Engine Setup: 357cid w/AFR 195, Comp XE274, KB Flat-tops, RPM Air-Gap, 750 Speed Demon DP, Crane Gold RR

Deck Height: .045"
Combusion Chambers: 68cc
Valve Reliefs: 5cc ???
Bore: 4.040"
Stroke: 3.48"

Should I stay safe and go with a standard .040" composite head gasket which would give me a large quench area or is it OK to use a .015" steel shim gasket which would lower the quech area to something more optimal. I figure quench area is more important than CR, but I am not too sure about using a steel shim gasket with aluminum heads. I figure I'd be about 9.5:1 with an .040" and about 10.0:1 with an 0.015" gasket.

 

How do you know the deck height? Hopefully this short block isn't already assembled. But even if it is, it's not too late to do it right.

Deck the block. You'll never get the quench right with that much deck. But, the CR will be so low, the quench won't matter anyway. It's already lower than it should be with iron heads, let alone what it needs to be with aluminum ones.

CR is more important than quench. However, the need for quench is dependent on CR. As CR increases, so does the importance of "quench"; that is, at low CRs (less than 9¼:1 or so, which is where you are now) quench is insignificant, becaue the engine has no tendency to detonate anyway; but at 10½:1 or above, where your motor needs to be at the very lowest, it becomes far more important.

Deck to block to .000", run the 1010 .039", and mill a little off the heads to get the chambers down to 63-64cc. .020" - .025" ought to do it.

 

I got the deck height from the engine builder. Yes, the short block is already assembled. I have used it before with factory castings am switching to AFRs in the next few weeks. The plan is to run this shortblock for a little while and then to move the top half of this engine onto a forget 383 or 406.

 

first thing i thought of is .040 right? i'd double check the info and if it is .040 i'd back up a step or two and have it zero decked.

 

Vendor: Fel-Pro Performance Gasket
Product Line: Fel-Pro Performance Head Gaskets
Material: Steel Core Laminate

Head gaskets that seal.

Chevrolet: 262-350, steel shim, .015 in. compressed thickness, 4.100 in. gasket bore, 3.2 cc compressed volume, head gasket
* For use with cast iron or aluminum cylinder heads


http://store.summitracing.com/partde...art=FPP%2D1094