Alcohol/M85 with a twang.

Seth Allen n9540517 at cc.wwu.edu
Mon May 19 05:30:39 GMT 1997


On Sun, 18 May 1997, Robert Harris wrote:

> Date: Sun, 18 May 1997 00:46:12 -0700
> From: Robert Harris <bob at bobthecomputerguy.com>
> To: diy_efi at coulomb.eng.ohio-state.edu
> Subject: Alcohol/M85 with a twang.
> 
> Friend of mine has one of these little remote control helicopters
> Showed me his "Fuel" .  16 % Synthetic Castor Oil, 69 % 
> Methanol Alcohol, 15 % Nitromethane.  Sort of sounds like
> M85 with a twang. Was sort of expensive - about $14 a gallon 
> until you figure that Nitro runs 50+ a gallon and ain't too 
> readily available and this stuff is available at any model airplane
> shop, in various mixtures and proofs. 
> 
> Now, since Nitro and Alcohol both have high latent heats of
> evaporation - i.e. makes air fuel real cool, and this blend probably
> has reasonable octane, what do you suppose would happen if
> a reasonable amount was separately injected as boost went positive?
> 
> You think it might be an inexpensive way to get things real exciting?
> If the first ingredient ain't Habanero, then the rest don't matter.
> Robert Harris <bob at bobthecomputerguy.com>
> 


While researching methanol as a fuel for my staged injection turbo 
project, I stubled across a SAE paper dealing with benzene, methanol, 
tolulene, nitopropane, and nitromethane.  Hydrazine and nitromethane in 
particular are mono propellants- they do  not require air to combust. 
Typically the pressure rise is so rapid with these fuels, that engines 
don't last long. 0.5% hydrazine in methanol was quoted as giving marginal 
engine life. Nitromethane was similar, although at much higher 
concentrations.  Nitromethane it appeared, had a very low octane, 
although I cannot remember if it was evaluated as a straight run fuel. 
The methanol has a high octane equivalent, and due to the tendency of 
nitro to compression ignite (like diesel) and the susceptiblilty of 
methanol to catalytic ignition with platinum, would explain the 
ignitionless running of model airplanes on nitromethane and methanol.  I 
thought nitro was high octane, until I looked into it.  It would probably 
pop my turbo motor first shot.  

-Seth Allen



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