz183/billytheshoe/2d03b864-1.jpg?t=1295315677

http://i826.photobucket.com/albums/zz183/billytheshoe/fb96e45c.jpg?t=1295315677

This N* will hold up well.

http://i826.photobucket.com/albums/zz183/billytheshoe/cammer/2a9355a7.jpg?t=1295316042

Pete1996
02-02-11, 12:19 PM
............as regards the Northstar and its ignition and fuel systems: I HATE electronic engine controls !

This puppy would be a hoot with three or four dual-choke Webers on top and a tunable HEI distributor/trigger system. Even as-is I'll bet the thing would wind to 8,500 no problem: you gotta wind up a small engine to get power - there just isn't any at low rpm (and none to be gained there, either). Small engine ??? Remember, this thing is a tad smaller than a 1963 Chevy 283 - BUT look what Ferrari has done with 3.0 liter (185 c.i.) V-12's wound to 9,000 rpm.

Problem is, with a sidewinder engine, you're stuck in the FWD less-than-wonderful performance rut.

Webers for big/small block too bad not for Northstar; a bit pricey also, LOL:
http://www.carburetion.com/weber/wildv8.asp

http://www.carburetion.com/weber/8pak/sbcpolishchrome.jpg

Submariner409
02-02-11, 05:21 PM
Yep.............nostalgia is really wonderful. To get that setup ON a Northstar (not running, not tuned, just ON) would cost $3,500+.