Headgasket Options

[Spooling]

So what are my options now - concerning headgaskets?

Last time around I used the set-up that Jay researched - namely the 2-Stacked GM "Steel-Shim" Headgaskets (P/N # 25524599) with that "Gorilla Snot" smeared everywhere.

I will certainly say they worked !!!

It seems that these are "Discontinued" from GM.

I also saw that the system is offered from Jason Cramer - yet the headgasket is a "single".

What is the thickness of "one" of the steel shim gaskets defined above (P/N # 25524599) - or rather, what is the thickness of the 1987 OEM Headgasket (sb 2* thickness of 1 P/N # 25524599).

Lastly, I have had my block decked, and the cylinder heads (steel) have also been surfaced.

I would like to keep CR as close to stock as possible - and am curious if the block being decked coupled with the heads being surfaced coupled with the availability of only 1 steel shim headgasket offered by Jason will change my CR, and if so, from what ratio (stock) to approximately what.

As always - I appreciate all input - and wish to say "thank you" in advance sharing with me your knowlege.

 

[BIGPSI]

i have about 16 NOS gm gaskets i would sell,as i put cometics on my car and they are working great. pm me an offer if you want the gm ones. would prefer to sell all at once

 

[kidglok]

Why don't you just run cometics? You might need them to be thicker then stock due to shaving the heads and block

 

[hensleyt]

Is higher CR bad?

 

[kidglok]

stock was .060, i believe the 25524599 to be .030 each so 2 would bring you back to stock. how much was taken off the bock/heads?
higher compression is good, as long as you have the octane to support it

 

[Nick Micale]

The 25524599 GM head gasket is .018" thick, so "stacking" them will give less than .040" compared to the stock or Felpro composition gasket at .060".

We have used many of these steel shim gaskets, and are very forgiving on 8 bolt heads, but they need periodic re-torquing.

There is NO head gasket that is "blowout proof" on a turbo Buick, especially on 8 bolt heads. This provides a great "fuse".

On 14 bolt heads, most any head popular gasket will hold up, but an issue, or bad tune, will take out a piston or rod instead?

 

[Spooling]

cometics on my car and they are working great

Are these "Cometics" a steel re-inforced gasket surrounded by a "composite" type material - possibly similiar to the OEM supplied headgasket?

I also wish to ask - that you have no sealing issues with H2O?

What is the thickness of this gasket set, and where might one purchase a set?

Many Thanks !!!

 

[Spooling]

The 25524599 GM head gasket is .018" thick, so "stacking" them will give less than .040" compared to the stock or Felpro composition gasket at .060".

====================
So, based on your "experience" - can you give an approximation - concerning the following - please:
----------------
1. I believe stock CR ~ 8.5:1 - yes?
2. Using a stock 0.060" headgasket on a "decked" block w/ surfaced "steel" heads would yield ~ what CR?
3. Using a stacked steel shim headgasket configuration at ~ 0.040" on a "decked" block w/ surfaced "steel" heads would yield ~ what CR?
--------------
I can say that I was told only that amount of material was removed to make the surfaces "flat" - so I do not have an answer concerning "how much" material was shaved off of the heads / block.

Many thanks for sharing this information !!!

 

[BIGPSI]

Are these "Cometics" a steel re-inforced gasket surrounded by a "composite" type material - possibly similiar to the OEM supplied headgasket?

I also wish to ask - that you have no sealing issues with H2O?

What is the thickness of this gasket set, and where might one purchase a set?

Many Thanks !!!

cometic's are a multi layered steel head gasket. i believe they come in several sizes and i have had no trouble with any leaks

 

[Nick Micale]

====================
So, based on your "experience" - can you give an approximation - concerning the following - please:
----------------
1. I believe stock CR ~ 8.5:1 - yes?
2. Using a stock 0.060" headgasket on a "decked" block w/ surfaced "steel" heads would yield ~ what CR?
3. Using a stacked steel shim headgasket configuration at ~ 0.040" on a "decked" block w/ surfaced "steel" heads would yield ~ what CR?.....................

1. The "advertised" CR for the turbo engine is 8.0:1. Most all manufacturers engines, we have found is actual CR is always lower than advertised. With the performance Buick V-8 and V-6 it is lower by at least 0.1, or in the turbo version that would be 7.9:1.

2. A normal clean up cut on heads and block may yield one or two-tenths.

3. Using a 0.040 gasket could give 1/2 a point from 7.9 to 8.4.

On street builds we normally shoot for 8.5:1. With our local crap pump gas at 91 octane, this will NOT even support stock compression at 15-16 psi.

 

[Spooling]

1. The "advertised" CR for the turbo engine is 8.0:1.

A normal clean up cut on heads and block may yield one or two-tenths.

Using a 0.040 gasket could give 1/2 a point from 7.9 to 8.4

-------------
Excellent information. Many thanks for sharing this !!!

Ed

 

[Spooling]

cometic's are a multi layered steel head gasket. i believe they come in several sizes and i have had no trouble with any leaks

-------------------
Please forgive my absence - concerning being out of touch - yet whom are the recommended vendors that supply these headgaskets - as well as other Buick V6 Performance goodies?

ATR is gone now, Bowling Green Customs, Kenne Bell also, Poston's maybe, Kirban...

I think by me posting those Buick Vendors - I am most-likely "displaying" my long-time ownership with my Buick

 

[kidglok]

cotton usually has the 0.40 and .060 cometics on the shelf

 

[BIGPSI]

i have about 16 NOS gm gaskets i would sell,as i put cometics on my car and they are working great. pm me an offer if you want the gm ones. would prefer to sell all at once

i only have 8 left. if anyone needs them send me a pm

 

[Spooling]

Sent you a PM.

 

[BIGPSI]

Sent you a PM.

got it. sale pending

 

[rag231]

If the compression goes up may sure you check the piston to valve clearance.