WW2 without V-1710: options for the Allies?

[wuzak]

Yeah, Wuzak, I consider 2,200 P-40's to be a drop in the bucket compared with the rest of the US fighters produced for WWII. Plus or minus that many would have made ZERO difference to the USAAF.

But, I would figure that when they were built the 2,200 P-40Fs and Ls would have formed a significant proportion of the fighters produced in the US. They were produced over a relatively short time frame, but made up 16% of P-40s produced.

If the Allison wasn't around, for whatever reason, there would have been more Merlin P-40s.

The USAAC/F wanted liquid cooled fighters.

And, as you said, the P-40 wasn't exactly a front-line plane anyway.

That's not what I said.

The fact is that, at least for the early war years, the P-40 was a front-line fighter, and the best the USAAF had.

No, without the P-51, the Merlin would have been essentially a non-starter for US production of fighters.

I disagree. The Army had the contract with Rolls-Royce and Packard such that some of the production was for US aircraft. They wouldn't be used for trainers, GA aircraft, bombers or Navy planes, they can only have been for USAAF fighters. And the P-51, let alone the Merlin P-51, didn't exist.

We'd have gone all-radial or would have developed an alternative engine.

There was a reason why the USAAF had the contract between Packard and Rolls-Royce specify that 1/3 of production would go to US aircraft. They wanted liquid-cooled engines for US fighters, based on observations of the air war in Europe. And it helped the USAAF pressure Allison into doing a better job.

The USAAF did not want an all-radial fighter fleet. Some programs were specified with the V-1710 as the engine. If the V-1710 engine had failed or been terminated at that point they would have been looking for a replacement engine. And the Merlin would have fitted best.

As for developing alternatives, you would have to say other attempts at US liquid cooled aero engines during WW2 were failures. Some flew, but none went into series production. The Allison was the only use liquid cooled type to see series production.

 

[GregP]

Nope, would NOT have happened without the P-51.

You aren't from here and do not realize the political reality of the time. My mom and dad were FROM that time, along with most of their friends, and it would NOT have happened.

Since this is a contrived what-if, let's let it go, OK?

 

[wuzak]

Nope, would NOT have happened without the P-51.

You are saying that without the P-51 the 1/3 of Merlin production licence production required by contract would not have gone into anything else? Even though that term was made in 1940, before the existence of the P-51?

If they didn't intend to use them, why did they demand a proportion for their own use (and not just one or two for experimental purposes).

 

[GregP]

As a fallback in case.

 

[wuzak]

As a fallback in case.

In case....the Allison V-1710 didn't work?

Would it stand to reason, then, that the US would have aircraft designed with the V-1710 changed over to Merlins - P-38, P-39, P-40, P-51 - and that the licence production would have been ramped up (in facilities that the V-1710 was to use as well as Packard) in the scenario from the OP?

 

[GregP]

Wuzak, I asked you to let it go.

DO IT dammit.

It does not stand to reason in the 1940 timeframe except from an outside viewpoint (which I agree with today).

 

[wuzak]

Wuzak, I asked you to let it go.

Ok, letting go....

 

[Shortround6]

Maybe there would be a move to develop a Lycoming or license-built RR, BMW or DB V-12 modification of the P-36 that resulted in license production of a foreign engine? Weren't the initial Bf-109s powered by RR engines? So once the idea of a P-36 with a liquid cooled engine is floated, the provider becomes who ever is building a possible engine, no?

The Lycoming engine was too small (not to the Army's eyes at the time) and as it existed was a "flat" engine, it could have been been bent into a "V" but that adds a bit more time. It was a 1234 cu un ( 20.2 L) engine, smaller than a Kestrel or Peregrine and depended on high rpm and high boost to make it's power. It used a short stroke so the RPM may not have been a big problem.
The German engines are pretty much non-starters unless you really push history, Not so much from the "Not invented here" stand point but from the fact that the DB 601 was pretty much "vapor ware) as far as the rest of the world was concerned in 1938. At the Paris Air show/exhibition in Dec 1938 the DB 601 was talked about but NOT displayed. RR had a Merlin X (two speed supercharger) on display and was talking about hp figures using 100 octane fuel. Information on large German engines was sketchy, to say the least. People to not take out licences on engines they don't know about. The Only BMW V12s were the old one that was pretty much two WW I straight sixes on a common crankshaft and a small experimental built to compete with the Jumo 210.
A single 109 was powered by a RR Kestrel because the Jumo 210 had not been cleared for flight at the time. This one Kestrel may have made the "rounds" and powered not only the first JU 87 but another prototype as well.

Alternatively, the army would have a variety of radial development options although it might have resulted in an odd mix of a/c operational on December 7, 1941. The US army could have subjected to further development and ultimately bought more upgraded P-36s and P-43s and perhaps land based F4F-3s or P-66s by December 7th, 1941 with perhaps a strictly land-based USAAF F4U variant in the wings or instead of the P38 perhaps the USAAF might push development of the Grumman XP-50 (first flight 2/18/41).

The upgraded P-36 is a possibility but it is still well behind the world standard. Production P-36s had single speed superchargers and about 1050hp for take-off. Later (1941) R-1830s got 2 speed superchargers and other improvements and not only had 1200hp for take off but were allowed 1200hp at 5,000ft, and 1050 at 13,100ft Military ratings. Any improvement after that had to wait several more years. Vought built 178 F4us in 1942, and Land Based modification is a non-starter. Land based F4Fs and P-66s hit the engine problem too. You can't take enough weight out of the F4F to make a real difference without redesigning the whole thing and P W had trouble making enough two stage engines as it was which is why there was a F4F-3A model with two speed SINGLE stage supercharger whose performance was a little less than thrilling at altitude. FTH was 5-6,000 ft lower than than the F4F-3.
US might push development and production of the XP-50 but since it was destroyed early in the test program it's published numbers must be looked at with a fair degree of suspicion as the XF5F missed it's estimated numbers by a fair margin. US had problems with turbo controls on ALL it's turbo charged aircraft in the early part of the war.
P-43s come ONLY at the expense of the P-47 program. How big an expense depends on how and when you play with the program. Sept 13 1940 had the US Army place an order for 773 P-47s off the drawing board after they decide the proposed (and mocked up) liquid cooled P-47A is a non-starter.

I would expect the state of the US a/c industry would have inspired the BPC to go around to a number of manufactures asking them to produce something, anything but what they were currently building for the USAAF and the P-51B would have been born earlier or maybe USA built Hurricanes or Spitfires or lots and lots of Boulton Paul Defiants. Or best of all, the army might have obtained thousands of Bell FM-1s aerocudas.

The BPC was limited as to what they could order. The US had gotten burned in WW I when it finally declared war and found it's factories were tooled up for an assortment of foreign weapons it didn't want and had a hard time using. IF the US PTB (powers that be) thought a foreign design was acceptable to the US Military it would be given the OK for production, if not then no production. No US company made a British tank design and the US had squat for tanks at the time. There was a set of standards for US military aircraft at the time that covered a bunch of things aside from the actual performance numbers, standards for stress loadings, landing impacts, construction details (fittings and such). The US did not what a bunch of factories tooled up and producing Whitworth nuts, bolts, fittings and such.

For all its faults, I don't think the world is necessarily better off without the Allison.

I think that is a little harsh, the only real fault the Allison had was the lack of a really good supercharger between late 1940 and 1943/44. It's supercharger was no worse than the German ones in 1940-41-42. The Germans just didn't try to power 7,500-8,500lb planes with 1200hp engines. Blaming the engine doesn't seem quite fair.

 

[Glider]

If the Allison hadn't been around and the USAAF wanted a liquid cooled engine then there only seem to be two real options, to license build either the Merlin or the DB601/5.

The risk involved in a rushed development of a new liquid cooled engine with war looming and no time for second guesses if there was a problem with the primary option, would seem to rule any other options out.

Its only a guess but if the Alison hadn't been available the US would have stuck to radial engines which they had in quantity and quality.

 

[Shortround6]

The DB 601-605 is pretty much a non-starter. The Germans are not trying to actively export it even in Dec of 1938 let alone licence it to any but the most trusted allies. After Sept 1939 the only option to is use captured examples and try to reverse engineer it. This requires co-operation of the British and French to ship captured examples to the US for examination. Possible but a long difficult process. It took Packard 1 1/4 years to deliver the 5th production Merlin with a pair of sample engines, full drawings and the services of two senior Rolls-Royce engineers and a stream of communications to the home factory.

The Allison powered 792 aircraft delivered in 1940, 3519 delivered in 1941 and around 6600 in 1942. Packard averaged 800 engines a month for the last half of 1942.

Any substitute for the Allison has to start in 1939 or there will be thousands fewer fighter aircraft delivered by the end of 1942 even if the US catches up after that.

 

[drgondog]

Nope, would NOT have happened without the P-51.

You aren't from here and do not realize the political reality of the time. My mom and dad were FROM that time, along with most of their friends, and it would NOT have happened.

Since this is a contrived what-if, let's let it go, OK?

So, your mom and dad were the secret consultants to Hap Arnold and presumably convinced General Arnold that there was no place in the USAAF planning for a high performance, fuel efficient Liquid Cooled engine in the USAAF inventory - if there was no other option, nothing in the pipeline? And compound the stupidity despite being tooled up for it and presumably be available to ramp up production?

In your opinion Arnold then turns to the USN and purchases the F4U rather than use a Brit Hybrid engine in a USAAF specified airframe?

So, your opinion is that Arnold was stupid? Seems to be a siilly opinion.

 

[swampyankee]

I second the motion.

The best engine solution was staring U.S. Army Air Corps in the face. Just need to be smart enough to recognize it.

yup. It came from companies called Wright and Pratt&Whitney: radials.

 

[Shortround6]

The never much liked (in some 'camps') Allison V-1710 powered many US-built fighters, flying in all the war theaters, especially until sufficient number of the Thunderbolts and Merlin Mustangs were in service. So let's say, for the sake of discussion, that somehow people at Allison really messed up their machine, so the USAF Allies must acquire it's fighters without it. What would be the best alternatives, ie. historical engines set-ups, for the USA/USAF in order to produce/purchase it's fighters both in quality and quantity, until the P-47C and P-51B arrive to the scene.

going back to the Original question it depends on When Allison "messed up their machine".

Without the Allison the P-39 is pretty much done ( Wright cyclone powered P-39

Maybe you can build a special model Merlin. The DB 601, Continental IV-1430 and Lycoming O-1230 need not apply. They need gear sets to lower the the drive from the crankshaft to pass under the pilots sear and another gear set to bring the drive back up to the propeller. On the two American engines you have length problems to boot.

Get Bell to licence what? P-36s? P-43s? The vast majority of US fighters built before the end of 1942 were powered by Allison engines, 2nd most used engine was the R-1830 in the F4F and strange as it may seem they built roughly the same number of F4Fs by the end of 1942 as the did Merlin powered P-40s, or within a hundred or so. Massive expansion of P&W factories even earlier? While a P-40 test mule with a R-1830 did beat the performance of the Merlin Powered P-40 it wasn't until the fall of 1942 that it did so and the plane was unarmed.

Wright R-1820s seemed to have troubles as fighter engines in 1940-42. Problems with oil distribution while maneuvering?

If Allison stuffs it up soon enough maybe Packard can resurrect one one of their old engines but I believe their chief designer had died in an air crash in 1930(?) so some of the later engines were just derivatives of late 1920s designs.
Try to use the PT-boat engine?

 

[oldcrowcv63]

I guess it was late at night after a long and frustrating day resulting in my being a little too flip (especially in the nonsensical Aerocuda comment) with what I thought and think is a really interesting question. Even so, I appreciate your taking each comment seriously and elaborating on the prospect and consequences. I thought, and agreed after posting, that my last comment on the Allison was indeed a bit harsh.

The Lycoming engine was too small (not to the Army's eyes at the time) and as it existed was a "flat" engine, it could have been been bent into a "V" but that adds a bit more time. It was a 1234 cu un ( 20.2 L) engine, smaller than a Kestrel or Peregrine and depended on high rpm and high boost to make it's power. It used a short stroke so the RPM may not have been a big problem.

It seemed that the primary historical benefit of the early existence of the Allison were the roughly parallel developments of the P-37, -39 -40 and the P-38. and their production in late 1941 in sufficient numbers to provide an immediate core USAAF force for use in the coming war and to supply the even earlier requirements and needs of allied air forces.

Trying to extrapolate the effect of the void existing due to the Allison's absence during a period when liquid-cooled engines seemed to be worth pursuing in a major way, I wondered whether the domestic engines that were in the shadow of the Allison might have received more developmental attention and come out of that process as better than they historically did. In other words, was the Allison analogous to the dinosaurs that prevented the emergence of higher mammalian species. Remove the dinosaurs and mammals flourish. Does, removing the Allison open the way to improving the Lycoming O-1230 or Continental I-1430, allowing them to evolve into some more suitable variant? Is the time frame just insufficient to have that happen or are their inherent deficiencies in the design of each that no amount of development would resolve. It seems you (SR6) see evidence that was the situation and they would not be suitable surrogates.

If the P-40 and other a/c are to come into existence in a scenario where no domestic liquid-cooled engine meets the required need, then is their a foreign product that might allow that to proceed in something like a historical fashion. I thought, British, German, and probably should have included the Hispano-Suiza 12Y, as well as Russian AM35 as options, no matter how unlikely.

If no foreign product is suitable, then it would seem the USAAF is limited to Radials of equivalent power. To simply get to numbers that are roughly equivalent to the number of P-40s produced in a comparable time frame, it would seem that extending both the development and the production runs of the P-35 P-36 is nearly the only option. The only other aircraft that seems comparable and roughly in accord with an early development and production (albeit engine and factory floor space limited) would be an army variant of the F4F-3A or F2A whose development would have had to be in parallel to the USN's forcing major, early expansion in the Grumman iron works Brewster's problematic industrial capability .

As intermediate stop-gaps, perhaps additional development of the P-43 to most quickly overcome the foreign performance gap, perforce accepting a delay in the P-47 and in desperation even considering an army F4U seem like later possibilities. None of the latter help our allies in the short run, so without an allison powered P-40 they are left with a number of very unsatisfactory options motivating them to consider some very (historically) unorthodox possibilities including early development of the P51B. At least that was the train of thought.

Based upon your answer it seems that lack of the Allison puts both the USAAF and allied air forces at a considerable disadvantage.

 

[swampyankee]

I guess it was late at night after a long and frustrating day resulting in my being a little too flip (especially in the nonsensical Aerocuda comment) with what I thought and think is a really interesting question. Even so, I appreciate your taking each comment seriously and elaborating on the prospect and consequences. I thought, and agreed after posting, that my last comment on the Allison was indeed a bit harsh.



It seemed that the primary historical benefit of the early existence of the Allison were the roughly parallel developments of the P-37, -39 -40 and the P-38. and their production in late 1941 in sufficient numbers to provide an immediate core USAAF force for use in the coming war and to supply the even earlier requirements and needs of allied air forces.

Trying to extrapolate the effect of the void existing due to the Allison's absence during a period when liquid-cooled engines seemed to be worth pursuing in a major way, I wondered whether the domestic engines that were in the shadow of the Allison might have received more developmental attention and come out of that process as better than they historically did. In other words, was the Allison analogous to the dinosaurs that prevented the emergence of higher mammalian species. Remove the dinosaurs and mammals flourish. Does, removing the Allison open the way to improving the Lycoming O-1230 or Continental I-1430, allowing them to evolve into some more suitable variant? Is the time frame just insufficient to have that happen or are their inherent deficiencies in the design of each that no amount of development would resolve. It seems you (SR6) see evidence that was the situation and they would not be suitable surrogates.

If the P-40 and other a/c are to come into existence in a scenario where no domestic liquid-cooled engine meets the required need, then is their a foreign product that might allow that to proceed in something like a historical fashion. I thought, British, German, and probably should have included the Hispano-Suiza 12Y, as well as Japanese and Russian options, no matter how unlikely.

If no foreign product is suitable, then it would seem the USAAF is limited to Radials. If only radials of sufficient power are available then to simply get to numbers equivalent to that of the number of P-40s produced in a comparable time frame, it would seem that extending both the development and the production runs of the P-35 P-36. The only other aircraft that seems comparable and roughly in accord with an early development and production (albeit engine and factory floor space limited) would be an army variant of the F4F-3A or F2A whose development would have had to be in parallel to the USN's forcing major, early expansion in the Grumman iron works Brewster's problematic industrial capability .

As intermediate stop-gaps, perhaps additional development of the P-43 to most quickly overcome the foreign performance gap, perforce accepting a delay in the P-47 and in desperation even considering an army F4U seem like later possibilities. None of the latter help our allies in the short run, so without an allison powered P-40 they are left with a number of very unsatisfactory options motivating them to consider some very (historically) unorthodox possibilities including early development of the P51B. At least that was the train of thought.

Based upon your answer it seems that lack of the Allison puts both the USAAF and allied air forces at a considerable disadvantage.

With the last sentence, I disagree: the engines from Pratt&Whitney and Wright were quite capable of providing power for world-beating fighters. USAAF preference for liquid-cooled inlines was more due to fashion (they looked more streamlined, more modern) than to aerodynamics (the zero-lift drag coefficient of almost all fighters ranged between 0.02 and 0.025, whether powered by in-lines or radials: the Spitfire and the Corsair had quite similar zero-lift drag coefficients). There were also, of course, development efforts that were not being heavily funded, like the "Hyper" project, that could have been funded more heavily, and there were liquid-cooled engines under development by Wright and P&W.

 

[oldcrowcv63]

With the last sentence, I disagree: the engines from Pratt&Whitney and Wright were quite capable of providing power for world-beating fighters. USAAF preference for liquid-cooled inlines was more due to fashion (they looked more streamlined, more modern) than to aerodynamics (the zero-lift drag coefficient of almost all fighters ranged between 0.02 and 0.025, whether powered by in-lines or radials: the Spitfire and the Corsair had quite similar zero-lift drag coefficients). There were also, of course, development efforts that were not being heavily funded, like the "Hyper" project, that could have been funded more heavily, and there were liquid-cooled engines under development by Wright and P&W.

I was really concerned with the time factor here wherein the radials producing power for a/c like the F4U and P-47 haven't yet arrived in sufficient numbers nor have the associated a/c to make a difference.

 

[Shortround6]

The knowledge of how to cowl a radial engine was in it's infancy in 1938-40. The P-40 showed a 22% reduction in drag over a P-36. A gain of about 30-40mph in speed using similarly powered engines. This was NOT just fashion or looks. By late 1942 they had it pretty well sorted out and prototype radial engined aircraft could match the liquid cooled engines for drag pretty well but that is way too late for deployed combat planes in 1941/42.

Using exhaust thrust was also a problem on radial engines. Most radials used an exhaust collector and one or two exhaust outlets which often did NOT direct the exhaust rearward or mostly rearward. Some radial installations tried, like the B-25 with 14 lumps on each cowling over individual exhaust stacks but the drag on that is rather suspect.

Oldcrowcv63 is quite correct on the timing of the higher powered radials. Allison built 6400 engines in 1941. P W built 1461 1850hp single stage R-2800s in 1941, over 1000 of them in the last 1/2 of the year. 2 2000hp single stage engines and 6 2000hp two stage engines. Ford had built 264 R-2800s, all single stage engines.
The only High powered radial (over 1200hp) available in real numbers for most of 1941 was the Wright R-1600 "A" series engine of 1600hp take-off and 1400hp at 11,500ft. Most of it's extra power is going to get sucked up by it's extra weight and drag.

The Hispano 12Y series wasn't a good option.
The two Hyper engines had been crippled by Army design choices. They used small cylinders and high rpm which allowed for a high BMEP at the time but they also used separate cylinders instead of cylinder blocks which made for long engines for their displacement, they were at least as heavy as larger displacement, comparably powered engines. The separate cylinders also made for a weaker engine even if they did use a common cylinder head/cam box design.
The Wright liquid cooled engine was rat hole that makes the Jumo 222 look good.
P W asked to be let go from the liquid cooled engine development as they thought they could get the R-4360 into service before any of the liquid cooled projects. It took them 3 years to get to the 5th R-4360.

 

[GregP]

Apparently you didn't read my posts before throwing sarcasm, Bill.

I said I agreed with the notion to use the Merlin, but the political reality was that the USA wasn't going to use a British engine in a US fighter in 1940 until and unless the war demanded it. In the end we procured some 2,200 P-40F/L models against a total production of some 60,000 fighters from May 1940 thriough August 1945 (and those numbers are missing the last 6 months for the F4F and F6F).

That is about 5% of the US fighter production minus the P-51. If it was a foregone conclusion, why isn't that number higher by a LOT?

If we really needed the Merlin, that percentage would be MUCH higher. There was nothing wrong with the Merlin and there still isn't. But inserting today's opinions into purchase decisions made in early WWII is what sounds silly to me. Mom and dad weren't close to anyone in the position to make WWII decisions, being kids at the time, but they were representative of the people around at the time who weren't flying Merlin-engine Mustangs.

The thread asked what we would do if the Allison wasn't a viable option. I personally have NO issue with the Merlin or anything British or European, but in 1940 America, we'd have used an American engine for American aircraft ... in my opinion.

If you feel differently, that's fine. It is a what-if and there is no right answer since it didn't happen. You are certainly welcome to believe it might have been possible. I just disagree and we'll never be able to find out, will we?

 

[Shortround6]

There is playing with statistics a there is playing with statistics.

In 1942, the year in question, when Merlin Production really got started in the US, the US built 10,090 fighters. Granted the P-40L production didn't start until Jan 1943 but that leaves around 1300-1500 Merlin powered P-40s built in 1942. Or around 13-15% of production for the year. Production of the R-2800 powered planes didn't kick in until the last 4 months of the year and even F4F production didn't top 100 planes a month until May. Total production of F4Fs in 1942 was roughly the same as Merlin powered P-40s. were they a 'minor factor' in US airpower in 1942? There were only 1932 P-39s built in 1942 or roughly 50% more than the Merlin P-40s (and there would have been less of them without the Merlin P-40s).

Allison made 1149 engines in 1940 (year deal was made to build Merlins), 6400 in 1941, 14,900 in 1942 and 21,064 in 1943.

To put things into real perspective by the time the Merlin talks started with Packard Allison had made 3 engines in Jan 1940, 7 in each of Feb, March and April, 14 in May, 30 in June and managed to crank out 73 in July falling to 65 in August.

Not only is having a second source of V-12 engines a good idea but the Allison is an unknown quantity in the summer of 1940, there are not enough in service to KNOW if it is actually going to work or not and in fact there were some problems with the early ones. The first 288 built were operated at reduced power settings while Allison sorted out the problems on the test engines and then brought back the early engines and upgraded them at company expense. In March of 1941 there were only 16 engines left to be reworked.
this compares to thousands of Merlins already built and flown in combat.

Buy "American" might have been popular, it was also stupid given what was going on at the time.

Allison (and GM) performed near miracles in sorting the V-1710 out, getting it into large scale production and developing new, improved models but that was all in the future in the summer/fall of 1940.

 

[beitou]

I don't believe anyone thought of that until both sides wanted to try a Merlin in the P-51. If the P-51 had not come along, I'm not sure anyone would have pursued the license agreement.

Maybe, but maybe not, too.

The USA would not have considered a foreign engine for newly-designed US fighters at the time. It wasn't in the political cards. The only reason it was acceptable for the P-51 is the plane was designed to a British request to start with. If it had come from the USAAF, there very probably would never have been a Merlin engined P-51.

Things back then weren't like they are today, and USAAF / USN planes were all-American items with not a single foreign-produced component.

Of course, we weren't alone there. You didn't see any foreign parts on Spitfires, Hurricanes, Bf 109's Fw 19's, or A6M's either, did you? The only reason the British used some US-made engines and aircraft / components was the necessity dictated by war. Otherwise, fighters were symbols of national pride. May seem strange, but that's the way is was for many centuries, not just during WWI and WWII.

The only reason the Japanese bought some capital ships between WWI and WWII from the UK is they hadn't the skills or equipment yet to build their own. By the time WWII came around, they WERE building their own, including big guns.

Browning machine guns in the UK fighters were a US design.