A study of the Wright Whirlwind 200 hp J5 made me wonder if it could be matched to a Cessna 172 airframe.
Radials have the ability to run on much lower grade 50 octane gasoline and have great air-cooled reliability. The J5 can generate 200 hp at less than 2000 rpm.
But it was found these these engines burned far more oil than the Continental or Lycoming ones, with oil/fuel consumption ratios approaching that of 2 cycle mixtures.
For all the desire to save weight, the Spirit of St. Louis would have had to carry a considerable amount of oil to make the trip.
How much oil did Lindbergh take along, and where was it stored in the plane?