TOPIC:

your actual cranking pressure is more of a concern than the pistons it depends on your camshafts if your valves say open a long time the actual pressure will be lower inside motor.does this make sense,now im confused!

Who knows? Around here we might see a motor with tractor cams and a power takeoff for running sawmill, pump, and possum plucker.

12-12.5: compression with streetable cams is going to result in a short lived motor, detonation will blow holes in the pistons unless you run racing gas in it (or alcohol). You could run long duration cams with lot's of overlap to blow part of the intake charge out the exhaust or back out the intake to lower effective compression, but it's not going to be any fun to ride on the street.

Heat is not really the problem, piston killing detonation is what you have to worry about

Also, a thicker head gasket (or base gasket) to lower compression is not a good way to go. This will eliminate quench, or squish, altogether, greatly slowing the burn and requiring excessive spark advance to run right, therefore still being "ping-prone", even with lower compression.
Run it at 12.5:1, use moderately hot cams, and build yourself a 'still to make your fuel, mixed with a little gas or other substance to keep from scouring your cylinder walls with straight alcoholB)

Here's a pic of the piston. I decided not to buy the set, since it looks like:
1 - high compression is unusable on the street (trouble with longevity and starting)
2 - lowering compression using a thicker gasket means trouble burning the mixture, meaning lots of trouble getting the ignition timing right.
Either way this set will mean lots of time, trouble and expense to get working right.
If anyone is interested, I can post the sellers' details. Location: Netherlands, near Amsterdam.

Post edited by: Zthou1977, at: 2006/05/08 07:23