More proof that the P-39 rules! 😂

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I read somewhere that the engines used on these aircraft did not have tight tolerances between the pistons and cylinder walls and most of that "black soot" was actually engine oil getting blown out from the exhaust valves. I've been trying to find the article that mentions this.
 
I figured it was running a rich fuel mixture, since it was a racer.

My '68 Chevell had a 502 big block running 12.5:1 compression with a Hillborn MFI that metered a rich air-fuel mixture, allowing it to run optimum at peak RPMs, but when it was at idle or lower RPMs, it was a smokey bastard.
 
A weight table for the Cobra II shows 1488lbs of fuel and 747lbs of water/alcohol mix.
There was some very heavy liquid consumption during the race. They not only stuck a 25 gallon P-63 water tank in the wing, they stuck a 75 gallon tank in the nose.
They also stuck a fuel tank in the rear of the fuselage in addition to putting thin wall bladders in place of the normal fuel cells.
 
Makes me wonder really hard how it handled since the 4-blade prop represents an increase in vertical surface area forward of CG without a corresponding increase in vertical surface area aft of CG. There was more than one P-39 that didn't handle at all well with a 4-bladed prop.
 
some of the racers had metal covered rudders and elevators.
I have no idea if that helped or hurt the control response but it should have cut a bit of the drag.
The Book "Cobra" by Birch Matthews has got full page weight comparisons for the 1946 Cobra II, the 1946 Tucker Special and the 1946 Lilly racer.
What they are not telling you is the change in the CG.
The Cobra II had 478.8lbs taken out of the empty weight, but they added 527.5lbs to the useful load (Fuel, oil and water/alcohol) and that was after they got rid of the guns, ammo gun, sight, oxygen equipment, 109lbs worth of radio (they left 20lbs), flare pistol, armor plate and armor glass.

I wouldn't even want to begin to guess how theses flew compared to the service aircraft.
 
Oh, and you could order top stitched hand tooled leather seats and steering wheel cover as a premium.
 
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