Inaccurate performance data for BOB fighters in COD comparing to RL data

[lane]

Originally Posted by ATAG_Snapper

Thanks, Lane, that's a handy chart to have on file!

Your welcome ATAG Snapper, I'm glad you too found that chart handy.

Looking at A. R. Ogston's excerpt from History of Aircraft Lubricants (Society of Automotive Engineers, Inc. Warrendale, PA USA), p. 12.


Of particular interest to us is the passage: "The Royal Air Force had used 87 octane fuel until March 1940 when Fighter Command converted all its Spitfire and Hurricane Rolls-Royce Merlin powered fighters to 100 octane (i.e., Grade 100/130). This permitted the maximum manifold pressure of the Merlin II and III engines of the Spitfire, Hurricane and Defiant fighters to be raised from 42 ins. Hg to 54 ins. Hg which gave a 30% power increase, that is from 1,000 to 1,310 h.p.

We can see in the table Equivalent Boost Pressures in Different Units above that 42 ins Hg is equivalent to +6 lbs/sq.in boost and 54 ins. Hg is equivalent to +12 lbs./sq.in. Therefore we can see of course that Ogston is in agreement with Schlaifer's Development of Aircraft Engines and Harvey-Bailey's, The Merlin in Perspective posted earlier.