Nice Little Explanation of Carburetors

[MIflyer]

From WWII Flying Cadet Magazine.

 

[XBe02Drvr]

Nice!

 

[MIflyer]

I recall reading that the Germans used fuel injection in the DB engines, which prevented the Lean Cut/Rich Cut problems with a Merlin when the nose was shoved over. But the mechanical fuel injection systems used by the Germans required a great many more precision parts than did a carb.

In addition, the fuel injection approach did not cool the charge as the carb approach did, which added significant power.

The British adopted a standpipe in the Merlin carbs to feed fuel during negative G maneuvers and prevent the Lean cut and an orifice in the fuel supply line to prevent so much fuel entering the carb so to cause the Rich cut.

Eventually the British adopted the Bendix pressure injection carb, as the US did even before the war.

 

[Sid327]

......In addition, the fuel injection approach did not cool the charge as the carb approach did, which added significant power.....

I remember reading about this in the RR book ''The Merlin In Perspective.'' It mentioned RR had looked at fuel injection but felt they could make better power using a carburettor.

 

[XBe02Drvr]

It mentioned RR had looked at fuel injection but felt they could make better power using a carburettor.

IIRC, they eventually settled on the pressure carb, or as described above, the injection carb. It had the float carb's advantage of mixture cooling because it atomized fuel into the throat of the venturi, and fuel injection's immunity to Gs. It did, however, share two drawbacks of all carburetors: carb ice, and potentially uneven mixture distribution among the cylinders if intake manifold design was not optimum. A nice happy medium.
Cheers,
Wes