View Single Post
  #6  
Old 08-29-2012, 11:41 AM
Kurfürst Kurfürst is offline
Approved Member
 
Join Date: Oct 2007
Posts: 705
Default

Quote:
Originally Posted by bongodriver View Post
the 5 minute limit 'has' to be a guaranteed absolute minimum in order to be an allowed limit, the likelyhood of failure 'at' 5 minutes is low and increases proportionally with time beyond the 5 minutes, I don't care if the failure rate is 100% at 6 minutes it's just highly unrealistic to have guaranteed failure at 5:01.
I agree, I am pretty sure the Merlin could operate well beyond 5 minutes at maximum power, if the prescribed temperature limits are also observed at the same time. After all these engines usually went through 100 hour tests before service approval, tested for many many hours at full power, but with controlled oil and coolant temperatures.

As I understand the reason for Merlin engine failures in CLOD are probably related to:

a, Exceeding oil and/or coolant operating temperatures of the Merlin. Obviously engine failure is a very obvious conseqence of too high temperatures, so the real question is IMHO
aa, how long the Spit / Hurri could be run at + 6 1/4
ab) how long the Spit / Hurri could be run at + 12, which is about 30% more power/heat load.

b, Fall of oil pressure during negative-g manouvers, resulting that the engine is insufficiently lubricated, which can and will destroy an engine in very short order, any engine, and should be correct for the 1940 neg-g sensitve Spit/Hurri (which's manual specifically warns against negative-g and low oil pressure conditions), so I sense that Red pilots not knowing/ignoring this limitation may be at the culprit.
__________________
Il-2Bugtracker: Feature #200: Missing 100 octane subtypes of Bf 109E and Bf 110C http://www.il2bugtracker.com/issues/200
Il-2Bugtracker: Bug #415: Spitfire Mk I, Ia, and Mk II: Stability and Control http://www.il2bugtracker.com/issues/415

Kurfürst - Your resource site on Bf 109 performance! http://kurfurst.org
Reply With Quote