BMW 801D v.s 801D-2 What is the difference?

[Luft.4]

Hello all, I have tired to find the exact differences between these two engines but am having difficulty. Would anyone have more information on what the exact differences are, and when the D-2 engine came about? Any help is appreciated.

All the best,

Dan.

 

[mack8]

There are other much more knowledgeable engine folks here, but according to german wiki the BMW-801D (no number) was a project for a single stage 3-speed engine running on B4 fuel. Presumably then abandoned in favour of the C3 running D-2 (which required much fewer changes compared to the 801C model) which had modified supercharger ratios (but still 2-speed like the 801C).

 

[tomo pauk]

There are other much more knowledgeable engine folks here, but according to german wiki the BMW-801D (no number) was a project for a single stage 3-speed engine running on B4 fuel. Presumably then abandoned in favour of the C3 running D-2 (which required much fewer changes compared to the 801C model) which had modified supercharger ratios (but still 2-speed like the 801C).

FW docs note the BMW 801L with - at least going by the power curve - a 3-speed S/C, whose power was eventually in the ballpark with what the fully rated 801D eventually (after late 1942) was developing.
I'm not sure that such the 801L ever flew, the designation was later used on different 801A and 801D installations..