Max compression for pump gas

Newman434

Weekend Racer
Nov 14, 2005
67
0
0
Orlando, FL
I'm trying to see how close to the limit I'am on compression in my SBC
I want to run 93 octane without having race fuel to drive around and the compression ratio calculators have me wondering
I have :
4.115 bore
4.0 stroke
70cc heads (aluminum)
0 deck height
.040 headgasket
flattop piston but could prob dish some CC's out of them.
I think I'm at like 11.39:1 what is the safe limit?

Do I need to change my pistons to get this engine on pump gas? Please help
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
11.3 with aluminum heads, shouldn't be a big problem with good chambers & a decent tune. 11.5, you're starting to push it...

Tommy
 

MalibuRacing.com Gear

Stickers & Shirts!!