GM 12557236 head gaskets

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
hbps1978
Member
Member
Posts: 106
Joined: Fri Feb 11, 2005 12:41 am
Location: Virginia

GM 12557236 head gaskets

Post by hbps1978 » Fri Feb 08, 2019 5:49 pm

I was wondering how many of the professional engine builders/machinists here have built a GMZZ4 - GM602/604 crate engine and used the GM 12557236 head gaskets? I'm wondering if these composite head gaskets need any Permatex high heat copper spray a gasket installed on them or if they are fine to use "as is" out of the package? I'm building my own version of a GM ZZ4 street engine for a weekend driver/cruiser. Thoughts on these gaskets? Thanks
Performance is my passion

dfarr67
Pro
Pro
Posts: 296
Joined: Sat Jul 27, 2013 7:14 pm

Re: GM 12557236 head gaskets

Post by dfarr67 » Fri Feb 08, 2019 6:37 pm

I've used them both ways on a SBC- still running. ARP studs/GMPP graphite.

User avatar
BOOT
Guru
Guru
Posts: 1538
Joined: Fri Apr 09, 2010 6:23 pm
Location: Michigan

Re: GM 12557236 head gaskets

Post by BOOT » Sat Feb 09, 2019 6:56 am

I plan to use some sim composite gaskets on a sbc head swap and prob will copper spray the deck side since it's not worth removing and resurfacing, heads will be surfaced so we'll see if I feel like spray both sides of the gasket at the time.
I know as much as I can learn and try to keep an open mind to anything!

If I didn't overthink stuff I wouldn't be on speedtalk!

gramps
Member
Member
Posts: 75
Joined: Fri Jan 23, 2009 7:16 am

Re: GM 12557236 head gaskets

Post by gramps » Sat Feb 09, 2019 8:10 am

Used many times on the 604 with and without copper spray no problems either way. ARP hardware for the washers.

BLOCKMAN
New Member
New Member
Posts: 10
Joined: Sat Feb 09, 2019 9:23 am

Re: GM 12557236 head gaskets

Post by BLOCKMAN » Sat Feb 09, 2019 9:28 am

Those gasket do not utilize the center cooling hole for cooling between the two center exhaust valves like the modern performance gaskets do.

engineguyBill
Expert
Expert
Posts: 976
Joined: Fri Feb 26, 2010 11:15 am
Location: Gold Canyon, AZ

Re: GM 12557236 head gaskets

Post by engineguyBill » Sun Feb 10, 2019 10:23 pm

Gasket sealer is not recommended with composite head gaskets. Just make sure that the gasket sealing surfaces are straight and clean. Also make sure that the block threads and head bolt/stud thread are clean and dry. Use thread cleaning tools for cleaning the threads, not tap and die set. Torque the bolts/studs in several steps following factory recommended sequence and tighten the fasteners to the maximum recommended torque and NO MORE.
Bill

SAE Member (28+ years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist

"Do what you can, with what you have, where you are."
- Theodore Roosevelt

Sumtingwong
New Member
New Member
Posts: 29
Joined: Mon Feb 11, 2019 12:03 pm

Re: GM 12557236 head gaskets

Post by Sumtingwong » Mon Feb 11, 2019 12:20 pm

They seal up good without sealer. Absolutely no fun to clean up that gasket off of surfaces.

midnightbluS10
Expert
Expert
Posts: 541
Joined: Sun Oct 20, 2013 8:41 am

Re: GM 12557236 head gaskets

Post by midnightbluS10 » Mon Feb 11, 2019 1:18 pm

I believe those were initially indicated for Corvette engines with aluminum heads, hence there being no center cooling hole. As I recall, thats what I was told. I don't know how true it is or whether that's the reason there are no center cooling holes in that gasket set.
JC - Precision Guesswork & Expert Up Arrow Manipulation

Post Reply