Hi Knegel,
>dod someone know the differents between this two engines and when the Aa got introduced??
The DB601A-1 came with two different superchargers, the old version with 4.0 km full throttle height and the new version with 4.5 km full throttle height.
During the attack on France, the old version was definitely in use as the French captured a Me 109E-3 equipped with it.
During the Battle of Britain, the new version was definitely in use in the Me 110 and Me 109 as the British had captured one example of the former equipped with the new type, and re-fitted the captured French Me 109E (which had been transferred into British hands) with a new type supercharger as well.
I suspect both versions were used alongside each other for a while, but I have no idea of when the change-over began and when it was finished.
The DB601Aa apparently was produced alongside the DB601A-1 even before the war began. Butch's research indicates that about one third of the engines produced (if I remember correctly) were DB601Aa and two thirds DB601A-1. (Best ask Butch directly for details.)
Technically, the DB601Aa differs by allowing operation at higher boost pressures, yielding more power. What I only realized due to Elkaskone's recent posts is that the DB601Aa seems to have had a supercharger equivalent to the DB601A-1 (4.5 km) from the beginning, or that the power table and the power graph is describing the capabilities with the 4.5 km full throttle height supercharger.
To round off the discussion, the DB601N was introduced just before the Battle of Britain and equipped one Gruppe of JG 26 during the battle. The engine was quite a bit more powerful than the DB601A-1 and Aa, but it was only available in large numbers after the battle had ended. (Originally, the Zerstörer units hab been scheduled for priority conversion to the new engine, but when they proved worthless as escort fighters, the Me 109 got priority instead.)
Regards,
Henning (HoHun)
