View Full Version : Built KA: HG and O-ring Question

MaxType 240
12-27-2004, 06:38 PM
The block is already checked/tanked, bored, decked, etc and I remembered about o-ringing late in the game.

I'm keeping my existing turbo/fuel setup and I'm going to go w/ an OEM HG. (Head, forged pistons/rods make for one overbuilt engine for now)... If detonation occurs, I'd rather have the HG fail first then the expensive goodies. I'm gonna invest in ARP main/head studs to ensure the HG is the weakest link. With my line of thought, should I o-ring the OEM HG?

The shop will be assembling my head 1st week of Jan (3-angle valve job, Ferrea valves, springs, retainers). I should have all the parts and pieces mid-Jan and I'm gonna let them assemble the entire thing.

Your experiences and thoughts are appreciated!


12-27-2004, 06:47 PM
The OEM headgasket has a metal ring around the cylinders as it is. DaveEEE had more than a few problems when trying to O-ring and run a stock headgasket.

MaxType 240
12-27-2004, 08:15 PM
Rick summed up his experience here:

Wow, I will clue you in as to why an O-Ring is a BAD idea.

I originally had an o-ringed block and stock HG with stock head bolts. I never had any problem until I toasted a motor for stupid reasons. After the new motor was built I kept the same setup and then blew a HG one night. I then decided to go with ARP's and stock HG, still keeping the o-ring. It just does NOT work, the way the ARP's tighten down isnt the same as the stock HG and it would leak water into the cylinders because it wouldnt bite into the HG. After trying many different combinations, and burning up 4 HG's in the process I finally took a bastard file and filed down the o-ring until it was flush with the deck of the block. I then put in a stock HG with the ARP's and had NO problems....until 26psi where I started lifting the head. I am going to go to ARP's + Cometic for next season as well.

12-27-2004, 08:27 PM
I agree that its a bad idea to try to use an o-ring on a gasket that isnt designed to accept one. On my current motor, I am using a cometic gasket with a copper o-ring deep set in the block. The copper o-ring will crush and keep the coolant sealing problems out of the picture. The second motor I am building for my car will be using a really crazy setup. I will be using a stainless steel shim instead of a gasket and a nitrogen filled o-ring set in the block. This will ensure I will never blow a head gasket.