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Old 06-16-2011, 05:57 PM
Seadog Seadog is offline
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Quote:
Originally Posted by VO101_Tom View Post
What does this mean according to you then (copy from other topic)?

He wrote this:
1st August 1940 Memo from Downing re the Handling of the Merlin Engine
This note is advising the pilots that there is an increase in engine failures in the overuse of the emergency 12lb boost.
The interesting thing is that this memo was sent to ALL fighter groups. Had we been talking about the 16 squadrons or less this would not have been the case. It would have been sent to the squadrons involved.


I think, this unambiguous warning. If was used continuously the 12lbs boost, and the engine was ruined continuously, it does not interest, if COD makes the same one.
If you read Dowding's memo carefully:
http://www.spitfireperformance.com/dowding.pdf
he discusses a number of scenarios that result in engine oil starvation and/or overheating. The engines were failing, not just from overuse of 12lb/3000rpm but from overheating and lack of oil pressure. Steep climbs damage the engine from overheating, not overboosting. Inverted flying damages the engine from lack of lubrication not overboosting. Dowding memo is pretty clear: keep your gauges in the black! Yes, Dowding states not to use 12lb boost for more than 5 minutes, but the real culprit is overheating and lack of oil pressure. No sane pilot, in a combat situation, say with a 109 on his tail is going to worry about using 12lb/3000rpm for more than 5 minutes, and Dowding's memo is nothing more than a reminder to not use overboost except when really needed.
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