I just finished putting together the bottom end of my 427.I have speed pro forged pistons with 125 thousandts dome the flat part of the piston comes out of the block 22thousandts,I think the norm is 40thousandts clearance between piston and head am I correct in saying that a 62thousandts copper head gasket will solve the problem?The heads are 119cc so I don't think I'll have too much compression for pump gas.

RC, (name ??)
The block must have been milled a bunch sometime in the past. I have never seen TRW pistons come out of the deck, they are usually down a bunch. If this is a street driven car, instead of using a solid copper gasket, which WILL leak water. Use two of the shims that Fel-Pro makes for this exact problem, then use a regular Fel-Pro permatorque gasket on top of the shim. A lot less chance of any water leaks. The shims are .022, so you will be pretty close to perfect with a
039" gasket.


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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

You can use a copper head gasket and it will not leak go and buy some hylomar at your local auto parts store or they have some copper spray we use them on 2500 hp blown alky motors and all our nitrous motors we build for the street and racing never had a problem good luck ..cube

<BLOCKQUOTE>quote:</font><HR>Originally posted by cube:
You can use a copper head gasket and it will not leak go and buy some hylomar at your local auto parts store or they have some copper spray we use them on 2500 hp blown alky motors and all our nitrous motors we build for the street and racing never had a problem good luck ..cube<HR></BLOCKQUOTE>

I went and got the gaskets today and I did buy a can of hylomar when i opened the gaskets to read the instructions they reccommended o-rings whats that all about do I need to groove the block or the head I'm sure the o-ring needs a groove to rest in?

Listen to Bill......

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Sid Coleman, 71 Ragtop
TC (Gold) #174, MCC #347,
Aces #5457, N3JHV@bellatlantic.net

<BLOCKQUOTE>quote:</font><HR>Originally posted by BillK:
RC, (name ??)
The block must have been milled a bunch sometime in the past. I have never seen TRW pistons come out of the deck, they are usually down a bunch. If this is a street driven car, instead of using a solid copper gasket, which WILL leak water. Use two of the shims that Fel-Pro makes for this exact problem, then use a regular Fel-Pro permatorque gasket on top of the shim. A lot less chance of any water leaks. The shims are .022, so you will be pretty close to perfect with a
039" gasket.


<HR></BLOCKQUOTE>

Thanks bill,but thats not what I wanted to hear(water leaks).The gaskets I bought are SCE and they assured me if I followed procedure with hylomar spray they would'nt leak I sure hope not,we'll see.Oh yea RC-Ron Carter.

<BLOCKQUOTE>quote:</font><HR>Originally posted by BillK:
RC, (name ??)
The block must have been milled a bunch sometime in the past. I have never seen TRW pistons come out of the deck, they are usually down a bunch. If this is a street driven car, instead of using a solid copper gasket, which WILL leak water. Use two of the shims that Fel-Pro makes for this exact problem, then use a regular Fel-Pro permatorque gasket on top of the shim. A lot less chance of any water leaks. The shims are .022, so you will be pretty close to perfect with a
039" gasket.


<HR></BLOCKQUOTE>

Hey Bill, Ron again, just got off the SCE website,now I understand O-ringing the block .I have built quite a few motors before ,but they were pretty much standard rebuilds .I have never had to get this deep into one. I will definatley be o-ringing the block this week!

What is the reason for o rings on the block? Is it do to being decked so much? With those heads compression doesn't sound like an issue. O rings aren't going to help a water leak situation.

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1969 SS 396 Camaro/Th 400/355s.(454 now)
Not a Chevelle but the BBC guys are here!

since I posted last night I found what you are saying is true so now I'm not going to o-ring the block.

Listen to Bill copper gaskets leak even with O rings. You can live with it on a race only car but don't run them in a street car. If the block is decked that much you will need to check you intake manifold fit very closely.



[This message has been edited by Mike Feudo (edited 02-11-2003).]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Mike Feudo:
Listen to Bill copper gaskets leak even with O rings. You can live with it on a race only car but don't run them in a street car. If the block is decked that much you will need to check you intake manifold fit very closely.

I think I have talked to a hundred people today about this problem,and 99 say its not a good idea for a street mtr.I talked with my machine shop,we came up with milling the flat portion(not the dome)of the piston the .022that is coming out of the deck and using a standard gasket,I believe this will be the best fix in the long run.BTW I have a set of .062 copper gaskets for sale ha ha.

[This message has been edited by Mike Feudo (edited 02-11-2003).]<HR></BLOCKQUOTE>