(fwd) Chemical warfare

[Robert Harris]

First some heresy. Heat has little directly to do with making power. Pressure
is the only thing that matters.  A thousand psi of supercold nitrogen gas will
shove the piston down just as hard and fast as a thousand psi of 2000 degree
air/fuel.  Heat exists solely to raise the **** Pressure **** of a gas.
Consider that 1500 psi peak pressure on an engine is considered very good -
yet water at ~705 f makes ~ 3206 PSI (steam tables greg :-) )   Since burning
a pound of gasoline yields about two pounds of water ( where do you think all
the hydrogen goes??)  and the pressure contribution of water is at least 3206
psi - do you think all that nitrogen and carbon monoxide/dioxide stuff might
simply be diluting the pressure /power ( ME's - remember the term Brake Mean
Effective Pressure - and where does it consider temperature )

That said, there are two easy ways to make more pressure.  More "heat" which
raises the temperature of the working gas, which in turn raises the pressure
the piston sees and by adding molar product ( molecules ) to the working gas.
You raise power by adding more of either or both.

Which brings us to chemical warfare and multi fuel systems.  Two general types
- Dual Fuel ( A OR B but not both) or BI Fuel ( A AND sometimes B).  Need to
get definitions up front in this era of Klintonesque redefine language to mean
what I need it to mean to cover my arse - text book ones no longer matter.

Rules permitting - selection of the second fuel.

Enter Rocket Fuel Monopropellents.  Mono propellants have this interesting
characteristic that they need nothing other than themselves to burn - usually
highly exothermically, rather fast and violently and with largish amounts of
molar product.  The intake tract serves simply to convey these liquids to the
cylinder.  Power is limited by hydrolocking the cylinder at just past TDC -
who needs any silly air. - Oh and by mechanical strength - can't launch the
heads into orbit without clearance from NASA.

There is absolutely no way to get more power out of any given engine than by
"hydrolocking" it on rocket fuel.  There physically is not room to add more
fuel.  Remember 100% fuel - no air.

Given that the physical and mechanical strength of an engine is to be built to
live at the chosen power levels, the major choice is how much power to build
into the mechanical portion and how much from the chemical portion.  Bumping
the boost vs tipping the can so to speak.

Reasonably available Rocket Fuel liquid monopropellants - there are  two and
they are mutually antagonistic. Nitromethane and Hydrazine.   Either, once
ignited will burn without the presence of any other chemical.  Either generate
enormous amounts of heat, and product.  Either are/have been used to throw
largish rockets out of this world.

Nitro is available at your local model shop.  The question to resolve now is
how much power do I wish to make chemically vs mechanically. If you are going
to the trouble of a bi fuel system you may as well go for it. Your are paying
the weight and defecation complication factor.  Either way, everything but the
induction will be the same for the same amount of power. No magic way to make
a bottom end hold up without building it to hold up.

To the baseline fuel air mixture adding nitro increases power at about the
same percentage as nitro to baseline.  So, if you are looking for 50%, hold
the baseline fuel air the same as stoic, add half the amount of fuel as Nitro,
and now you are up 50%.  Stoic on nitro is 1.7 to 1,  best power at 1 to 1
fuel to air weight.  

As you add nitro, you lower octane, so the conventional way is to add methanol
to recover some of the octane and to cool off the combustion.  Its stoic is
about 6.5 to 1 and best power around 4 to 1.  As you add alcohol, you can back
off nitro.  Two units of alcohol replaces 1 unit of nitro.  A minimum of 10%
should be acetone - stoic about 9.5 to 1.   Its high octane about 120 or so
and has an extreme affinity for water - eliminates phase separation.  Its
flash point is also lower than alcohols so it helps igniting the nitro and
alcohol portion.  As a side note, as long as you keep increasing the acetone
level ( and its not a bad thing ) you can add water to the mixture and avoid
separation.

As for hydrazine - now I am completely out in never never land and the
following is anally extracted and is only where I am thinking of going.  First
thing to note is that hydrazine is hygroscopic and completely miscible in
water.  That makes H2O the base solvent for this stew.  

***** WARNING - SECRET CHEMICAL INGREDIANT ****** 
Hazardous to mental health - you may have been lied to.
Alpha-Picoline C6H7N  Benzene ring with a nitrogen substitution.  BP 129 C,
Flash at 28C.  density .943 - miscible with water in all proportions, MSDS is
rather mild.  
                                                    Critical Compression Ratio
                    Research    Motor       600     600    2000   2000  RPM
                        Octane   Octane     212     350      212     350  Temp

Alpha-Picoline      131         112     12.7    11.0     14.2      9.2
Toluene               124         112     15.0    11.35   13.5      9.0

One of several high octane non fuel water soluble discussed in "Knocking
Characteristics of Pure Hydrocarbons - API project 45 1958".  Critical
compression ratio is the ratio required to induce knocking at the cooling
jacket temp/rpm specified.  Just a tad more usable than "Octane"

If this is reasonably available - looks like the octane improver of choice for
a water based blend.

(Side note for painters.  Grow 1500 lacquer thinner is Toluene, Acetone,
Methanol and VM&P Naptha - sounds like about 110+ octane racing fuel blend to
me.)

But I don't intend to use water as the solvent.  I am seriously considering
industrial strength ammonia cleaner ( 30% NH3 by weight in water).  Ammonia
has a lot more heat absorbing capability than alcohol, has more heat energy, a
much higher auto ignition temp ( 640c) and blends well with hydrazine and
water.

And definitely lubricant - see previous rant. Acetone is always an option.  If
forced to dry this out, methanol will work, but I've developed an unnatural
interest in the 120 octane range food grade chemicals Methyl, Ethyl, Butyl
Acetates as they are highly miscible in water and alcohol.  For oxiderizer
additive - there is always glacial acetic acid - very high percentage oxygen
and blends well.  

Now the choice is how much chemical vs mechanical.  Keep in mind that with
enough chemical - the induction doesn't matter - air only "pollutes" Rocket
Fuel - yes I know that air allows a more complete combustion - better
efficiency - but at a cost of potential power - oops nothing produced is
strong enough to take ignition at hydrolock anyway so may as well pollute it
with air.

With enough chemical, the induction /valve train loses a lot of significance.
The exhaust is always critical.  Take a pushrod V-6 say buick.  With twin
turbos, EFI, intercoolers, water/alcohol injection - 750+ hp is achievable.
But, you don't even have to do much more than injection to get this on
straight nitro.   A streetable compromise might be about 300 from a mild turbo
and street gas, with a second EFI progressively bringing on the joy juice as
the throttle went down.  Now you wander the streets as a mild mannered Clark
Kent, awaiting the opportunity to pop some spinach - whoops wrong guy - and
whip up on Bluto.  And you don't have 5 grand plus in the induction system. 

Any portion of the power assigned to chemical is not there untilled needed.
This can mean a lot in drivablity and overall economy - even if the chemical
costs 50 bucks a gallon.



The Luddites were RIGHT!!

Habaneros - not just for breakfast anymore