Russell Kent wrote:

Paul wrote:

Where ever I go and the subject of aircraft engines comes up I
am always amazed at the mis-information out there. Next year
I am thinking of offering a forum at OSH on engine fundamentals.
The first thing I think I will do is pass out a quiz.

[snip]

Can anyone think of any other questions I can ask?

My hangar neighbor says he's getting 180 HP on 4.2 gal/hr.  How can I
prove he's full of it?

Russell Kent

Well tell him the best aircooled aircraft engines in the world
burn .45 pounds of fuel per HP, per hour. Period! No if ands or buts.

Gasoline weighs about six pounds per gallon so he is using 25.2 pounds
per hour. His engine is generating 25.2/0.45 or about 56 HP!!! at that
fuel burn like it or not. He must be gliding.

Paul Lamar

"Castle, Ron" wrote:

Your Friend can still be right. He might have an engine that can produce
180 HP and still get 4.2 gal per hour. An engine say a Lycoming puts out 150
hp O-320. It normally gets about 7.5 to 9.0 gal an hour. Why?
Because the plane is never using the full 150hp at all times. It really only
being used at 90 to 110 for the most part. Same as your friend, he's
configuration only needs 4.2 gals worth of hp to do his flying.
   Ron Castle
   Lockheed Skunk Works

Thats why I said "at that fuel burn" and "He must be gliding." :-)

Paul Lamar
 
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