I have a 383 Stroker built for a 200 shot of nitrous. Now that being said. I want to switch gears and go Turbo.

I have wiseco 3cc pistons and wiseco GFX rings and
I currently have ported 243 heads with 59cc so my compression is around 12.1 to 1.

I will be running E85.

I plan and going with a set of 317 heads and a new head gasket to help lower compression.


Should I
A--- Pull the block and swap the pistons and rings for more negative CC to lower compression and keep my 243s and just swap the cam.
OR
B--- Just leave the the block as is and swap the cam and heads?

Thanks
Josh

 

You have a lot more than 11.3:1... with a .051" gasket and assuming .006" pistons out of the hole, it's more like 12.1:1 on the 383.

I would probably not run 12.1:1 and a turbo with lots of boost, even with E85. Although I'm thinking of running 11.2:1 on pump gas with methanol. So it may not be the worst idea. You can definitely run higher compression and a lot more timing with E85.

 

Found a post where with 65cc and these pistons they had 11.1to1 Cr. So it's quite possible I did mess up the calculator. And you are correct Jake fusion


So I guess even with 317 heads 72cc and a pretty thick gasket it would barely put me to around 10 to 1 compression. Since 70cc would put me at 10.5to1.

 

Noone else with an option?

 

Swap pistons, balance crank as needed.

 

Why should i swap pistons. As in. Can you give me reasons

 

It was one of the options YOU gave in your first post.

 

To lower the compression...duh

A turbo is a significant investment. If you end up ditching the turbo kit, like many people have done after sinking bunch of money into a forged shortblock, you at least have the option to run the dished piston with the 59cc heads as a strong NA engine until you can get the turbo kit and all the odds and ends that are need to go with it. Then when you get the turbo, just bolt on the cheap 317 heads to get the more boost friendly compression ratio and sell off the 59cc heads.

 

 

Not sure if the pistons deck clearance is right. BUT at .06 it's 9.4:1 compression. With .016 clearance it's around 10.4:1

 

You have to use negative if it's a 3cc valve relief and -.006 out of the hole... but I think Wisecos typically come out around .010" out of the hole (at least Diamonds do).

On E85 you can run 12.1:1 and like 20lbs with 25 degrees of timing. It's insane.

 

okay Jake with that of .010 it's right at 9.9:1 . So that's a good deal right around where I'd like to be.

so I still should be able to reuse my valvetrain set from my 243s so this should work out good. Thanks again