Originally Posted by
homemade wrx
the other downside that people don't realize is that a higher octane fuel, like e85 also is harder to ignite/burn...this requires more fuel to be added to get the same power on a system designed for lower octane. In order for e85 to be beneficial it needs to be run where it desires, LOTS of cylinder pressure compared to your engine designed for 93 octane.
Yes, it also does require a higher mass flow for stoich and therefore more consumption BUT that can be worked around.
I did my entire senior project around a 250cc 4-cylinder 4 stroke for Formula SAE....AUTO-x'ing
It was 11.5:1 and turbocharged at 18 psi...so when I say it needs cylinder pressure, I think you get the idea. 13:1 CR and e85 would be a pretty nice DD setup and very efficient as well.
as for ethanol production, leaps and bounds have been taken in new forms of by-product and waste, instead of corn...
I will stop now as I can ramble on and on about it. Take a year and half to design your senior project engine basing around direct injection ethanol and...
This is something I was arguing with some friends and some people on the board a while back. I argued that while it has a lower energy density its other properties would allow an engine designed to run on ethanol to largely close the gap in efficiency with gasoline engines. A high compression engine tuned specifically to run on E85 should be much closer to gas engine fuel consumption than these compromise "flex-fuel" engines we are dealing with today. Does all of this check out with what you found in building your engine? I'd be interested in hearing what somebody with practical experience has to say on the subject.
