E85

[kel]

I like these biofuels and I really believe they are the race fuels of the future.

So I decided to dyno the bike to compare Avgas and E85.
My bike is a 125 air cooled 2 stroke running 13:1 compression. We changed main jets and altered the igniton timing between the two fuels, nothing else was changed (except the fowled spark plug)
The results, well E85 was the winner by .2hp. I expected an increase in torque lower in the power range, if there was any it was minimal. E85 runs much richer than Avgas, my main jet jumped from 110 to 145 (power jet requirement didnt change). E85 runs cooler than Avgas but that wasn't obvious on the dyno. I had expected a shift in the power curve between the two fuels as the pipe would react to the change in temp, seems I got this wrong. The Avgas pulled 30 odd runs never dropping below 26.5hp on E85 the power did drop. Neal mentioned E85 goes lean as the motor heats up, would seem he was right. So you'd have to sacrifice a touch of top end and run E85 rich to keep the output stable, from what Ive read you can get away with a rich mixture much better than with Avgas.
The bike developed a miss at 11.5k which was making a mess of the graphs but I'll get TZ to pull out a decent overlay when he has time.

So the verdict - I like E85 for all the reasons I've stated before and would use it in a heart beat if it was legal.
I still need to get the bike dialed in properly on Avgas , once thats done I plan to try E10.

[Moooools]

Conclusive results on race proven bikes over a wide sample size. Especially liked the bit where you designed an engine to run on E85.
There is so much data you may just have to give us a spread sheet so we can take it all in.

Can't see how anybody could pick a hole in that testing.

[Henk]

Mools, stay out of this or I will tell the world you confided in me that you are running nitromethane.

[kel]

Can't see how anybody could pick a hole in that testing.

Ooh the sarcastic reply without the stupid question. Obviously your own format is open to interpretation.
Sorry but I missed the part were I suggested this was any kind of conclusive test. Silly me, thought I was quite clear in regard to the limited parameters.
Please enlighten us mere amateurs on the fundamentals of engine design and the extensive test parameters that should be considered for an hour and a half on the dyno.

[Moooools]

Ooh the sarcastic reply without the stupid question. Obviously your own format is open to interpretation.
Sorry but I missed the part were I suggested this was any kind of conclusive test. Silly me, thought I was quite clear in regard to the limited parameters.
Please enlighten us mere amateurs on the fundamentals of engine design and the extensive test parameters that should be considered for an hour and a half on the dyno.

Only taking the piss mate. Mostly...

I think the purpose of the thread is pretty clear: The difference in performance between E85 and current rules compliant fuels.
I think the main parameter that should be looked at for an hour and a half of dyno testing is the inability to draw any conclusions.

Fundamentals of engine design? Use some steel for the whirly bits and some aluminium for the shaky bits and make it spark every fourth stroke. Any more than that and they wear out to quickly.

[Moooools]

Mools, stay out of this or I will tell the world you confided in me that you are running nitromethane.

Hey now. I only run that in the chev V8 I have running my supercharger. The rules don't restrict fuels for auxiliary engines.

[F5 Dave]

Max you forgot; Scientific studies have shown. . . "

[TZ350]

I'll get TZ to pull out a decent overlay when he has time.

Blue line Av Gas, Red line E85, both jetted as best we could.

Later the engine developed a miss at 11,500 on Av Gas, not sure what that is about yet.

Without the miss I am sure we could have got the Av Gas to match the E85 for over rev.