hey guys, got another question. I just got my head out of the shop the weekend, i got it resurfaced and they did a valve job to it. They shaved off 50 thousandths of the head. I am going to be running a turbo on my ls motor, and was looking into getting new pistons. I was going to run 9:1 compression pistons, but now that they took 50 thousandths off my head i was wondering if i should go with a different ratio????? if anyone can help please let me know. Thanks

 

Taking 0.050" off has increased your compression ratio a little. I imagine you had good reasons to choose a 9:1 CR, so keep that ratio. But when you do the math to get your CR, you have to take that 0.050" into account.

 

there is a good calculator on cspeedracing's website. check it out.