The turbochargers were given to the P38 due to politics and scarcity of turbochargers. tHe P38 was a fine plane but was used 2 turbochargers two motors and over twice the materials. The P40 could have used the turbocharger too.
P-39 vs P-40
- Thread starter gjs238
- Start date
One advantage on muddy or sleet filled airstrips was that the tail of the P39 was high and dry. The P40 and all other fighters would literally get frozen in the mud or have sand dirt and extra water on takeoff cause issues. I saw on Hustons film in the Aleutians in 1942 that P39s could easily albeit very slowly plow down the run way and takeoff. Russians also liked the tricycle gear for this reason. They also had an easier time with cold weather takeoffs with the liquid cooled not radial engines. The radials would actually need heating elements prodded in the front of of the motor and wait until it was warm enough to ignite. The antifreeze in the P39 would allow a subzero start up and go with the pilot prying open a frozen door. Prying open an iced canopy I gather would be more difficult than walking into the side door.
Don't fall to the 'not enough turbos' myth - XP-39 turbo installation was awful from drag standpoint, the XP-39 being unable to beat 350 mph mark as designed. Coupled with USAAC need to get a modern fighters in short time, turbo installation was deleted for on the XP-39B, and altitude-rated V-1710 was installed. On the P-38 turbo at least worked, and with less drag issues.
USA was not the only power to go with 2-engined fighter, the P-38 being an actually useful machine, with excellent performance when compared with US fighters of the time, and vs. many foreign fighters.
Granted, the P-40 with turbo would've been interesting. Unfortunately, the (X)P-40H never materialized.
swampyankee
Chief Master Sergeant
- 4,311
- Jun 25, 2013
I'm sure this was addressed before (I'm on my phone, so scanning several pages is difficult), but the P-39 prototype was turbocharged. Bell did such a poor job with the installation that performance was improved with the turbocharger's removal.
wuzak
Captain
The P-40 was designed specifically to not have a turbo. This was after Curtiss' experience with the XP-37 and YP-37s.
Later there was a push for a turbo version, not sure why it didn't get past the proposal stage. Perhaps production was more important at that stage.
Curtiss did build a version of the P-60 with Allison V-1710 and GE turbo, the XP-60A (XP-60 was powered by V-1650-1, XP-60B was to be V-1710 + experimental non-GE turbo, XP-60C and E by -2800s and the XP-60D was powered by a V-1650-3).
The original installation was deemed a fire hazard by the USAAF, and had to be redesigned. The XP-60 used a P-40 fuselage with laminar flow wings, so the installations could have carried over.
But I'm not sure it would have been all that successful, or timely.
Tomorrow,
I'm unfamiliar with the XP-40H. I found nothing on google. Pass a link if you have one please!
Cheers,
Biff
CORSNING
Tech Sergeant
The designations P-40H and P-40I were never assigned to any Curtiss
aircraft. Neither designation was assigned to any projects that I am
aware of either.
aircraft. Neither designation was assigned to any projects that I am
aware of either.
Tomorrow - that's hilarious
At pg. 162 of 'Vee's for victory', it is said that XP-4H was designation for the never produced variant of the P-40E. GE shipped a Type B-2 turbo to Curtiss 'immediately' after the Curtiss received authority for the project, that being June 19th 1941. However, by October 1941 that decision was revoked, the P-60 instead got the green light.
IIRC the designations ending with 'I' were never alloted due to fear that they might be confused with 'J' designations.
A lot of the Lend Lease P-39's came through Fairbanks, where I live. No stranger to Winter aircraft ops, neither inline or radial engines are starting at zero (F) without preheat. Yes the anti freeze (glycol mixture) might provide freeze protection well below zero, it needs to be heated to loosen up the oil enough to provide lubrication on startup. The cold mixture plus cold oil and resulting slow turnover are big obstacles! Sometimes with a radial you can get a couple of jugs going (only the top cylinders have prime) and eventually coax out a quorum. currently used air cooled piston engines use either electric cylinder heaters or a source of hot air, such as the famous "Herman Nelson" heater. No one that I know currently flies a liquid cooled aircraft engine in Arctic conditions, but our automobiles use electric block heaters of various types.
My (limited) understanding of the impetus behind the mid engine design was to reduce the pitch inertia by concentrating the mass toward the center.
My (limited) understanding of the impetus behind the mid engine design was to reduce the pitch inertia by concentrating the mass toward the center.
Issue with the P38 is that it got to the party so late. It missed 1942 in the Pacific and Nort Africa and the Russian front. The battles where the Allies won the war. P38, Vought Corsair, Hellcat, P51, P47 were still in development re-development, flight testing etc. Theier tardy designs got alot of Kamikazes and novice German pilots who never even got a shot off if they had machine guns at all. In 1942 the US and Australian and New Zealand pilots had almost no combat experience and less than oe equal to 40 hours of flight time.
CORSNING
Tech Sergeant
Tomorrow - that's hilarious
At pg. 162 of 'Vee's for victory', it is said that XP-4H was designation for the never produced variant of the P-40E.
It is said? Tomo, is there any indication WHO "it is said" by? Is there any elaboration
on the subject in 'Vee's for Victory'?
It is said by 'Aircraft and Jets', Vol.1 No.1 pg.17, June 1946, in article 'Evolution of P-40'. The delivery of turbo was footnoted: Teletype E-106 and PROD-T-665 of 6-10/12-1941 to Chief, Material Division, Wright Field; NARA, RG 342, RD 3466, Box 6841.
wuzak
Captain
It was all about the gun, the 37mm M4 cannon.
Some proposals were made by Bell where the engine drove an extension shaft to the prop so that a big cannon (25mm or 37mm) could fire through the prop. Some of these had the engine ahead of the pilot, the one that got the contract was, obviously, the mid-engined version that became the P-39.
http://bellaircraftmuseum.org/sites/default/files/bell_model_3_0.jpg
http://bellaircraftmuseum.org/?q=node/32
GregP
Major
According to Don Berlin's son, the P-40 was designed to include a turbo but was never allowed to get one in practice. He never said if this resulted in a shorter fuselage, but I'd surmise that if the contention is true, then there was some length deleted when the turbo didn't materialize. If that is NOT true, then the P-40 does not appear, to me at least, to have room for a turbo package in the existing short-fuselage version. Maybe in the long-fuselage version, as in a P-40M.
Don's son also said Don was allowed to build ONE P-40 with a turbo and that it gave great high-altitude performance. But I have never personally seen anything that would support that statement. That is, I've never seen anything that can be used to reference a turbo P-40 being actually completed. So, I have no personal knowledge of the subject to conform or deny it. I HAVE heard of P-40s being flown at 75" MAP and performing quite well with no detrimental effects being noticed upon return to field, and have spoken with a guy who flew the twin P-40 (see below):
![p-40c_twin[1].jpg](https://ww2aircraft.net/forum/attachments/p-40c_twin-1-jpg.519488/ "p-40c_twin[1].jpg")
But even HE never heard of the flying turbo P-40. I would surely like to have seen a turbo XP-40Q, for sure, or an XP-40Q with a 2-stage Merlin. Alas, neither were built.
Don's son also said Don was allowed to build ONE P-40 with a turbo and that it gave great high-altitude performance. But I have never personally seen anything that would support that statement. That is, I've never seen anything that can be used to reference a turbo P-40 being actually completed. So, I have no personal knowledge of the subject to conform or deny it. I HAVE heard of P-40s being flown at 75" MAP and performing quite well with no detrimental effects being noticed upon return to field, and have spoken with a guy who flew the twin P-40 (see below):
But even HE never heard of the flying turbo P-40. I would surely like to have seen a turbo XP-40Q, for sure, or an XP-40Q with a 2-stage Merlin. Alas, neither were built.
wuzak
Captain
Curtiss had a turbo V-1710 development of the P-36 - the P-37.
The turbos were unreliable, especially in the XP-37, less so in the YP-37.
From that experience Curtiss and Don Berlin sough a non-turbo "altitude rated" V-1710 to put with the P-36 airframe, this becoming the P-40.
The P-40 was even in competition with the P-37, and others, for a production contract, IIRC.
We do know that the P-40 fuselage could mount a turbo system, as the P-60 used an early model (P-40D or P-40E) fuselage.
But the P-40 was not designed to use a turbo, though a proposal for a later model turbo version was made.
The turbos were unreliable, especially in the XP-37, less so in the YP-37.
From that experience Curtiss and Don Berlin sough a non-turbo "altitude rated" V-1710 to put with the P-36 airframe, this becoming the P-40.
The P-40 was even in competition with the P-37, and others, for a production contract, IIRC.
We do know that the P-40 fuselage could mount a turbo system, as the P-60 used an early model (P-40D or P-40E) fuselage.
But the P-40 was not designed to use a turbo, though a proposal for a later model turbo version was made.
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Shortround6
Lieutenant General
Well, there is mounting a turbo in a P-40 fuselage and there is mounting a turbo in a P-40 fuselage.
This is the P-60A with the turbo Allison. Please note this aircraft has a 275sq ft wing.
It may have started as a P-40 fuselage but apparently a lot extra fairing was needed to hide all the turbo bits and pieces. Wingspan was 41 feet and it used a 11ft 8in prop. for it's 1425hp engine.
I would also note that the book " Curtiss Fighter Aircraft 1917-1948: a Photographic History" by Francis H. Dean & Dan Hagedrom
makes no mention of a P-40H and under the designation for P-40J simply says that while some sources claim that is the designation used for the turbo P-40E project ant that it was abandoned in May of 1942 no Cutiss records located at the time the book was published confirm the project. No AAF documents have been identified as confirming the project and an official AAF document "Model Designations Army AIrcraft" fated July 1942 says that the P-40J designation had not been assigned.
Please note that some sources say that Don Berlin had left Curtiss in April of 1942 to go to Fisher to work on the P-75. The above P-60 had been proposed and approved much earlier and indeed a contract for 1950 such aircraft had been given to Curtiss in late Oct 1941 only to be canceled right after Pearl Harbor. (Jan 1942) and the P-60 didn't commence testing until Oct of 1942 and the turbo was removed before the first flight in Nov.
P-39 Expert
Non-Expert
This is the problem with a turbo in a single engine plane. No matter what you start out with you end up with a P-47.
There is a small thing on the P-47, called the R-2800. As conceived, it was to offer an extra 3/4s of power vs. V-1710. Price being weight and size, not just of the engine, but of necessary plumbing, turbo and intercooler. Big fuel tank is needed, since big power needs a lot of fuel. Now that we're to install a 2000 HP engine on a fighter, a suitable armament s needed - 8 HMGs. As before you know it, the fighter gets big & heavy.
We can recall that P-43 was smaller than Hawker Hurricane or F4F, neither of the 3 being slim. On the other hand, Hellcat didn't needed a turbo to be as big as P-47.
Shortround6
Lieutenant General
It depends on how you measure size. The P-43 was certainly a heavy airplane for it's "small" size.
tested gross weight was 6918lbs with 145 US gallons of fuel on board which makes a P-43 about 400lbs lighter than a 12 gun Hurricane.
This P-43 weight is with two .50 cal guns and two .30 cal guns, no armor, no self sealing tanks.
Production P-43s were even heavier and the P-43A with four .50s was even heavier.
The light weight P-43 had trouble out climbing the Hurricane II and needed a bigger airfield.
tested gross weight was 6918lbs with 145 US gallons of fuel on board which makes a P-43 about 400lbs lighter than a 12 gun Hurricane.
This P-43 weight is with two .50 cal guns and two .30 cal guns, no armor, no self sealing tanks.
Production P-43s were even heavier and the P-43A with four .50s was even heavier.
The light weight P-43 had trouble out climbing the Hurricane II and needed a bigger airfield.
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