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Thread: Could the P36 have become America's Zero?

  1. #31
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    The early P-40 may have not been that much worse in maneuverability than the P-36. And early P-40 (no letter) was about 15% heavier than a P-36 (?) or Hawk 75 with P&W engine ( some of the figures for the P-36 are a little unbelievable compared to the HAWK 75 factory brochure). A P-40E clean is about 40% heavier which helps explain where the maneuverability went ( those six .50 cal guns in part).

    People would do well to remember that the P-36 had some initial troubles ( wing skin wrinkling for one) and may have gained a bit of weight on it's own had it stayed in production instead/in addition to, the P-40.

    From Joe Baugher's web site; " . However, the new Curtiss fighters began to encounter an extensive series of teething troubles almost as soon as they reached the field. Severe skin buckling in the vicinity of the landing gear wells had appeared, dictating increased skin thicknesses and reinforcing webs. Engine exhaust difficulties and some weaknesses in the fuselage structure were also encountered. Despite both production line and field fixes, the P-36As were grounded again and again. At one time, the 20th Pursuit Group was down to six serviceable P-36As, and even these planes had to be flown under severe limitations on their speed, aerobatics, and combat maneuvers. "


  2. #32
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    Quote Originally Posted by swampyankee View Post
    The P-36 could certainly have had significant performance improvements, simply due to increased engine power. I suspect, too, that it could do with a bit of aerodynamic clean-up, especially with regards to its engine installation. It is, of course, more difficult to design a good air-cooled engine installation than that of a water-cooled in-line, but it's certainly possible to design a clean engine with a radial. Compare the zero-lift drag coefficient of the F4U and that of the Bf109. The latter was reportedly about 0.029, or about 30% greater than the Corsair's.
    The 1200hp of the R-1830-17 as installed on the P-36C were pretty much end of the line for the engine. Instead of raw power (as in higher octane fuel, more boost), it would have needed a better supercharger to have this power available at higher altitude. This doesn't come for free, as pointed out elsewhere in the topic by shortround6 - it adds weight and costs space.
    The F4U has a lower drag coefficient also because it has a larger reference area. The wing is nearly twice as big, so a 30% higher drag coefficient means 30% less total drag for the 109. You can't just take some coefficient, it means nothing.
    Quote Originally Posted by pinsog View Post
    I guess no one told the Japanese the Zero was a poor performer. There was a squadron of Spitfire veterans from the BOB that were sent to Austraila and got their butt's handed to them by Zero's. The Spitfires that tangled with Zero's in 1942 didn't fair to well.
    That's not an aircraft problem, but a tactics problem. The AVG fought with their P-40's against A6M since early on, used proper tactics and was highly successful under bad operating conditions.

  3. #33
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    Quote Originally Posted by swampyankee View Post
    The P-36 could certainly have had significant performance improvements, simply due to increased engine power. I suspect, too, that it could do with a bit of aerodynamic clean-up, especially with regards to its engine installation. It is, of course, more difficult to design a good air-cooled engine installation than that of a water-cooled in-line, but it's certainly possible to design a clean engine with a radial. Compare the zero-lift drag coefficient of the F4U and that of the Bf109. The latter was reportedly about 0.029, or about 30% greater than the Corsair's.
    The 'late P-36' could also use a better layout of exhaust stacks, that would provide some additional thrust when compared with the historic one. As done on XP-42?
    The two speed engine should add another boost in performance, the deletion of fuselage MGs and ammo providing more space neccesarry for next step, two stage engine - again as with XP-42?
    The armament - 4 HMGs should do.

    The Cd0 of the Bf-109 was between .0225-0.024, depending wheter it was F/early G, or E/late G?

  4. #34
    Senior Member The Basket's Avatar
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    Quote Originally Posted by pinsog View Post
    I guess no one told the Japanese the Zero was a poor performer. There was a squadron of Spitfire veterans from the BOB that were sent to Austraila and got their butt's handed to them by Zero's. The Spitfires that tangled with Zero's in 1942 didn't fair to well.
    You are right no one did tell the Japanese as they kept building them. A Zero against a Buffalo is ok but not against a Corsair. Considering that even the best Zero model was slower than a Spitfire I shows that.

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    Quote Originally Posted by JtD View Post
    The 1200hp of the R-1830-17 as installed on the P-36C were pretty much end of the line for the engine. Instead of raw power (as in higher octane fuel, more boost), it would have needed a better supercharger to have this power available at higher altitude. This doesn't come for free, as pointed out elsewhere in the topic by shortround6 - it adds weight and costs space.
    The F4U has a lower drag coefficient also because it has a larger reference area. The wing is nearly twice as big, so a 30% higher drag coefficient means 30% less total drag for the 109. You can't just take some coefficient, it means nothing.
    That's not an aircraft problem, but a tactics problem. The AVG fought with their P-40's against A6M since early on, used proper tactics and was highly successful under bad operating conditions.
    The AVG didn't fight against A6Ms. Their fighter opponents were Army Ki -27s and Ki-43s.

    Duane

  6. #36
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    To my knowledge, most of the opposition was IJA, but the IJN used China as a test bed for the A6M, and on occasion ran into the AVG. But at any rate, tactics against the Ki-43 are the same that work against the A6M.

  7. #37
    Senior Member swampyankee's Avatar
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    Quote Originally Posted by JtD View Post
    The 1200hp of the R-1830-17 as installed on the P-36C were pretty much end of the line for the engine. Instead of raw power (as in higher octane fuel, more boost), it would have needed a better supercharger to have this power available at higher altitude. This doesn't come for free, as pointed out elsewhere in the topic by shortround6 - it adds weight and costs space.
    The F4U has a lower drag coefficient also because it has a larger reference area. The wing is nearly twice as big, so a 30% higher drag coefficient means 30% less total drag for the 109. You can't just take some coefficient, it means nothing.
    That's not an aircraft problem, but a tactics problem. The AVG fought with their P-40's against A6M since early on, used proper tactics and was highly successful under bad operating conditions.
    Please don't try to tell me how aerodynamic coefficients work. The F4U-1 had a slightly higher wing loading than the Bf109 and was a much larger aircraft. A lower wing loading will tend to decrease the value of zero-lift drag coefficient, so, if anything, the F4U was relatively cleaner than the comparison of Cd,0 would show. Just about all single-engined fighters of WW2 had Cd,0 between about 0.021 to about 0.025, whether using V-12s or radials, with no demonstrable superiority of one over the other, except for the Mustang, which was easily had the lowest Cd,0 of any production WW2 combat aircraft.

  8. #38
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    Try looking at the actual drag and not coefficients. The drag of the P-36 was 22% higher than the prototype XP-40 in it's last configuration. That is computed by HP vs speed at a certain altitude but may not include exhaust thrust (about zero on a P-36) Later P-40s got worse, heavier and more bits and pieces sticking out or more holes creating turbulence. P &W got the difference down to 8% with their test mule (NOT the XP-42) but they appear to be using exhaust thrust. The Test mule was an early P-40 (no letter) airframe and more than likely had no self sealing tanks, no armor and no guns making it very close in weight to the XP-40.
    Since ALL THREE aircraft used just about the same airframe except for engines and minor things like landing gear doors it is about the best comparison that I can think of, instead of trying to compare vastly different aircraft using coefficients.

  9. #39
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    Quote Originally Posted by swampyankee View Post
    Please don't try to tell me how aerodynamic coefficients work.
    OK. If you don't want me to do it, you best ask someone else.

  10. #40
    Senior Member swampyankee's Avatar
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    I'm not going to argue that the P-36 was aerodynamically inferior to the P-40, just that the P-36 did not have as well-designed an engine installation as did many other radial-engined fighters, probably because it was one of the earlier ones, and did not get the kind of attention that was given to the F4F. The USAAF could have paid to put the P-36 into NACA's full-scale wind tunnel as was done with the F4F-3.

  11. #41
    Senior Member swampyankee's Avatar
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    Quote Originally Posted by JtD View Post
    OK. If you don't want me to do it, you best ask someone else.
    I've done that decades ago. I'm a recovering aerodynamicist.

  12. #42
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    Quote Originally Posted by swampyankee View Post
    I'm not going to argue that the P-36 was aerodynamically inferior to the P-40, just that the P-36 did not have as well-designed an engine installation as did many other radial-engined fighters, probably because it was one of the earlier ones, and did not get the kind of attention that was given to the F4F.
    And there you have it. NOBODY had well designed radial installations in 1936-41 compared to what was being done in 1942-45. They were working on it, and working on it hard but it took time and a lot of failed experiments to get on the right path.
    The timing for a good radial engine installation is "just" too late to have any real effect for a service aircraft in 1942 (FW 190 was the exception) To be in service in 1942 in numbers, it had to go into production in 1941 which means the design had to be finalized when in 1941?

    It wasn't just a bit of clean-up in a wind tunnel that helped the F4F, it is the fact that the 2 stage engine used offered 1000hp at 19,000-20,000ft compared to the 600-630hp that the engine in the P-36 supplied.

    A newer version of the two stage engine in the F4F did propel the P&W test Mule aircraft to over 380mph in the fall of 1942 but that is much too late to have any effect on the course of the war.

    We are getting into what ifs like "what if" Curtiss could have used the P-51 wing and radiator in 1938 on the P-40?

    The XP-42 is a P-36 airframe and went through something like 13-14 different cowls and engines with extended shafts and short shafts while they worked on reducing drag for air cooled engine WHILE still getting acceptable cooling. This all took time. Vultee tried the extended shaft engine and pointy nose on the first Vultee 48 (P-66) and had to give up on it.

    Everybody KNEW there was a drag problem. A number of people were spending time and money on solving it. They did solve it, just not in time for 1942.

  13. #43
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    Quote Originally Posted by Shortround6 View Post
    And there you have it. NOBODY had well designed radial installations in 1936-41 compared to what was being done in 1942-45. They were working on it, and working on it hard but it took time and a lot of failed experiments to get on the right path.
    The timing for a good radial engine installation is "just" too late to have any real effect for a service aircraft in 1942 (FW 190 was the exception) To be in service in 1942 in numbers, it had to go into production in 1941 which means the design had to be finalized when in 1941?

    It wasn't just a bit of clean-up in a wind tunnel that helped the F4F, it is the fact that the 2 stage engine used offered 1000hp at 19,000-20,000ft compared to the 600-630hp that the engine in the P-36 supplied.

    A newer version of the two stage engine in the F4F did propel the P&W test Mule aircraft to over 380mph in the fall of 1942 but that is much too late to have any effect on the course of the war.

    We are getting into what ifs like "what if" Curtiss could have used the P-51 wing and radiator in 1938 on the P-40?

    The XP-42 is a P-36 airframe and went through something like 13-14 different cowls and engines with extended shafts and short shafts while they worked on reducing drag for air cooled engine WHILE still getting acceptable cooling. This all took time. Vultee tried the extended shaft engine and pointy nose on the first Vultee 48 (P-66) and had to give up on it.

    Everybody KNEW there was a drag problem. A number of people were spending time and money on solving it. They did solve it, just not in time for 1942.
    What is the BEST performing/most powerfull P&W engine that could have historically been installed in the P36 in late 1941 or early 1942 in time for the P36 to see combat at say Midway and Guadalcanal? What is your best guess on the performance of the P36 with your historical engine of choice with 2 synchronized 50's for armament?

  14. #44
    Senior Member GrauGeist's Avatar
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    Quote Originally Posted by pinsog View Post
    What is the BEST performing/most powerfull P&W engine that could have historically been installed in the P36 in late 1941 or early 1942 in time for the P36 to see combat at say Midway and Guadalcanal? What is your best guess on the performance of the P36 with your historical engine of choice with 2 synchronized 50's for armament?
    You'd be better off getting rid of the syncronized cowl weapons...too low of a rate of fire. Four .50 or six .30 wing-mounted MGs would be a better choice.

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  15. #45
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    Quote Originally Posted by GrauGeist View Post
    You'd be better off getting rid of the syncronized cowl weapons...too low of a rate of fire. Four .50 or six .30 wing-mounted MGs would be a better choice.
    I would normally agree with you, especially in the european theater, but against Japanese fighters and single engine dive bombers and torpedo planes I don't think it would have been too much of an issue. My school of thought is with the limited amount of engine power available in 1941 and 1942: I would rather have 2 50's and be behind the Japanese fighter, than have 4 or 6 50's and he is behind me. Also, the SBD Dauntless only had 2 synchronized 50's, I know it was a dive bomber, but still. (Does anyone know the rate of fire of the Dauntless's synchronized guns?)

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