11/06/2003

Nitromethane and Alcohol

Two cheap major fuel sources.  Model Stores - for model boat fuel (
synthetic lubricant, Methanal, 40% Nitromethane blends ) and paint
stores.  Acetone and toluene/xylene are paint thinners, solvents etc
heavily used in painting.  Buy them by the barrel cheap.

Baseline fuel will generally be gasoline.  Track wisdom is to buy the
most expensive highest octane stuff at the track.  Great for the
operators wallets.  

If you can do it economically, buy pump gas and add significant
toluene/xylene to it.  50% does not hurt anything and it will never
knock.  The benzene's burn late and slow.

Guaranteed, the self blending of benzene's will give a better fuel than
the track fuel.  For americans, unless they have a specific limit and
test on toluene or xylene, will not show up on fuel testing. Gasoline
can contain up to 50% aromatic at the pump anyway.

Use of the boat fuel as a boost fuel does need tricks.  Its octane is
probably resultant around pump gas - the nitromethane lowers it and the
alcohol raises it.  But, as I explained earlier, the nitro NO2 portion
forms nitric acid by picking up an OH radical, and forming HNO3.  This
in a near pure nitro motor gives it the smell and burning sensation.
But, this engine will not be near pure.  It will have a lot of late
burning hydrocarbons - letting go about the time the nitric acid breaks
down into oxygen,nitrogen and hydrogen.  

The combination of aroma tics and nitromethane insure a lot high
pressure burn.  If you tweak the timing a tad, when the exhaust valve
opens, it will still be burning and expanding somewhat and the turbine
will get wildly spun up.  

If you wish to blend water with your joy juice, you will need to add
acetone about equally to the water.  Naca papers will give you a clue
about how much water you can inject - but it can easily go well over 1:1
water wght to fuel wght and Naca stopped testing at 1.6 water to fuel.

The acetone evaporates about 10 times faster than alcohol with similar
octane.  These also helps to seriously cool the intake track.  It has a
very low flash point and will help speed the burning of the slower
methanal and nitromethane fuels.

Since you are planning on separate injection of boost fuel, don't get
hung up on jet changes, base mixture changes etc.  Set it up on gasoline
and toluene/xylene and run. 

Once the base is right, just add kickapoo joy juice as needed for
performance. Alcohol, acetone and boat fuel, all have excess
hydrocarbons to their oxygen, so will richen the mixture somewhat when
added - even though they contain significant oxygen.  The nitro methane
portion is a mono propellant rocket fuel and will continue to make
increased power with increased amount right up to engine destruction by
itself.  It will make fantastic heat in conjection with aromatics.

Use the Bruce Tune method.  Don't tune for bring the engine to knock -
retard the timing and increase the fuel somewhat and tune for maximum
boost.  You will be a few percent less efficient but will be burning
twice as much fuel and air this way.  The retard will blow some burning
fuel out the exhaust port into the pipes and as it finishes expanding
will greatly accelerate the turbine.  No need to add afterburner fuel
with a judicious use of retard.

-----------------------------

Thoughts for the insane.  Nitromethane becomes di-nitromethane when
exposed to UV radiation and becomes more entertaining to run.

Purple Nitro - Potassium Permagante KMnO4 mixed into a slurry with
nitromethane.

And once again china hits the hot spot as the new supplier of industrial
nitro-methane.  Cheaper and higher purity.  Reasons not to use it.

Perhaps those looking for more oxygen and not satisfied with the excess
of a turbocharger might start looking at solid fuel rocket propellants.
Opps - I got those on borrow to scan - sorry.  Be a few weeks.