BS2011

iTrader: (2)

Hey guys I have a 408 with -3cc flat top pistons with some katech 243's (not milled). I plan on running e85 my question is will my compression be to high to run boost or should i change to the 317s with a thicker gasket? I already have a set of bare stock 317s.

slowlsx

iTrader: (28)

what is your compression equal with those pistons? I have a feeling you will be fine. there are guys running in the 12 to 1 range with E85 and I don't think you will be anywhere near that.

BS2011

iTrader: (2)

I think Im in the ball park of 11 to 1. Its a 408 lq4 with callies rods, callies dragonslayer crank, and wiesco -3cc flat tops. With the 243s. Im hoping I will be fine to use the 243s since they have already been ported.

DavidBoren

The 243's should be fine. 11:1 static compression isn't going to be an issue with e85 and a halfway decent tune.

I guess I should specify that 11:1 compression isn't going to be a problem with proper quench, and a cam that properly keeps the dynamic compression under 9:1, preferably closer to a 8.5:1 ratio.

I would definitely use the ported 243's...

slow trap

iTrader: (22)

unless my math is off i think your scr will be around 12:0 or so. my -12 piston 408 with 59 cc heads is 11:7 with a thin gasket. yours has a +4 cc diference. no experience with e85 yet but everyone that runs it seems to be able to get away with really high compression and boost.

BS2011

iTrader: (2)

well I may be wrong. My heads are still stock 64cc and I also have a .052 compressed gaskets. Ive been around turbo cars for awhile, but im just trying to make sure im not building a bomb lol.....