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I wonder if sending such proposals to individual aircraft manufactuers might have been another option for securing funding ... or at least swaing the Army for its need. Then again, I'm not sure how that sort of action would mesh with military bureaucracy at the time, or if it could have caused friction between Allison and the Army.
Were Pratt and Whitney's 2-stage supercharger developments funded in-house or NAVY supported? I seem to recall the auxiliary superchargers used on the R-1830 and R-2800 were somewhat similar in configruation to the sort eventually employed on the V-1710 (hydraulically clutched and running independently from the integral single-speed supercharger stage, including lacking any sort of intercooling -until late model R-2800s- though water injection was offered fairly early on for the 2-stage 2800s).
Bell and Curtiss lobbied against boosted engines for the P-39 and P-40. They didn't have room to accommodate them.
Wright engines at least got critical turbocharger development from NACA. Charged with a similar project for the Allison they pleaded an unworkable engine design.
Perhaps recognition of the need for a high-altitude, long-range escort came too late and was too critical to take a chance on the Allison with the Merlin in hand (pretty much).
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It was not quite the same thing for Allison as all Allison owned was the factory and production equipment, along with some patents on aircraft bearing design and valve design. The US Government in fact MADE Allison share their bearing patents with Rolls Royce for use on the Merlin. Allison bearings lasted MUCH longer than Roll Royce bearings did ... and there was a war on in which Eruope was at stake. Allison did not share their bearing design willingly, but they were in a bind. Refusal would amount to plant closure since they were told future Allison V-1710 production was in the balance.
You will note that Rolls Royce did not share their 2-stage supercharger design with Allison, despite there being a war on. Personally, I think that would have been a fair trade, bearings for superchargers, but Allsion was not in a position to demand terms and the 2-stage supercharger was developed after the bearing design information exchange. Allison was not forced to share valve design data and didn't.
The XP-39E was more of a prototype for the XP-63 than related to the rest of the P-39 family. It had 1ft 10in more wing span, 23 sq ft more wing area and a fuselage 1.75 ft longer. it also picked up around 1200-1300lbs of weight empty so something else was going on besides adding the 2nd stage on the supercharger.The XP-39E, a redesign of the P-39, flew 1st time in April 1942 with a two stage V-1710. The two stage V-1710 was installed in several XP-40Q aircraft, resulting in a good aircraft when Allies have had great aircraft already.
Tomo, Allison acq`uired the bearing design by US Government insistence. Of course they for paid. But tyhey would never have given the license if not for government insistence.
And that's why I said the trade of supercharger for bearings never happened ... precisely because the bearing license was mandaded well before the 2-stage supercharger was operational ... so it wasn't "on the table," so to speak, at the time. You don't seriously think a US company would license a technology that was making their bearings the only game in town ... unless they HAD to, do you?
If you do, you don't understand US business.
You will note that Rolls Royce did not share their 2-stage supercharger design with Allison, despite there being a war on. Personally, I think that would have been a fair trade, bearings for superchargers, but Allsion was not in a position to demand terms and the 2-stage supercharger was developed after the bearing design information exchange. Allison was not forced to share valve design data and didn't.
Sorry to go off topic for a minute but does anyone know why these engines weren't dohc? Was it cost or that the increase in power didn't significantly make up for the extra weight or, being bulkier, the loss in aerodynamics?
So the turbo was deleted from the P-39 and was never offered to Don Berlin for the P-40.
Then they withheld the turbos from all the fighters but the P-38. It had some issues at the start, but they were worked out within about 6 months here in the U.S.A. ... it took about another three months to work them out in Europe because we didn't know how much different European fuel was from US fuel. When we found out, they could then replicate the problem on the test stand and they figured it out.
The installation may HAVE been heavy, problematic, and appaling, but it was deleted because the War Marriel baords disapproved all turbochargers for US fighters except for the P-38 and P-47. They were saved for the heavy bombers because it was anticipated that Europe would require bombing from high altitude, and turbocharger production was low relative to aircraft and engine production. The P-63 used a 2-stage Allison with the Aux-stage blower.
Don Berlin NEVER WANTED a turbocharger for the P-40, but it was denied, and he designed the P-40 without one,
There are STILL rumors he was allowed to build ONE turbocharged P-40, and I have heard his son say it, but I have no proof of its existence, so it remains a rumor.
As for the double overhead cam, there is no need at all for one if you are already operating 4 valves per cylinder from a single overhead cam. The guys using DOHC couldn't figure out a way to use SOHC, or they WOULD have. SOHC is cheaper and more reliable. I can't say which has the better potential, but SOHC works VERY well in the V-1710.
With all the trouble the XP-37 had, I wonder how a turbocharged P-40 could have fared better. (maybe more mature turbocharger development paralleling the progress made on the P-38? ... or an earlier adoption of a liquid intercooler?)Don Berlin WANTED a turbocharger for the P-40, but it was denied, and he designed the P-40 without one,
There are STILL rumors he was allowed to build ONE turbocharged P-40, and I have heard his son say it, but I have no proof of its existence, so it remains a rumor.
Don Berlin, Chief Designerat Curtiss for the P-36 and P-37 aircraft, was frustrated by the continuing problems with the turbosupercharged Curtiss XP-37 [Models 75I ND 80i] and the lack of potential for the P-36. Given the urgency of the upcoming 1938 Pursuit Competition , he obtained from Allison an estimate for cost and performance of an "altitude" rated V-1710 for use in a P-36 derivative.
The P-63 seems more like a case of just being a more advanced airframe overall. It doesn't seem that unrealistic that the engines used in the P-63 series could have been fitted to variants of the P-39 itself. (though maybe some complications due to added length or change in CoG)The turbo was supposed to give the P-39 good altitude eprformance, but was deleted by hook or by crook or the War materiel Board or whomever. The very similar but larger and later P-63 dispensed with the turbo and got good high altitude pserormance from the 2-stage Allison.
I thought that was relevant ... maybe not.
Good enough to be a reasonable substitute for the Mustang had NA not developed that machine on their own, especially if the merlin engined P-63 project had gone though. (Mustang production started sooner and the USAAF didn't put in massive orders for the P-63, so it's hard to say how well they'd have coped with ramping up production compared to what NA managed historically)But the basic design as developed in the best P-63s would have given any other WWII psiton fighter a good run for the money. Perhaps not a jet ... but, then again, none of pistons could either, despite shooting them down in decent quantities. Most of the jet kills were ambush, landing pattern, or some jet malfunction rather than "catching" the jet when he was aware and up to speed an in combat mode.