alky/water inj

[Shawn B]

Swiped from my Buick list was this lengthy post (minus the contact info)
the goofy thing is that this was posted just today!

start
Subject: Water/alcohol injection

I thought I would give my experiences with water/alcohol injection. 
First, 
lets clarify a few things.  Water/alcohol injection is known in the
aviation 
industry as "ADI"  Anti Detonate Injection.  I have been useing building
ADI 
for many years on both aircraft engines and racing engines.  I use to
build 
2,240 cid Rolls-Royce Griffon engines for unlimited hydroplanes.  We use
to 
run a factory liquid to air aftercooler AND liquid intercooler (the 
intercooler is a water jacket that surrounds the two stage
superchager).  But 
when the engine would backfire, it would sometimes rupture the
aftercooler 
core.  In a fresh water course, the added water induced into the intake 
system was OK, BUT in a salt water course.............salt water
injection is 
NOT very good.  So we decided to remove the aftercooler (besides, we
were 
running out of aftercoolers seeing how the engines weren't produced
after the 
late '40s) and increase the ADI quantity.  In a 8 minute race we would 
consume 70 gallons of 115/145 AV gas with an additive in it, 25 gallons
of 
50/50 water/methanol, 130 lbs of nitrous oxide, and approx. 5 gals. of
oil.  
We were running the engine at 4,200 RPM (calculate THAT piston velocity 
considering a 6.50" stroke and a 6.00" bore x 12) at 130 in/hg (in/hg is 
inches in mercury....approx 35+psi boost ..depending on atmospheric 
conditions)  Detonation was and is always a problem at high boost
levels.  By 
removing the aftercooler we had more power due to increased airflow. We
just 
replaced the aftercooler with a 6.00" inlet pipe from the superchager to
the 
intake log/manifold.
   Back in 1989 I used ADI injection on my GN, and could use a Conley
Mag4 
race chip on 92 octane with no intercooler (I removed it to verify 
intercooler efficiency) and NO detonation.  I have tuned a friends 87
T-Type 
to a 11.51 @ 117 on 92 octane pump gas, with a highly modified Jay
Carter 
water/alcohol system.  He was running 21-22 psi boost, ported heads,
stock 
I/C, 2800 lock-up converter, DOT's, 202 cam, TE-44 turbo, with "blue
tops", 
THDP, and through FOUR (4)mufflers.  His car would run this with out
doing 
ANYTHING to the car from the way it was run everyday on the street.
    ADI works by first reducing intake temps because of the latent heat
value 
of the water and the alcohol.  Methanol has 10 times the latent heat
value of 
gasoline.  And the steam that is created in the combustion chambers acts
as a 
shock absorber to reduce tendencies to detonate.  ADI has been around
since 
the early thirties.  ADI has even been used in early jet aircraft (707's
and 
B-52's for example).  ADI has to be understood to get the best results
from 
it.  It has to be tuned to your combination of parts and to the fuel
curve of 
the system.  On the street it can't be beat.  At the track I would still 
recommend VP C-16 and a good intercooler because there are less things
to 
cause problems.  It does take a bit of tuning to accurately use ADI. 
Just 
think of it as ADI and NOT a power adder.  It suppresses detonation.
PERIOD.  
The friends T-Type used straight methanol and no water because the blue
tops 
were too small for the car, so we used methanol as fuel enrichment AND
ADI.
stop

Shawn
GNandGS at feist.com
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