Modelling engine wear and WEP limitations

[Seadog]

Originally Posted by Crumpp

Who cares? The published Operating Instructions and Technical Orders for the Spitfire are clear.

They certainly are clear and Dowding's memo leaves no room for doubt.

Originally Posted by Crumpp

Dowding was not the technical expert on Rolls Royce engines. He had people to fill that role for him and he followed their advice.

He certainly did, which is why the memo is worded the way it is.

Originally Posted by Crumpp

It is a fact, ANY use of +12lbs in the Merlin engines requires a log book entry and a mechanics inspection before the engine is returned to service.

You seem to think that having the engine inspected after the extreme stress of over boosting is uncommon.

Almost every fighter aircraft engine in WWII had to have it done.

BMW, Diamler, Rolls Royce, Allison, and just about every else required it. It only makes practical sense.

Even OUR P51D Merlin had the same instructions:



I think you just want a magic win button for your game.

War emergency power on a Mustang!!!? The Mustang/Merlin 60 series was not the same as 12lb boost on a Merlin III:


67 inHg = +18 lbf/in² boost
61 inHg = +15 lbf/in² boost
46 inHg = +8 lbf/in² boost
44.5 inHg = +6 lbf/in² boost

so they are talking about pulling 18lb boost and 1700hp from a Merlin Engine with a two stage SC, or about 30% more power than a Merlin III at 12lb boost.

The Normal full throttle setting on the Mustang is 61" boost or 15lb boost and at that setting no extra inspection is required.

The Merlin XII was cleared for 12lb boost on T/O, so this was simply normal operations for a Spit II