What would be the most compression a guy could run on E85 with out haveing to make compromises like retarding the timing? this would be a 4000 pound street car with 3.54 or 3.73 gears with a Passon 20% overdrive gear in the 4 speed. Specs on the motor:

484 Hemi 4.310 bore x 4.15 stroke
ported iron heads
hydraulic roller cam 226/230 at 542 lift 112 lobe centers
Inline street Hemi intake with AFBs
exhaust manifolds and 2.5" exhaust

Thanks, Joel

Back when I did my conversion, the research that I did showed that 15:1 was very doable. My 11:1 was considered to be on the low side to take advantage of the octane rating of E-85. My first time down the track with E-85 was within .1 of my very best time on pump gas with no timing change.

What is the octane rating for E85? Did you have to rejet for it?

WOw, 15 to one is really up there. I don't think I want to go that high. What is the octane rating of E-85

THanks,Joel

where can I find more info about converting an old carburated engine over to E-85?
a quick search of the board only turned up this thread

thanks

I know 15.9-1 has been sucessfully done in a 654ci hemi on E-85. Joel I wouldn't be a bit afraid to try 12.5-13.5-1.
E-85 is rated at 105 octane but has different burn characteristics than gasoline. You also get the cooling effect than alcohol provides. When I ran it in my 440 right after startup, often times my intake manifold would be sweating. Operating temps were about 15-20 degrees cooler than on gasoline. Dave

Thanks Dave. I think I have most of the parts on hand to assemble a 12.8 to 1 motor. I didn't know if I should use a thicker head gasket to drop the squeeze down a bit. Sounds like I should put it together at 12.8.

I believe one of the magazines supercharged a 13:1 big block chevy on E-85 and it didn't have detonation problems.

R.

I learned a lot from the info at www.E85forum.com. Lots of good stuff there to help make the right decissions.