12:1 compression/ High Boost / E85
LS1Tech Sponsor
Joined: Feb 2008
Posts: 300
Likes: 18
Scotty PG is right. Commonly done in restricted classes. Compression can go higher even, but it's typically done with dialed in valve relief depths to raise the pocket away from the ring groove.
__________________
yes, that's actually one of the main reasons I got rid of my last Wiseco pistons and went with custom diamond Billet pistons instead. The valve relief protruded into the top land/ Crown of the piston and after doing some research, I found out that specific area was a cause of high failure with those pistons, I am much more happy with the Diamond piston design, pretty much a flat top with a "slight relief".... At this point I was planning on altering compression by changing Combustion chamber size as I was planning on ordering the HIP'd version of the trickflow 245 heads in the next couple weeks. I originally wanted to do a dual fuel setup E85 on the street and M5 Alky At the track but I was wanting to run both fuel systems with a Split fuel tank ( 20 gallons of E85/ 5 gallons of ALKY) on a Cam driven Waterman 20gph mechanical pump.... which I sadly found out was not possible due to fuel contamination.. id rather not fool with any electric pumps.. atleast if I wanted to put the truck on Alky I have more than enough fuel system to do so.. just would need an extra set of injectors. I want to do drag week with this build more than anything though..so street driving is a must. Id probably have it turned down to 1500rwhp max anyway on the street. so im wondering how much compression I could get away with on the street trim..
Bump. I guess the real question is.. is there a limit to how much Cranking compression your engine sees? 12:1 would put me around 200-208 psi Cranking. I don’t EVER plan on running 93 octane through this engine. It’ll be e85 24/7 or in the future it may see M1
