I have a big block 572 that is supercharged and the block is o-ringed. What type of head gaskets should i use. I ordered felpro mls, but the bow out on the left bottom of each cylinder and miss my o-ring in my block, bore size is 4.627.
thanks

all the o-ringed blocks that I know use solid copper..

Try Cometic. They will make head gaskets any bore size and thickness you want. What kind of gasket came off from it? Good Luck.

I have always used solid copper with an o-ringed block and heads. I don't know that the Cometic will work with o-rings. If you use copper, you will have to silicone around the water passages.
Eddie

TG,

You have to use copper gaskets if the block is "O" ringed. There is generally a corresponding "receiver" groove machined in the heads also. What was on the engine before ?

Depending on how and exactly where the o-ring was installed, you might be able to take it out and use a conventional gasket, but dont try it without having someone knowledgeable look at it first.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

I had a turbocharged Ford Mustang that we orginal had stainless steal o-rings in the deck of the block and had to use copper head gaskets. Two problems with cooper head gaskets. First they leak! I used RTV silcone and then also tried Permetex High tack spray and still had issues with external coolant leak. The other problem is they will never blow out which could be a bad thing if your tune isn't 100%. You will melt pistons before the headgasket blows out.
So after dealing with cooper head gaskets my machinest removed the o-ring in the deck of the block and machined the 15 thousands grove out of the block. Then switched to MLS gaskets and never had and more issues. Oh yeah car ended up making 1138rwhp from alittle 349ci stroked 302 based smallblock ford with 80mm turbo
Erik

what came off is a plain composite gasket with a steel ring, no mls. I mean it did last 200 hrs so i guess i could just use the same style. I really don't want to use copper due to water leaks

t,
When you say the block is o-ringed ... does it actually have an oring protruding from the deck surface or just a groove cut in the deck ? If you had a composit gasket on there and it worked ok, then I would replace it with the same exact gasket, it must hit the ring just perfect to seal ok.

you will have issues with cometic on a bore that big. Copper O-Ring from Bob at Performance Gasket Concepts is the way to go. He has graphite inserts around the water passages.

if the block is o ringed and the head does not have a reciever groove,even with the best sealer,it might leak water in a marine application,this is due to the increased water pressure.if the engine is apart,get the oring groove milled off,it is usually less than .020 deep,then use the cometic multi layer gasget.if the head is machined with a reciever groove,have the head milled to remove it,usually only .015 to .018 deep.if you do have the reciever groove :in head&oring in block,and dont want to get things machined,use a copper head gasget,and a good sealer,if you need to know what sealer to use,let me know and i will go to the shop and tell you what i use.