Well that is true if you are running lean but ANY aircraft engine running
full power
full rich for takeoff or top speed is .60 to .65 BSFC. Tracy Crook's
engine burns
20 gallons an hour during the Sun 100 Race. That would be 120 pounds an
hour. Divided
by .6 is 200 HP. About right for a low power RX8 engine with only four
ports
available rather than the six ports in the high power RX8 engine version.

Notice the dual HP and torque curves for this Mazda p-port four rotor
Lemans engine.
The curves are labeled  power and efficiency. I have applied Aubrey's
conversion
to the Lemans engine efficiency  BSFC curves. The BSFC curve for high
power configuration is
missing. No telling what it was and I don't think Mazda wants you to know
:)

Jarrett & Heidi Johnson wrote:

Paul, just for the record. I was reading some old emails and noted that
Tracy said he ran it lean of peak even when racing. This would lead me to
think that he's making even more power  [assuming a BSFC of 0.48-.50]
120/0.50=240 Hp Has anyone compared the offical speed around the course to
Rv's chart showing power req'd for that speed?

Just curious.

Jarrett Johnson

I don't recall that. Do you have the message?
Tracy sent me email a few days ago saying 30 pound injectors were not big
enough for 250 HP.

Most people that race in the Sun 100 soup up their aircraft engines and
they run them at well over 3000 RPM. Props are cut down or repitched.
There is a company here in SoCal called LyCon that specializes in souping up
aircraft engines for racing purposes. For that reason it is hard to correlate
Sun 100 speeds with HP.

Paul Lamar

 " I run lean of peak even for takeoff unless I have a short runway with obstacles to clear.  So far, I even race LOP.  I was 3 GPH lean of best power setting during last year's Sun 100.

On those rare occasions when I use it, I don't rely on a mixture monitor or EGTs for maximum power setting.  If you have ever run a model airplane engine you are familiar with what I do.  I twist
the EC2 mixture control and listen for maximum rev point.  Nothing is more accurate, faster (or easier).

Tracy  (EM2 fuel flow calibrated in $ per hour)"

Paul above is a direct plagerization off the other list. I don't know what 3gph equates to in BSFC but thats pretty good power if its lean of peak.  This would be [ I'm assuming] with his old set
up using the 13B, not the Renisis.

Jarrett Johnson

Well then it must be 23 gallons per hour and .65 at peak power. Since he was sand bagging 
in the last Sun 100 it cost him $500 dollars minus the $3 dollars he saved on gas
as he missed winning the Everett Hatch Memorial prize by 3 MPH. He needed 220 MPH and 
he went only 217 MPH. This year he should easily win $750 if John Slade does not enter.

My guess is .65 BSFC at 23 gallons an hour or or 212 HP. OK Tracy what are the real numbers? 

What Klause does in long cross country races is plot MPG so he can go just fast enough 
to make his destination with out a fuel stop.
 
Paul Lamar
 
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