924Board.org

-nick · Guest

hi all,
i threatened to post a pic of the copper gasket i used which shows how the compression leaked out:

you can see the lines from the cylinders to the outer edge where the compression pushed out.

this was a .050" thick gasket. if the stock NA is .067" and the rule of thumb is .1 compression points for every .005" then i was running ~9.6:1 with euro pistons.

as you can see, you must o-ring the block even with this little amount of compression on a copper gasket. i didn't think i would need to worry about it until the compression approached 11+, but there are just not enough headbolts to hold it in without an o-ringed head.

just an fyi, i thought it was an interesting pic. someday i'll pull the engine back out for a refresh and have it o-ringed.

-nick

[ This Message was edited by: -nick on 2002-04-13 01:39 ]

AznDrgn · Guest

What exactly is having the head O-ringed?

-nick · Guest

you cut a groove in the head around the circumfrence of the cylinder and insert a bead of metal in the block. so when you mate them there is a lock around each cylinder to hold the compression in.

it's not an expensive process but requires giving the machine shop your head (not such a big deal) and your block (a pita!).

this can be done vice-versa, with the groove in the block etc.

after this process you will never have another headgasket problem. some are hesistant and say that the headgasket is a safety valve keeping pistons and valves from being damaged. i've never heard of anyone having a problem on a well setup engine, it's when you start to skimp that things go wrong.

-nick

AznDrgn · Guest

Hmm sounds like a pretty good idea. Are there any advantages to which side you do it on? Will this help for turbo charging applications when you keep the stock 8.5:1 compression?

AznDrgn · Guest

Oh yeah and approximantly how much is it?

-nick · Guest

i'm not sure if there is an advantage one way or another. give any auto machine shop a call, they're usually pretty interested when you start talking about things like this to them. as for price? i can't really remember what i was quoted, i'm thinking it was under $100 for all four cylinders.'

it works great for any cars that have problems with headgaskets. turbos especially.

-nick

AppleBit · Joined: 16 Nov 2002 Posts: 1516 Location: Minneapolis, MN

I had the same exact problem with my copper head gasket. I am going back to the original head gasket. Less mess.

Mine lost compression as well as dripped anti-sneeze

For Sale: One copper head gasket

- Jon McCullough

Cbass · Guest

I'll buy that for a dollar!

I'd want the groove to be in the block, as theres more room to work with there.

Richard · Guest

Just a quick question. Did you guys use any gasket cement? I thought copper head gaskets were suppose to be sealed with NAPA Hi tack sealer or GM gasket compound or equivalent.

-nick · Guest

you can use any hylomar sealer. i talked to the manufacturer of mine and he concurred that the motor would not hold in the compression with o-ringing. a flathead ford with a gizillion headbolts yes, 924's with just 8 can't hold it in.

-nick

AznDrgn · Guest

So there is really no point in doing it for our cars?

-nick · Guest

sorry, the post should have said "would not hold the compression in withOUT o-ringing". if you're running high compression or lots of boost it's worth it.

-nick

924 turbo · Guest

-nick · Guest

aha!

sorry, that should be 10 headbolts. this massachusetts heat wave is really going to my head.

-nick

Vince Ponz · Guest

I have a Eruo 85 block with 9.3 pistons if anyone is interested.

I am in NYC area