Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: awrabbit on January 04, 2009, 10:26:55 AM
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Hiya Folks.
I was watching the military channel last night and the show great planes was on they were talking about the P40 and said that the British only would order the plane if it had the merlin in it?
I didnt know this and it sparked my interest about how did it perform with the Merlin?
As it was way under powered with the allison. I always thought that with a more powerful engine it would be a pretty decent fighter.
Also in the show they said that the P-40's that the AVG received were built for the RAF but, I am pretty sure that these were equipped with the allison. I figured that some of you P-40 fans out there would have more info on this and could set the record straight.
What would be the performance differences with the allison equipped P-40 and the merlin equipped P-40.
If the merlin was used on this plane did they use the 2 speed super charger ? which would make the plane of course have a better service ceiling and more speed. ( anyone have any data ?)
also they stated the the allison for the p-40 was not supercharged. did they ever use a super charger on this aircraft? If so how did it perform ? how did the addition of the merlin change the over all balance of the air frame? I would have to think that the service ceiling would have increased by a ton and it would of had a much inproved climb rate. It would be interesting to see the data.
I hate it when some of these programs that are supposed to be hilighting a particular air craft and they do not go into enough detail on the important aspects of what made it such a great plane. instead of giving us more information they leave us with more questions. but, still it is nice to see a program about any WWII aircraft. it would be interesting to see more shows about all of the lend lease aircraft and how they were used and performed in the war. From what I understand the Russians loved the P-39's as well.
Regards
Rabbit
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this is some of the info I came up with..... crap ! I hate when I post before i have had my first cup of coffee ! :D
In 1941, P-40D Ser No 40-360 was fitted with a 1300 hp British-built Rolls-Royce Merlin 28 engine with a single-stage two-speed supercharger. It flew for the first time on June 30, 1941. This experimental P-40D could be distinguished from the stock P-40E by the absence of the top-mounted carburetor air scoop. The Merlin engine did much to overcome the limitations imposed by the Allison, and a total of 1311 examples powered by the American-made version of the Merlin that was built by the Packard Motor Car Company were ordered under the designation P-40F.
The P-40F and later versions were known by the name *Warhawk* in US service.
The first 699 planes of the P-40F series had no dash numbers, since the production block designation system was not yet in effect. The dash numbers were first used with the P-40F-5-CU model, which introduced a fuselage elongated from 31 feet 2 inches to 33 feet 4 inches in order to improve directional stability. This longer fuselage was retained in all later P-40 versions. The P-40F-10-CUs had manual instead of electrically-operated cowl flap controls. The P-40F-15-CUs had winterizing equipment, and the P-40F-20-CUs had a revised oxygen flow system for the pilot. A radio mast was fitted to late production P-40Fs.
The P-40F was powered by a Packard-built Merlin V-1650-1 twelve-cylinder Vee liquid-cooled engine rated at 1300 hp for takeoff and 1120 hp at 18,500 feet. Maximum speed was 320 mph at 5000 feet, 340 mph at 10,000 feet, 352 mph at 15,000 feet, and 364 mph at 20,000 feet. An altitude of 10,000 feet could be attained in 4.5 minutes, and an altitude of 20,000 feet could be reached in 11.6 minutes. Maximum range was 700 miles at 20,000 feet (clean), 875 miles (one 43 Imp gal drop tank), and 1500 miles (141.5 Imp gal drop tank). Service ceiling was 34,400 feet. Weights were 6590 pounds empty, 8500 pounds normal loaded, and 9350 pounds maximum. Dimensions were 37 feet 4 inches wingspan, 33 feet 4 inches length (P-40F-5-CU and later), 10 feet 7 inches high, 236 square feet wing area. Armament consisted of six 0.50-inch machine guns in the wings.
One hundred and fifty P-40Fs were supplied to the RAF under Lend-Lease. The RAF assigned them the name Kittyhawk II. The Kittyhawk IIs were offset from USAAF allocations 41-13697/14599. RAF serials were FL219/448. Unfortunately, P-40Ls were also mixed in with this lot with no mark distinctions, so it is impossible to tell which planes were Fs and which were Ls by merely looking at the RAF serial number. In the event, very few of these aircraft actually served with the RAF. FL273 and FL369-448 were returned to the USAAF for use in North Africa in 1942/43. FL230/232, 235, 236, 239/240 were lost at sea before reaching the RAF. FL263, 270, 276, 280, 383, 305, and 307 were handed over to the Free French, who operated them in North Africa. 100 were transferred to the USSR.
The designation YP-40F was unofficially assigned to P-40F Ser No 41-13602 used for experimental tests of the cooling system and the tail rudder. The coolant system was moved aft in several different configurations, including a mounting fitted inside a thickened wing-root section.
USAAF serials of the P-40F were as follows:
41-13600/13695 Curtiss P-40F Warhawk
41-13696 Curtiss P-40F Warhawk (order cancelled)
41-13697/14299 Curtiss P-40F Warhawk
41-14300/14422 Curtiss P-40F-5-CU Warhawk
41-14423/14599 Curtiss P-40F-10-CU Warhawk
41-19733/19932 Curtiss P-40F-15-CU Warhawk
41-19933/20044 Curtiss P-40F-20-CU Warhawk
A number of P-40Fs were selected at random, withdrawn from operational service, and fitted with Allison V-1610-81 in place of their original Merlins. These planes were intended for training duties. These were redesignated P-40R-1. Similar conversions from the P-40L were designated P-40R-2. Army records report that over 600 such conversions were made, but only 70 such conversions can be confirmed by serial number
Here is the link for all of the information: http://home.att.net/~jbaugher1/p40.html
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I really don't know a whole lot about P-40s equipped with Merlins but from what i'm told it didn't make a huge difference
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The Allison V-1710 was equipped with a two stage single speed crankshaft driven centrifugal supercharger. As such, it could only be tuned for peak power for one narrow altitude range. The gearbox that drives the supercharger would have a gear ratio selected to produce the correct boost for a given altitude. There were proposals to equip the V-1710 with a two speed two stage supercharger, but it was never done. The P-38 solved the problem with a turbocharger. It complimented the supercharger by adding the boost necessary to maintain sea level performance to a very high altitude, and a waste gate prevented the turbocharger from over boosting the engine.
Aircraft engines of the day, especially inline Vee types, were very low compression, usually in the 5.5:1 zone. Without supercharging they'd have never been able to produce even a 1/2 HP per cubic inch. So without a supercharger, a 1650 Merlin would make 825HP or less, and a 1710 Allison would make 855HP or less. There'd have been no need for high octane fuel either, as a 5.5:1 compression ratio, unsupercharged, would run on 80 octane or less.
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Don't listen to what that crap show says anyway, I dunno who writes and edits it, but they're idiots. Just in the P-40 show, for example- they were talking about the development of the P-40 from the P-36... while showing pictures of the North American P-51 protoype, claimed that the P-39s nose armament was one 37mm cannon (which it was) and four .30 MGs (which were in the wings, the nose was 2 .50s), and talked about the Brits "only" accepting P-40s if they had a Merlin, when they had large numbers of Allison-engined P-40Bs and Es (which they called the "Tomahawk" and "Kittyhawk") long before the Merlin-engined F was a gleam in Curtis' eye.
Between the horrible research and the insanely boring host who obviously has to attempt to memorize and practice all the inane and pointless questions he asks, I have no idea how that show ever got picked up. In fact, as bad as "Showdown" was, I can't figure out how they gave that guy another show to host. Is he related to the programming director or something?
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There were a couple of P40 variants with single stage Merlins. Ironically they were flown by USAAF units in North Africa while the RAF squadrons flew Allison versions.
There were some Merlin P40s used in the PTO as well on the Canal and elsewhere. You can spot a Merlin P40 by the lack of air intake on top of the nose.
It was not a British specific order by any means as I don't believe they got many. I think I've seen one photo of an RAAF operated Merlin P40.
THe Merlins were being built under license in the US
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Don't listen to what that crap show says anyway, I dunno who writes and edits it, but they're idiots. Just in the P-40 show, for example- they were talking about the development of the P-40 from the P-36... while showing pictures of the North American P-51 protoype, claimed that the P-39s nose armament was one 37mm cannon (which it was) and four .30 MGs (which were in the wings, the nose was 2 .50s), and talked about the Brits "only" accepting P-40s if they had a Merlin, when they had large numbers of Allison-engined P-40Bs and Es (which they called the "Tomahawk" and "Kittyhawk") long before the Merlin-engined F was a gleam in Curtis' eye.
Between the horrible research and the insanely boring host who obviously has to attempt to memorize and practice all the inane and pointless questions he asks, I have no idea how that show ever got picked up. In fact, as bad as "Showdown" was, I can't figure out how they gave that guy another show to host. Is he related to the programming director or something?
I relatively enjoyed Showdown Aircombat. They just made the graphics cheesy. I watched a lot of the P-40 show, and I liked it.
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Both the P-40F and P-40L were powered by the Packard built V-1650-1 Merlin.
P-40F: 1,311 delivered
P-40L: 1,300 delivered
Except for the first P-40F-1-CUs delivered, all Merlin powered P-40s were "long tail" types (extended tail).
Note that the Merlin offered slightly better mid altitude performance, making best speed about 5k higher than the P-40E. Max speed and climb rate differed little, if at all.
In the desert of North Africa, the Merlin powered P-40s required more maintenance than the Allison models. Largely due to the Merlin's bottom breathing carburetor sucking in far more dust and sand (F and L models don't have the carburetor intake above the engine as does the Allison P-40s). Pilots stated that the Merlins were more difficult to manage than the Allison as they required more attention relative to cylinder head and coolant temperatures. Merlins had a greater tendency to overheat, especially while running on the ground.
My regards,
Widewing
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Yup, I watched those "Greatest Ever: Planes" show last night. chuckled when they used the same plane as the so called "P-40 prototype, and the P-51 prototype"
I also thought Showdown was a bust.
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I stumbled across a website either on the USAF or a museum webpage network, and folks could leave comments on the sub-pages. On the P-40 page there was very little info, but somebody asked if there was much difference between the versions. Somebody replied saying they had flown them in the PTO and there wasn't any noticable difference between the Merlin/Allison versions. Said there wasn't any noticable difference until the N model.
Anecdotal, but from somebody that claimed to fly 'em in WW2.
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Both the P-40F and P-40L were powered by the Packard built V-1650-1 Merlin.
P-40F: 1,311 delivered
P-40L: 1,300 delivered
Except for the first P-40F-1-CUs delivered, all Merlin powered P-40s were "long tail" types (extended tail).
Note that the Merlin offered slightly better mid altitude performance, making best speed about 5k higher than the P-40E. Max speed and climb rate differed little, if at all.
In the desert of North Africa, the Merlin powered P-40s required more maintenance than the Allison models. Largely due to the Merlin's bottom breathing carburetor sucking in far more dust and sand (F and L models don't have the carburetor intake above the engine as does the Allison P-40s). Pilots stated that the Merlins were more difficult to manage than the Allison as they required more attention relative to cylinder head and coolant temperatures. Merlins had a greater tendency to overheat, especially while running on the ground.
My regards,
Widewing
The USAAF carrier launched P40s during Operation Torch were all Merlin birds with the 33rd, 57th and 79th FGs that flew them until they transitioned to Jugs. The 325th also had Merlin P40s if memory serves.
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Here is a topic on another forum im on dealing with the powerplant of the P-40.
http://www.ww2aircraft.net/forum/aviation/fun-wwii-what-if-16105.html
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Allison engined P-40 with the intake on top
(http://i152.photobucket.com/albums/s199/guppy35/Allison.jpg)
Merlin engined P40 without the intake on top.
(http://i152.photobucket.com/albums/s199/guppy35/Merlin.jpg)
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The Allison used a down draught carb while the Merlin used an up draught carb. Therefore, the intakes had to be positioned like they are.
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Wonder how the performance compares. Anyone?
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From what I understand the performance difference is not much different 5 mph and a bit more alt.
I would think that it would have been much improved if was mated with the uber Merlin. from looking around on the net it seems that the merlin was neutered missing its two stage supercharger.
Also why did they run such low compression in those engines ? we had the high octane fuel just by bumping the compression up a few points the engines would have made much more power. 10.5.1 to 13.5.1 the higher number would take atvantage of the higher octane fuel.
Heck, with the compression upped just a bit they could of added 500 to 700 hp and still be with in a safe range to keep them durable as well as perform much more consistant.
Blowers and Turbos make cylinder pressures much more touchy (harder to tune and much harder on parts due to heat/stress. I have seen blowers lift the heads off from engines and also fracture cylinders, as well blow the top ring lands completly off the tops of the pistons. if they had wanted they could have then used the superchargers at very low boost ranges for even more output. But, I am getting off topic about the P-40 and on to the potential of the engines that was used in the air plane. (Strega just popped into my head but that little merlin is hopped up to to the edge of being a bomb.
I am not thinking nowhere near the kind of power those guys are making it is way too on the edge ! )
But, thinking about the what ifs' wonder how it would have been with the hair dryer( the turbo charger ) on the allison? Or, it had the same two stage merlin as the 51 ?
I would speculate to say that it would have been like a F6F or a Hurri ? the air frame appeared to be pretty sound for the most part.
Would kinda cool to see what a bubble canopy on the P-40 and the lines cleaned up a bit would look like. Perhaps one of the many artists here on the boards could draw one like that.
Rabbit
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That would be the P-40-Q prototype. Actually, there were 4 different -Q's, but one had the bubble canopy and cleaned up fuselage. I have a book with some photos, but I have found these images online that are comparable:
(http://www.aviastar.org/pictures/usa/curtiss_p-40q.jpg)
(http://www.swannysmodels.com/images/P40Q/boxart.jpg)
And here's a nice shot from Wikipedia: http://commons.wikimedia.org/wiki/File:P-40Q.jpg
-Llama
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It is still common practice when seeking the maximum horsepower to run a lower compression ration and more boost. These days, 7:1 or 8:1 is what we call low. They weren't too far off back then. Ever look closely at an Allison V-1710 engine? Dual overhead camshafts, roller rockers, 4 valves per cylinder, forged pistons, forged rods, forged crank, dual spark plugs in each cylinder, not bad for an engine designed to move blimps around in the thirties. The later Allisons did have slightly higher compression.
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So, a Merlin powered P-40 vs a Allison powered P-40 there and then, side by side, performance comparison?
Out of memory, they started sucking above 15K and were therefore applied more in the ground roles, and I do recall that Hurricanes (Yes) were used as escort!
So, was the Merlin clapped in for giving them at least a decent performance at 20K or better ROC, or what? why?
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The P-40Q was an experimental project which attempted to produce a really modern fighter out of the existing P-40. The modifications were in fact so drastic that there was very little in common with earlier P-40 versions.
Two P-40Ks (serial numbers 42-9987 and 42-45722) and one P-40N (serial number 43-24571) were extensively modified with revised cooling systems, two-stage superchargers, and structural changes which markedly altered their appearance. The project was assigned the designation XP-40Q.
The first XP-40Q was P-40K-10-CU ser no 42-9987 fitted with a new cooling system, a longer nose, and a four-bladed propeller. The radiators were moved into an under-fuselage position, with intakes between the undercarriage legs.
The most prominent XP-40Q feature, used on 42-45722 and 43-24571, was the cutting down of the rear fuselage and the addition of a bubble canopy as on the "XP-40N". Later the wingtips were clipped. The result was an aircraft which bore almost no resemblance whatsoever to its parent P-40 line. The V-1710-121 engine was fitted with water injection, resulting in a power of 1425 hp. Speed increased to 422 mph at 20,500 feet, making it the fastest of all the P-40s. An altitude of 20,000 feet could be reached in 4.8 minutes, and service ceiling was 39,000 feet. Four 0.5-inch machine guns were carried by the prototypes. Wingspan was 35 feet 3 inches (after clipping), and length was 35 feet 4 inches (2 feet longer than the P-40N).
The proposed production models of the P-40Q were to have carried either six 0.50-inch machine guns or four 20-mm cannon, but the XP-40Q was still inferior to contemporary production Mustangs and Thunderbolts, and development was therefore abandoned. Consequently, the production life of the P-40 ended with the N version.
The second XP-40Q was briefly used for postwar air racing. Registered NX300B, the second XP-40Q was an unauthorized starter in the 1947 Thompson Trophy race. It was in fourth place when it caught fire and had to drop out of the race.
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I've been doing some research on the P-40L (Merlin and less weight) which the 332nd flew in North Africa. As far as performance the L was not much faster than the previous versions (5mph or so). However, the L only had 4 .50's and they removed about 200 lbs of armor from around the engine so it was much more maneuverable. The standing orders from the 33rd Fighter Group (witch the 332nd was initially part of) was to turn into the enemy and keep them turning. At medium to low altitude, the P-40L would easily out turn the Fw190s, Bf109F's and G's (from Bucholtz "332nd Fighter Group") When any P-40L tried to run they were easy targets, as the Germans were much faster.
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Very interesting information about the P-40 indeed.
I think the Q model looks great ! too bad it get to that point of development till the very last or, the P-40 would have played a much more significant roll in the war other than being fighter to fly because nothing else was available.
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Me thinks the P40 platform would have lived longer, regardless of the P51/P47, if the politics would not have been involved.
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P-40 probably wouldn't have lived as long as it did had politics not been involved. Despite all their problems, Curtis had some good lobbyists.
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It is still common practice when seeking the maximum horsepower to run a lower compression ration and more boost. These days, 7:1 or 8:1 is what we call low. They weren't too far off back then. Ever look closely at an Allison V-1710 engine? Dual overhead camshafts, roller rockers, 4 valves per cylinder, forged pistons, forged rods, forged crank, dual spark plugs in each cylinder, not bad for an engine designed to move blimps around in the thirties. The later Allisons did have slightly higher compression.
we used to run an Allison powered 4X4 pulling truck, dual mags as well, external 4 cylinder blower ( not pictured) and the front gear driven one, ours coughed one time in California ( one mag drive broke) spit out both drivelines about halfway down the track 1/4 inch sidewall tubing, looked like a crumbled up drinking straw
(http://i249.photobucket.com/albums/gg229/WWhiskey/v-12.jpg)
sorry but i don't have any good pictures on line of this truck yet !