Doug,
I have been rereading your e-mail from 7/17/2008 and can't quite get to
grips with your figures.
Are you saying that 18 lbs/hr ( 3 gal/m)  / 10.5 = 189cc/min, /5 =
37.8hp is for cruise or 37.8 x 4 = 151.2hp is for cruise.
So the 18 lbs/hr is for each injector?
Is cruise 6,000 rpm
If that is correct than 151.2 hp for cruise at 6,000 rpm is 200hp at
8,000 rpm for WOT . Or are you at about 180 hp at 7,200 or 190hp at 7,500.
I just can't seem to get to grips with this.
George ( down under)

George,

Thanks for catching the math mistake.  Let me try again.  At 6K rpm and
5 BSFC my P-ported engine would be putting out about 200 hp. and
burning 100 lbs  of gasoline per hour.  Divide by four and that is 25
lbs per hour per injector.  This is a fuel burn of 16.6 gal./hour. Note
these are guesstimates.  The BSFC and fuel burn had better be lower in
real operation or I will be swimming home:)

For 300 hp (8k rpm) with a 2psi  boost on ethanol, I calculated at  0.75
BSFC. That is 35 gallon/hour.   E -90  ethanol is a heavier fuel at 6.4
lbs per gallon so it skews the BSFC calculations to appear better than
it is IF you are used to thinking in terms of gasoline.  The injectors
are rated assuming the weight of gasoline is 6 lbs/ per gallon  but they
don`t meter mass they meter volume or cubic centimers. To arrive at the
0.75 BSFC at max. power settings I calculated 1.25 times the quantity of
gasoline  needed for a Lycoming enigine at those power settings.
Yes, rough but  the advantages of E-90 depend on deck pressure,
operating altitude, injector location, and manifold system design.

Doug


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