hi,
im looking for a mod which made the Spitfire (and also Seafire) more realistic.
eg. the g-behaviour of the engines-carburetter isnt simulated in IL-2 (dont know why)
Is there a mod available?
I believe it was only the Spit I that had the neg G engine stall from the carb. The other spits were fuel injected
No, there was only one spit version (sorry, i dont know which it was, but i have book where i can find it, so if you want i look for it :-) ) where it was tried to solve the problem (but i did not work at all).
The AAA Spitfire Mk.I got the cut out behaviour of the early Spitfire up to Mk.II. The Spitfire Mk.V and later got the Merlin 45 (and later Merlin marks) which had that problem solved by a diaphragm. So the behaviour on neg. Gs are correct.
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.
That cutout problem was not related to just few Spits and Hurricanes. That cut out problem was not solved before early 1941. First on March 41 the Fighter Command was fitted out with a field mod that solved that cut out problem during short negative phases. A really satifiying solution first went into action with intrucing the Mk.V into action.
Are you sure it was that late Kimura? I argued this once before and was linked to documentation suggesting otherwise. Some British chick actually came up with the surge plate and it was initially named after her. Hers was a simple improvisation, later standardised in more refined form for manufacture in the later series Merlins, but I'm pretty sure they were first issued in or around Oct40.
Initially it just consisted of a metal disc with holes drilled into it, and that was fitted to the earlier series Merlins currently in RAF equip, well before the MkV.
I've also heard RAF pilots talk about its introduction "by the end of the Battle of Britain" although admitedly some pilots consider the BoB to have continued into 1941.
Anyone got a link?
All I can find so far is "the Shilling modification (re.Mrs Shilling) became standard equipment by March 1941 but the problem was not properly fixed until a new kind of SU carburettor was fitted in 1942, with a further improvement among two stage Merlins during 1943 with an improved Bendix-Stromberg carburettor..."
But again I'm certain I've read references where its initial introduction was during the later stages of the BoB. The point is probably mute.
Alpha, the MkI Spit and Hurricane modelled I believe both already have the fuel surge issue. The MkI Hurricane additionally uses a variable pitch propeller with no constant speed mechanism (it represents export Hurricanes fitted with finnish props I think) and has a maximum boost of +6lbs (it was +6 and not +8 on standard grade 87/100).
Vanir - You're referring to "Miss Shillings orifice" (officially Miss Shilling's diaphragm, but I like the pilot's version better) which was a modification on the float carburettor.
AFAIK they were first fitted in '41 and they didnt solve the problem. They let a pilot bunt over, but not maintain inverted flight. Books say it was first used early '41 and was in common use by March, but I dont have the time at the moment to dig up exactly when it was first used. Looks to be after the BoB though.
The starving of fuel could shut down the engine completely if the negative g continued by the way, such as in an outside loop or inverted flight, not just a power loss.
In Robert Johsons book "Thunderbolt" he said he flew the Spit V. He was surprised that it's engine died when he went inverted. He noted that that the Spit IX did not have that problem. That was at least late 1942 or early 1943 so the problem apparently still existed at that time.
Also the new Spit XII by MrJolly sputters under negative g.
