P-63: real performance?

Old topic, but new infos from the great YouTube channel, Greg's Airplanes and Automobiles:


View: https://www.youtube.com/watch?v=D7eWmBVlF9I

View: https://www.youtube.com/watch?v=5YbL6U0yxF4

Before S Shortround6 comments...
It is unfortunate - but not unusual - for Greg to choose and pick stuff. The ~430 mph speed figure for the P-63C seems to be from the Bell preliminary estimates. The seasoned scholars (not me) dealing with Bell pre-1950 aircraft will recall that Bell's figures need to be taken with a truckload of salt. We can see one such chart here, where the P-63A was advertised as a ~425 mph fighter, only to be tested at around 400 mph (here). So if the -A was slower by some 25 mph than it was advertised, there is a lot of the reasoning that the -C is also much slower than 430 mph at it's best altitude.
Then we have a comparison of the engine from the P-63C vs. the Merlin that was phased out from the production, the V-1650-3. The 1st P-63C was delivered on December of 1944 ( half a year after that performance chart is dated), by what time Allies were flush with the -7 powered P-51s. These engines were a tad worse at very low altitudes and at about 15k ft than the V-1710-117 engines, but far better at other altitude bands, and especially above 17-18 kft. Above 20 kft, there is really no competition. Pour in the 150 grade fuel, and the Merlin is better at any altitude.

For an american company that delivered on promises, see NAA.

America's Hundred Thousand by Francis Dean has 21 "Best" categories in the fighter comparison section, the top 5 to 8 usually mentioned per category, the P-63A is mentioned in 7, best finish 3rd for engine controls. First P-63C accepted in November 1944, first of the XF8F-1 in February 1945 if it comes to best US WWII dogfighter. The P-63A top speed is generally given as 410 mph

First of what the reports call V-1710 2 stage built in December 1942, a month after the first Merlin 2 stage by Packard, like Packard single figure monthly production until April 1943. Merlin production takes off from there, Allison tries to but is back to 1 in September, production builds to 300 in January 1944, peak of 363 in May, back to 11 in September and 12 in October 1944, hits a peak of 362 in January 1945, down to 3 in July.

2 Stage engines, 1942: 1 Allison, 5 Merlin, 1943: 514 Allison, 2,792 Merlin, 1944: 2,867 Allison, 15,736 Merlin, Jan to Aug 1945: 1,628 Allison, 12,885 Merlin.

Geoffrey Sinclair said:

First of what the reports call V-1710 2 stage built in December 1942, a month after the first Merlin 2 stage by Packard, like Packard single figure monthly production until April 1943. Merlin production takes off from there, Allison tries to but is back to 1 in September, production builds to 300 in January 1944, peak of 363 in May, back to 11 in September and 12 in October 1944, hits a peak of 362 in January 1945, down to 3 in July.

2 Stage engines, 1942: 1 Allison, 5 Merlin, 1943: 514 Allison, 2,792 Merlin, 1944: 2,867 Allison, 15,736 Merlin, Jan to Aug 1945: 1,628 Allison, 12,885 Merlin.

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Thank you for the figures.

It was too bad that powers that were didn't insisted on the P-51 powered by the 2-stage V-1710 until it was too late to matter.

Not really.
The 2 stage Allison was not ready for prime time until around 1 year after the 2 stage Merlin ( US production).
The lack of intercooler was a really handicap for high altitude operation. Water injection was useful but not complete substitute.
Without a a major change in R&D to change the time line you are going to get a 6-9 month delay in P-51s escorting thr 8th air force

Shortround6 said:

Not really.
The 2 stage Allison was not ready for prime time until around 1 year after the 2 stage Merlin ( US production).

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I'm fine for the 2-stage V-1710 P-51s to be coming from the production line at Bell from the late 1943.

Shortround6 said:

The lack of intercooler was a really handicap for high altitude operation. Water injection was useful but not complete substitute.

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We'd still be much better than any Fw 190A, and at least as good as the Fw 190D-9, and a full year earlier than the D-9.
1944 will see a bit of improvement with the -101 and -121.

Shortround6 said:

Without a a major change in R&D to change the time line you are going to get a 6-9 month delay in P-51s escorting thr 8th air force

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The Merlin Mustang is still on as per historically.

Whatever it did back in the day, today it makes for a very cool warbird...