lol!!

I don't think the devs have re-worked the G cutout in his patch, it 'feels' the same to me but if it has been reworked then that's that.

Not sure I follow what you mean regarding the 0.2G design threshold and the 0.017G cutout on unmodified engines but if the cutout on early engines was 0.1G it would make sense to have a design threshold (valve operation to prevent cutout) at a higher level so that it is already active before the 0.1G level is reached.

Sry the 0.017G theoretical value is the actual neg G you wld hve to push to experience a cutout on a non-modified Merlin. I mean that actual accel value wld be (1-0.017)G.

The doc is related to a redesign of the carb to allow at near zero G the engine to function properly. The 0G value is approximated as 0.2G in this computation as the way they ran the calculation, 0G was not permitted (see on top of pg 2 the ratio for the plumber calculation (counter-weight) - if G wld hve been 0 the ratio can't be calculated that way)

A new design had to be introduced latter for full neg G aerobatic which was not done on Uk produced Merlin as I can understand reading the extract of "A Merlin History" that was provided to us earlier.

Note also that the redesign involve an anti-vibration induced cutout device (a spring) that lead me to think that the Merlin encountered some vibration problem once fitted in fighter planes. My assumption goes for the Spitfire but only on the grounds of assumptions made on Sidney Cam's robust design.

This is probably a little bit irrelevant as it's a MkV, but it clearly shows what happens when the negative G cut outs occur.

If you watch and listen closley you can hear the engine misfire and see the smoke (especially when he's inverted). It happens quite a few times. Just thought it was interesting.

Alex Henshaw flight testing a MkV at Castle Bromwich 1941. (ignore the terrible acting bits!)

http://www.youtube.com/watch?v=nCmzYccyBYM

It is irrelevant at showing the effects of a float type carburetor. However it does clearly show that even "Miss Schillings" orifice and the SU pressure carburetor are still subject to effects from negative G. Only direct injection is immune.

Its not a MkV (no cannons) see wing detail at 0:21. Almost certainly a MkI.

One of the topics I discussed with Group Captain Peter Gilpin (who flew Spits for the entire war) was the introduction of the 'Ms Schillings orifice' and to what extent it solved the problem of neg G cutout. He told me that he could nose down and chase/attack without any problems.

See:

http://www.spitfireperformance.com/x4922.html

Mk Va's had rifle caliber machinegun armament just like the Mk I's.

Which has no bearing on the fact:

Does anyone else notice that it seems when you throw in the flaps on the Spit that you can put more Negative G load into it before the engine starts cutting out????

True. Sorry.