109 e3b against spitfire II

[Crumpp]

The fuel metering certainly does change when the fuel pump is pushing more fuel through the jets.

I did not catch your explaination of the your "stages" Milo, it is clearer what you are saying. I thought you were saying it was more serious in the second stage of the supercharger.

If you are in the second stage of your supercharger then your altitude is increased and the air density is decreased. To maintain the same ratio of fuel and air you must reduce the amount of fuel.

It is not a two "stage" event, it is two different types of cut outs you can experience with a float type carburetor. You can experience both of them in one flight pulling negative G's in your float type carbureted engine.

You either have a lean cut out or a rich cut out. A lean cut out occurs when you subject the airplane to rapid onset negative G such as a bunt. The float rises up and shuts off the flow of fuel.

A rich cut out occurs when you subject the airplane to low amounts of prolonged gradual onset Negative G. The float does not rise up and shut off the flow of fuel. Instead fuel continues to flow, the engine sputters and skips but does not cut out. The fuel collects in the top of the bowl forcing the float down, opening the fuel flow to maximum and flooding the engine. This is more serious because the engine will not automatically restart like a lean cut out will. The engine is flooded and the fuel amount must be reduced in the cylinders.

If you take a float carburetor and subject it to negative G's, the engine cuts out immediately in a lean cut out.

Even in a small 180hp Lycoming engine.....sipping 10 gallons per hour empties the bowl immediately.

Accident - The pilot of a southern California Long-EZ was seriously injured and his passenger suffered a broken hip when the airplane crashed into a dry riverbed. The eyewitnesses to the accident reported that the airplane was doing aerobatics. It appeared to enter the beginning of a loop, did not have enough speed, fell out of the maneuver. The engine stopped. (negative "g" will cause a carbureted engine to suffer fuel starvation) the aircraft nosed over and spiraled down to about 100 feet, where its wings were leveled and it descended until it struck the ground. The aircraft hit a 20 degree embankment almost wings level and slid forward only about two feet. There was no fire, although the right fuel tank was ruptured.

http://v2.ez.org/cp34-p5%28.htm

You take a large 12 cylinder Merlin gulping 120 gallons per hour and the small amount of fuel in the carburetor bowl will not last a blink of eye.....

The engine will quit....
The prop will windmill....

AND as soon as the float opens back up and fuel flow is restored the engine will restart.

Anything else is gamer fantasy.

Even with a TBI or pressure carburetor, if you pull asymmetrical loads, the engine will skip as the fuel metering changes....

The TBI must be mounted in an orientation that places the metering tube in a horizontal plane. If the metering tube is not in a horizontal plane, positive or negative "G" forces acting on the diaphragm will alter fuel metering.

http://www.ellison-fluid-systems.com...l/section2.htm