Most B-17 vets I've spoken to haven't made big distinctions between the
Wright R-1820s and the Studebaker license built versions, though one
characterized the latter as "notorious oil throwers." When one considers
how many of these engines were mass-produced, it's amazing there weren't
more problems with the R-1820s. See
http://www.t6srus.net/t6modeling/wri...1820%20engines,
and compare the notorious R-3350, which was rushed into production without
full development and which killed many people in B-29s.

I looked at some production nos. and it appears Studemaked built 63,000
R-1820s during the war.
http://www.thoroughbred-cars.com/car...%20History.htm
I think they outbuilt Wright Aero in the total no. of engines built for
B-17 usage during the war.

The design was inherently "leaky" and "dirty" in operation, I believe,
though it was probably the best Curtiss-Wright product of the War (possible
exception, the P-40).

Brian