22.04.2009, 01:56
Only early Spits and Hurricanes had this issue. By late 40 a surge plate was introduced into the carburettor fuel bowl which solved the problem. You would still lose a little horsepower in negative g manoeuvres (it effectively leans out the mixture) but the engine didn't cut.
Another early issue Spits and Hurricanes had was the Watts prop (two blade, no variable pitch), then the early De Havilland prop (three blade, two preset pitch settings) then finally the Rotol and later De Havilland (full variable pitch and constant speed mechanism).
Also early Merlin engines had +8lbs boost but this was soon increased to +12lbs when high octane 130 grade aviation fuel became widely used (previously 100 standard grade aviation fuel which is approximately equivalent to general aviation fuel used throughout Europe, Russia for example).
So in the Battle of France a MkI Hurricane would probably have +8lbs and a 2-pitch metal three blade prop. Spits at Dunkirk might have the same or the newer spec +12lbs and constant speed prop. During the BoB most of either had the latter and by the end they all had carby surge plates and the MkII Spit was in equip. 1941 and it was MkV Spit and MkII Hurricane and 130 grade had long since been standardised for the RAF. Power on the Merlin 20-50 series was well up and there was a huge outlay of supercharger options.
Similarly Germany had gone from A3 standard grade to B4 synthetic with improved knock rating and C2 natural high octane roughly equivalent to British 130 grade, then C3 synthetic which has the burn qualities of 130 grade and the knock rating of American "super high octane" 150 grade (ref: Crumpp of "White 1" Fw190A restoration project). But they never had surge problems due to direct injection since the old Jumo 210D in the Me109C (109D reverted to caburettor but had a 3 month service life before being replaced by the 109E) and despite popular British propaganda Germany was well ahead in development and service issue of adjustable pitch mechanisms (culminating in the aeromechanical screw which wasn't widely adopted elsewhere until the 1980's and was still regarded new technology then).
Long story short, it'd be nice to see your suggestion in a mod, though it should be recognised it existed for only a few hundred aircraft out of several thousand produced, during the earlest combat deployment period and these disadvantages were not long tolerated by the Air Ministry or RAF.
edit. oh and as mentioned above the Spit MkI MOD has the fuel surge issue modelled. Can't remember if the MkI Hurricane has it too (it should). A MkII Spit wouldn't have the problem, also later MkI Spits and MkI Hurricanes don't have this issue either (from October 1940 iirc).
But I'd like to see a watts prop MkI Hurricane, plus a +12lbs late MkI Hurricane with the surge plate, plus an early MkI Spit with +8lbs and a variable pitch prop without constant speed mechanism, and a MkII Spit with the higher performing engine.
These would really round out Battle of France and Battle of Britain mission building.
Another early issue Spits and Hurricanes had was the Watts prop (two blade, no variable pitch), then the early De Havilland prop (three blade, two preset pitch settings) then finally the Rotol and later De Havilland (full variable pitch and constant speed mechanism).
Also early Merlin engines had +8lbs boost but this was soon increased to +12lbs when high octane 130 grade aviation fuel became widely used (previously 100 standard grade aviation fuel which is approximately equivalent to general aviation fuel used throughout Europe, Russia for example).
So in the Battle of France a MkI Hurricane would probably have +8lbs and a 2-pitch metal three blade prop. Spits at Dunkirk might have the same or the newer spec +12lbs and constant speed prop. During the BoB most of either had the latter and by the end they all had carby surge plates and the MkII Spit was in equip. 1941 and it was MkV Spit and MkII Hurricane and 130 grade had long since been standardised for the RAF. Power on the Merlin 20-50 series was well up and there was a huge outlay of supercharger options.
Similarly Germany had gone from A3 standard grade to B4 synthetic with improved knock rating and C2 natural high octane roughly equivalent to British 130 grade, then C3 synthetic which has the burn qualities of 130 grade and the knock rating of American "super high octane" 150 grade (ref: Crumpp of "White 1" Fw190A restoration project). But they never had surge problems due to direct injection since the old Jumo 210D in the Me109C (109D reverted to caburettor but had a 3 month service life before being replaced by the 109E) and despite popular British propaganda Germany was well ahead in development and service issue of adjustable pitch mechanisms (culminating in the aeromechanical screw which wasn't widely adopted elsewhere until the 1980's and was still regarded new technology then).
Long story short, it'd be nice to see your suggestion in a mod, though it should be recognised it existed for only a few hundred aircraft out of several thousand produced, during the earlest combat deployment period and these disadvantages were not long tolerated by the Air Ministry or RAF.
edit. oh and as mentioned above the Spit MkI MOD has the fuel surge issue modelled. Can't remember if the MkI Hurricane has it too (it should). A MkII Spit wouldn't have the problem, also later MkI Spits and MkI Hurricanes don't have this issue either (from October 1940 iirc).
But I'd like to see a watts prop MkI Hurricane, plus a +12lbs late MkI Hurricane with the surge plate, plus an early MkI Spit with +8lbs and a variable pitch prop without constant speed mechanism, and a MkII Spit with the higher performing engine.
These would really round out Battle of France and Battle of Britain mission building.