DB-601N reliability issues

[mack8]

Hope this is not duplicating another discussion, but i have found one of Mr Calum Douglas's fascinating webinars, and among others he spoke about the DB-601N oil diluting problem with subsequent bearings failure due to the use of C3 fuel (instead of the C2 fuel for which the engine was designed) which wasn't evaporating and entering the oil circuit. My question is how did they solved this problem? As i understand there was a significant number of Bf-109F-1/2s and Me-110 variants using this engine. I need to read more, but presumably they started by derating it (like they did many times with many engines/variants)? The 1,35 ata figure refers to the derated engine, with 1,42 ata being the fully rated figure? Were the N engines ever cleared for 1,42 ata and if so, when?

Thank you.

 

[z42]

From reading Mr Douglas book it seems the solution was essentially to go back to the lower compression DB601E, bore out the cylinders a little, thus creating the DB605, running on B4 fuel. DB601N was withdrawn from service, and while waiting for this withdrawal TBO was drastically reduced. Later in 1943 the distillation curve of C3 was changed, but too late for the DB601N though apparently some later variants of the DB605 were able to use it. Mostly the very limited quantities of C3 was reserved for the BMW801 which really needed it, and being a radial engine ran much hotter and thus didn't have an issue with oil dilution.

 

[Crimea_River]

Calum posts here occasionaly as D Deleted member 68059 so maybe he will stop by. I must admit that I have not got to this point in his book yet as other things have intervened.