Has anyone milled out their OEM pistons to make them lower compression for use in boost applications? The idea just struck me and I began thinking about it more and more. Now i realize OEM pistons are cast, not forged, but would that make a big difference at say 15psi w/ stock rods-Lets say I lowered compression to 9:1. What I am asking is if the cast pistons/ rods would give out…
stock LS is 9.2:1, so whats your point?
what are you talking about? Thanks for the info man :gunleft:
the compression on regular ls pistons is already 9.2:1 so why go through that trouble to lower it .2? you would be better off getting a thicker headgasket, the point of getting forged parts is they are stronger and handle heat better, the ls pistons will run you just fine, hell xenocron hit 300whp on all stock ls
proper tuning is key, that’s why he could extract that much. So long as you are not detonating, the pistons will hold up to x amount of boost. The question is how much boost and for how long.
The real question is power output and how many times your motor sees all that power.
ring lands, rings and rods are the weak parts on LS motors. Mine will only last so long I imagine if I keep raping it at the track like I have been.
milling the stock pistons is a horrible idea… the more matarial you take off the top the less ringland you will have, the easier they will break. you would be better off leaving them alone and getting a thicker headgasket…or stacking two headgaskets together 
Okay thanks guys, just was sitting wondering about lowering my compression on the b17 and this idea came into my mind. Thanks for the info!
B17? you can put LS pistons in it…~9.04:1 C/R… but i would just buy some aftermarket pistons…