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lookatsix
08-17-2004, 08:53 AM
why is the early spit untill (Mark 8) engine not cutting of under negative G
or positief G

i should be cutting feul of, under very strong manouvers especial when diving down

the spits had carburator, not like the Bf 109 and FW190 with injection feul pump

they fixed it until when the spit mark 8 was out not before that

lookatsix
08-17-2004, 08:53 AM
why is the early spit untill (Mark 8) engine not cutting of under negative G
or positief G

i should be cutting feul of, under very strong manouvers especial when diving down

the spits had carburator, not like the Bf 109 and FW190 with injection feul pump

they fixed it until when the spit mark 8 was out not before that

VW-IceFire
08-17-2004, 09:02 AM
Check your sources....the Mark I was the only Spitfire that really had negative G cut out problem. The problem had an improvised fix for the early versions and was largely sorted out by the Mark V as far as I know.

Read this as you will:
"ne of the great problems as discerned by pilots was the tendency for the carburetted engine to cut out under negative 'g'. Luftwaffe pilots learned to escape by simply pushing the nose of their aircraft down into a dive, as their fuel- injected engines did not cut out under these circumstances. Many authors have criticised this aspect of the Merlin design. In reality, like most engineering, it resulted from a design compromise- the drop in temperature developed in a carburetor results in an increase in the density of the fuel-air mixture when compared to that of a fuel injection system. As a consequence the Merlin produced a higher specific power output (horse power per pound) that the equivalent German engine. It was felt that this gave a higher power to weight ratio for the fighter and (rightly or wrongly) that this outweighed the disadvantages. By 1941 Miss Tilly Shilling in Farnborough had developed a partial cure for the problem. A diaphragm across the float chambers with a calibrated hole (the infamous "Miss Shilling's orifice"!) allowed negative 'g' manouvres, and was fitted as standard from March 1941. Sustained zero 'g' manouvres were not sorted out until somewhat later. In 1942 an anti-g version of the SU carburetor was fitted to single and two-stage Merlins. 1943 saw the introduction of the Bendix-Stromburg carburetor which injected fuel at 5psi through a nozzle direct into the supercharger and was fitted to the Merlins 66, 70, 76, 77, and 85. The final development was the SU injection carburetor which injected fuel into the supercharger using a fuel pump driven as a fuction of crankshaft speed and engine pressures, which was fitted to the 100 series Merlins."
(http://www.spitfiresociety.demon.co.uk/engines.htm)

From what I've been told by a Spitfire pilot, you shouldn't dive any Spitfire for extended periods of time because of the oil feed not getting into the engine. This is like not flying upside down for more than 7 or 8 seconds (mentioned in the P-38 training video). None of those things are modeled.

If negative G cutout is to be modeled...it would be under an excessive negative G load.

http://home.cogeco.ca/~cczerneda/sigs/tmv-sig1.jpg
RAF No 92 Squadron
"Either fight or die"

92SqnGCJimbo
08-17-2004, 02:46 PM
yes the mkv was devoid of this problem except when u tried to do an inverted loop. (this is what was deemed nessacary to cut the engine.

p.s nice one ice like the photo works

http://groups.msn.com/_Secure/0RwAAAKYUV9WohzlTekrEej5FgrwxWyQ0S3cejYO2W5yCX7kWI qN7NAF5NXMr5DiDrxaAeMyIENpTJL8fBCRH3F0Q*37BNoLmDuO BgZw7pgA/dhm2110.jpg?dc=4675481137574892891