Super P-39?

[Shortround6]

Space in front of the landing gear is pretty much used up by the reduction gear.

The is length and there is length.

Granted these a re P-40 pictures.

The standard Allisons tend to "taper" at lot more at the rear. With both engines the length included some "accessories" but the two stage Merlin had a lot more bulk in the lower rear. Engine bays were not 30 in wide, 36 in high 80 in long empty boxes with square corners.

 

[jmcalli2]

The two stage Merlins were vastly a better engine than the single stage ones, even if the intercooler installation is less-than-ideal, as it was in Spitfire. The Spit IX was both faster and better climber than the Spit V, if we compare the same altitude oriented versions.

1st question about Merlin: can the engine be mated with extension shaft? The V-1710 was a rather modular engine, with reduction gearbox fully detachable, so the extension shaft was rotating at camshaft speed. What was case for Merlin?
2nd question: what would offer the (presumed) Packard Merlin, vs. the historical V-1710? The best performing types, like the -Q subtypes, were making some 385 mph @ ~16500 ft, military power (1125 HP), with external guns. Without external guns, the speed was up some 10 mph, and at WER (1420 HP), no. ext guns, the charts show more than 400 mph at ~10500 ft. No wonder Soviets loved them.
At 23-24000 ft, such planes were still able to do 380 mph. Mind you, those were almost as fast as the P-51A, and somewhere between Spit V and early Spit IX. It was also faster than P-40F (Packard Merlin, 1 stage).
The V-1650-1 makes the rated power (1120 HP) some 3000 ft higher altitude than the V-1710-85 from the P-39Q (18500 ft vs. 15500), the P-39Q engines having the 3500 ft advantage on their on vs. 'plain' P-39D. So the high altitude performance would've received another boost, while the low alt performance would not suffer, due to two-speed supercharger.

In order for the 2 stage Merlin to be installed, the intercooler also needs to be installed, the best spot being maybe under the belly, the drop tanks going under wings. Wings needing some reinforcements.
The engine air intake needs to be at another spot (side of the airplane?), not being shadowed by canopy might allow for better harvesting of ram effect, esp. if the intake is elongated?

The main shortcoming: would the problematic stall behavior get even worse, with heavier engines installed behind CoG?

 

[Kevin J]

Hey guys, I know what I have heard. You don't have to agree. Nobody in 1940 did an airplane in 120 days; it took years.

General Davy Allison (no relation to the engine company), who demonstrated the P-40B/C to Chenault, stated that North American had the XP-40Q plans before they designed the XP-51 (or NA-73). He visited our airshow and the shop and, yes, we let him start our run engine on the stand. He loved it and told some stories. I don't disbelieve him. The preliminary drawings were available well before 1942, especially to the designers and the USAAC, who believed they owned them since they were the customer.

Heck, the DOD just recently sent Boeing and Lockhhed-Martin each other's porposals for the new tanker to the wrong companies! Anybody remember that? And that was pure horsecrap; they fostered competition. Anybody who believes that was a mistake is in never-never land. ... and Japan is now flying the Boeing tanker while we still aren't.

Sure, it was all a nice, 120-day development ... interesting it was never repeated, isn't it, even in the face of wartime necessity? How long did the P-47 take? Or the F4U Corsair? Or the P-39 or P-63? Or even the Curtiss-Wright CW-21? Or the P-61?

Your opinion may vary, and that's OK with me. Maybe there wasn't any Kennedy conspiracy either. Only one guy who could put two bullets into close targets at 120+ yards in only a couple of seconds with an old beater Russian gun that can't DO that in anybody else's hands including a head shot? I'm not that much of a believer ...

Miles M20 was designed and flown in 63 days in 1940.

 

[Kevin J]

I love the P-39 just the way it was. Produced the top scoring aces on the Allied side.