Ethanol

Has anyone heard of good/bad experiences using ethanol instead of methanol in a roots/screw funny car type motor?

 

I believe Mark Thomas ran/runs ethanol in his IHRA TAFC and he's done pretty well!!

 

ethanol vs. methanol

Yes, Mark runs straight ethanol and was an IHRA champ many times.

There is discussion about ethanol in our "5000 HP on Methanol" book and air to fuel ratio info in our fuel injection book. Basically you have to run about 40 to 45% less fuel volume than methanol. If you are fuel injected, you need to reduce your engine nozzle area about 40 to 45% and increase your bypass area about 40 to 45% to keep the same system pressure; or reduce your fuel pump size / volume by 40 to 45% and you total jet area about 40 to 45% at the same ratio of engine to bypass areas.

Unfortunately that rule of thumb may not work from methanol tune-ups that are way out there. Some depend on high cooling from higher methanol volumes (than others) to retard detonation or pre-ignition. Those would be setups with a lot of spark advance, very high boost, a lot of manifold heating from late fuel introduction into the air stream.

Ethanol simply does not have the fuel volume to cool the incoming mixture that methanol has due to the reduced volume.

From a fuels application standpoint, it should work quite well. However, you may need to back down on the fuel volume with care. We have seen a 25% spread in air to fuel ratios from different methanol engine tune-ups on similar engines. Conversion to ethanol on these various engines may end up in different settings. Certainly different lean down percentages.

One final note, it is all about air to fuel ratio. Once you find the value, it seems to be rock solid. You adjust for air density and the plugs always read the same.

Bob Szabo, author of "5000 HP on Methanol" and "Fuel Injection Racing Secrets"
www.racecarbook.com
(707) 446 2917

 

Here is what I am wondering......
Assume two identical motor/blower combos. Same long block in both cases. Tune one for optimal meth performance. Tune the other for optimal eth performance.
What differences would result?
What if the mechanicals of the second were then further altered to best favour ethanol. Then what would result?

 

I don't want to bust anyones chops here. Mark DOES NOT run Ethanol! Not that he wouldn't and he has "played" with it as have we, but it won't pass fuel check in IHRA or NHRA. We will see what IHRA has us running next year