109 e3b against spitfire II

[Seadog]

Originally Posted by Crumpp

The document compares the operational engines at the time it was prepared. At 17500 feet, the document is correct in the power output of a Merlin XX at it's approved Emergency Power rating of +9lbs at the time the engine were compared. It is also correct in its assessment of the DB601N series.

It is not correct in its math of the power to weight ratio of the engines. The Merlin XX is the same as the DB601N.

In Nov 1940 the operational limits of the Merlin XX were 12lb/3000rpm TO = 1280hp, and 12lb/3000rpm @8500ft = ~1360hp in MS gear. Operation of the boost cutout would give ~14lb in FS gear, but I don't know exactly when official approval was given, however this capability was present in all Merlin XX engines.

At 1280hp and 1450lb weight gives lbs/hp = 1.13 but I agree that the values given in the chart were confusing.