Copper head gasket

[Pat D]

Has anyone used the copper head gasket from 034 with an o-ringed block?

They have two types available, one with metal shims and the other without. I have heard some engines getting water leakage with the shimmed gasket in high boost applications.

[JP]

What bore size are you running. 82mm or less run stock multilayer gasket it's stronger. These have a compression ring built into them which is effectively your o ringing of the block when you are using your copper gasket.

Now due to the nature of o ringing you will never have a perfect 360 degree compression ring as the wire has two ends to it like a pistons ring with a gap however small it may be. Hence the move onto mls gaskets.

If you open up the mls bore you will end up eating into the compression ring making it no better than a fibre style gasket used on the na cars. So this is not an option either.

So if I had to go over 82mm because a customer was stupid enough to have allready overbored their engine to that then I would purchase a 82.5mm 7a fibre gasket which is good for upto 83.5mm and o ring the block in conjunction with one of those. Ring placement however becomes crucial for it to work correctly and will need to be done by someone that has experience in that field using this method.

[Pat D]

I'm at 82.5mm and I plan on running high boost to reach 600-700hp. 034 have an MLS at 82.5mm http://www.034motorsport.com/engine-...hyd-p-113.html, after reading issues with copper gaskets I've found info on builders using copper wire for the o-ring and an MLS gasket with great results. Or do you think the MLS alone should hold 35-40 psi?

I have a reputable drag engine building company doing all the specialist work, this is the first 5cylinder job for them. I will assembly the head on the block at home though.

I thought a fibre gasket wouldn't like a stainless o-ring wire pushing on it resulting in perforation/damage?

[JP]

An mls will hold 40-50psi if the sizes are all 100% the block is decked the head is skimmed and you torque it all down to 95ft/lb on the 12mm ARP's and check them frequently.

As for the 034 gasket that's a normal of the shelf one and yes if you don't open the combustion chambers to match bore size there is enough clamping load for most situations as the gasket doesn't physically encroach fully on the bore. Not ideal but you can get away with it. If you were to use one of those and o ring the block just behind the original mls firing ring that would work too.