alloy heads

ron whats the least i can saftley have between top of piston and chamber,,im having a spot of trouble with these egge pistons shape on the tops,,im using best gasket which are .60 thou thick
 
Put the heads on with no gaskets, turn the engine over... My heads hit, I used feeler blades to measure the amount of interferance... Took time and patience...

From what I've heard, I've decided to use .040 clearance...
Karl
 
Make sure you check your piston to head clerance. Best gaskets are great. They will compress to 45 thousand. The crown on Egge pistons is not correct. I dont use them for that reason. There are much better pistons out there that Egge. Dont know why they cant get it right.
 
I really wish Egge would get their act together with the 4'' merc pistons. They dont seem to care that the crown is too high and hits the heads by 40 or so thou even on stock un modified cast heads.Its been the same issue for a few years. Please Egge admit this error and modify your pistons. This is not an isolated problem with 4'' stroke mercury cranks and pistons hitting the head. the piston pin is the same height as a stock Merc piston but the crown is too high and a different radiius. It requires fly cutting of the head or milling the pistons.
 
Quickchange34

You mentioned there are better pistons out there.
Can you suggest ( in your opinion ) who makes the best one's?

THANKS
BILL W
 
The Edelbrock recommendation that came with the aluminum heads I bought is for 'Felpro copper sandwich gaskets part no.s 1055 and 1056' (49-53). This is the manufacturers recommendation but I understand some people use composite gaskets for these heads. What is best?
 
I dont think anyone fom Egge reads this forum. Ross are the ducks nuts in pistons in a higher stress application , but still Egge merc piston should work but dont.
 
Ross are racing pistons and must be fitted with larger clearance. I used Egge Pistons in all my engins. The few times I;ve used Ross pistons (Hydro and Bonneville engs) I had to redome the heads to get the clearance I wanted.
Spending thousands of dollars building an engine combustion chamber modifications are part of a well built engine.
To answer the question. For most applications .050" has worked well for years, so now we're tighting it uo alittle more down to .040. Heavy pistons will stretch the stock rods. Ross pistons and H beam rods could probably run less. SBC run .035".
I use the aluminum ball method of checking clearance on several locations of the piston.
 
thanks quick change ive found that out the hard way its about time egge was told about this dam problem
 
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