On Sun, 29 Mar 2009 00:44:22 -0700 (PDT), Bob Hoover
wrote:




Three gallons of fuel is about 18 pounds One of the most critical
specifications for an engine is its Specific Fuel Consumption, which
is how many POUNDS of fuel it burns PER HOUR to produce ONE
horsepower. Normally aspirated air-cooled engines are clustered near
the .500 mark, meaning they burn about half a pound of fuel per hour
for each horsepower. Economy of scale applies so you'll find a big
radial down near the bottom of the curve and your lawn-mower up near
the top, but your flying Volkswagen will be found clustered with the
small (ie less than 500cid) Lycomings and Continentals.


just recently I came across the fuel consumption figures for the
English Pobjoy Niagra radial of the mid 1930's.
it was quoted in those wierd english dimensions of lbs/hp/hour.
converting the figures into the litres per hour I use and corrected
for horsepower differences the Pobjoy Niagra radial has exactly the
same fuel burn efficiency as the Continental O-200.

Stealth Pilot