Who here runs an O-Ringed block? Leaking head gasket problem!

madscientist said
Several things.

Unless you have a certain type of Fel-Pro gasket and you have o-rings, the gasket must always be copper.

2. I know it's done all the time (and no matter how many times it's done this way it's still WRONG) but NEVER EVER run just an o-ring in the block. There should be a groove machined into the head (I always put the wire in the head) and another groove put into the block (aka receiver groove). This gives the displaced copper somewhere to go. If you didn't add the receiver groove they will never seal.

3. How much compression? Unless you are over 12.5:1 and refuse to use studs there in no need for o-rings.

You have a fairly long post without much info.

If the original install was done correctly (both grooves, dead soft copper gaskets, correct sealer on the gasket) and you are still fighting water leaks that use a good block sealer and live with it.

You can take the engine apart and add the receiver grooves if you don't have them, or, just machine the block down and eliminate the grooves. Then order a Cometic gasket that is thicker by the amount that you milled off (for example, if you have a .039 gasket and machine .035 off the deck to get rid of the grooves order an .080 gasket).

You are right. I do not have a lot of info for you guys yet. I guess I was more looking for what people do with these blocks and get successful sealing. I will get my receipt book out when I get home and find the part number for teh gaskets. The reason the block is o-ringed is because it was 14:1 CR. So yes it probably needed it. We brought it down to 11:1 so I can run 91 octane, no longer needing the o-rings. But the o-rings were there and nothing to do about it. The heads are NOT machined with a matching groove. It does have ARP head studs. Here are pictures of the engine apart.

The engine builder used the same gasket as before since it did not leak when I bought it. But he also said "I used the same gasket part number that was used before. That gasket is not really designed to be used with o-rings in the deck of the block." I would imagine it's copper but I really don't know. The engine is one thing I really didn't get my hands into. He believes that the o-rings are not allowing the gasket to see the clamp down force that it needs to seal the coolant passeageways. I honestly don't like the idea of milling the block down. The pistons are custom made and they are zero decked in the block. I don't know that ending up with an out-of-the hole piston is ideal, but maybe that's an option.