sross

iTrader: (1)

I recently picked up a basic short block for my truck. I'm putting a baby cam in it and also wanted to bump the compression a bit so I bought some Cometic .040 head gaskets. However, after looking at the short block, I noticed that the pistons stick up out of the bore (I measured about .010 above the deck). That was a surprise to me and that leaves me with .030 clearance between the pistons and heads (pistons and valves have plenty of clearance).

Is .030 too tight? This is a truck motor that will not see crazy RPMs, nitrous, FI or anything like that.

I was hoping to pick up a little C/R since the new pistons have about 4cc's of valve reliefs cut into them. It looks like I'll have 9.78:1 with stock gaskets (.051) and 10.02:1 with the Cometics (.040).

Thoughts?

03sierraslt

iTrader: (22)

Personally I wouldn't go below .040 with a stock rotating assembly.

Atomic

iTrader: (42)

Its effectively the same thing as milling the heads 0.010" which is quite a bit. You will probably be fine but you can always check PTV clearance when you have a head on.

03sierraslt

iTrader: (22)

For PTV yes, for quench milling the heads doesn't change it. Or are you saying something different? Non the less .030 quench is really tight.

Atomic

iTrader: (42)

No, you are right, quench wouldnt change with milling. I agree 30 is tight, but if this really is a low-rpm, non-power adder deal then he should be fine.