[vanir]

Knowing that the DB601N used in the Bf109E isnt drastically different to the earlier DB601A-1 and Aa both in structure and operation, only making use of higher octane fuel and thus higher compression, boost pressure and RPMs I find it rather odd that the 601N should behave any bit differently to the A!?

Do you have any more info on this and its supposed cause?

I've heard the same thing about license produced 601A engines in the Macchi, this was apparently due to the Italian version being "too finely hand finished" for the environment (afaik they did have sand filters). The commentator, the aircraft historian who wrote Clash of Wings said "if the Hurricane was a Ford, the MC.202 was a Ferrari and had a very high unserviceability rate in North Africa."

Now this is a pretty thin comparison I know, but I was thinking the 601N motor was the one that was finely tuned by Germans. It was a high maintenance engine like the Alfa version of the 601A apparently was. Though quite well made perhaps they just didn't like rough field conditions very much, where parts supplies were in constant shortage and available fuel quality might be questionable. You wouldn't take a hammer to a 601N running rough and expect to fix it, but you might to a Kittyhawk.

Just a thought.