Roots To Screw Blower

I have a 526 kb, 1471 roots with 12:1 cr. using 40 thousand head gasket with ample valve clearance.

Q. If I use the same 526 kb with a psi screw, How much piston cr. would need to have? ( ex. flat top 9.0 ? something more or less ) Just need some Ideas from psi screw blower racers, and engine builders Thanks.

 

don't run any more than 11 to 1 compression. i would put an .080 head gasket on the motor to be safe.

 

acording to the P.S.I. book that you get when you buy a new Screw, 10.0 /1 to 11.4 /to 1 is recomended. you might think that .4 wont make a differance, but like the old maid that peed in the ocean said " every little bit helps "

 

359Pete,

Please check your private messages.

 

I'm running 12.1 in my 451 fat 5 d psi combo at 68% over with no problems timing and overdrive will govern how much comp you can run.