WW2 without V-1710: options for the Allies?

[Shortround6]

We could have used radials. Predominately the P&W R-1830. Wright R-1820s were a fall back and not a particularly good one in 1939-41.

There were NO viable american liquid cooled engines available in that time period and all the flag waving you want to do does not change that.

You are ignoring the reasons the US entered into that agreement with the British in the first place. In the summer of 1940 the Allison was unproven, having trouble passing it's type test and available in small numbers. The Army's "baby", the Continental I-1430 was no-where near ready for production (and never would be). The Merlin WAS the army's "fall back" plan in case the Allison fizzled. There was NOTHING else available in that category (size and power) and it would take 3-4 years to get something.

Unfortunately the R-1830 was barely competitive in Europe in 1940-41 and falling behind after that. It was somewhat competitive in the Pacific in 1942.
We start getting into the "what if's" of Wright R-2600 powered single engine fighters and those don't look a lot better without "what if-ing " that engine as it never had a good altitude performance and had had questionable reliability at times.

The Allies would have survived but it would have been a much harder, longer battle.

Predicting engine needs (types/numbers/performance) 2-3 years ahead was not easy. Allison came through with new models and with large numbers of engines (unforeseen in 1940?) which coupled with new fuel (also unforeseen) allowing higher boost pressures reduced the "need" for Merlin's in US planes. Last 5,000+ P-40s were either trainers or lend-lease ground pounders and didn't need the performance at 20,000+ ft that the Merlin gave. Changes in priorities may have had more to do with which planes got which engines rather than " we ain't goin ta put no furin ingines in Merican planes" attitude.

 

[GregP]

I simply disagree Shortround. Surprise. If the Allison had failed its type test in 1937, we would have had 4 years to develop another engine or engines. With the units in design, that was certainly possible. Had it been required, we sould have developed any of the engines that were not proeeded with in the time available.

And I am NOT flag waving in the slightest. I already said my personal choice would have been the Merlin. For the last time, it is what I believe the choice would have been at that time given the attitudes in place in the pre-war USA, and that is all it is.

 

[wuzak]

Greg, since a significant proportion of pre-1941 US production is geared towards the export sales to the UK and France would you expect that the attitude towards licence built foreign engines would be different?

Also, failing the type test is not the only way that the Allison goes missing. Allison wasn't very profitable, and GM may have simply decided to shut up shop.

Developing new engines - it took 10 years to get the V-1710 to production. It took Continental 7 years to run a V-12 test engine! 4 years would be a tight time-scale.

Do you think the Military shared the isolationist view of the populace during the late 1930's? I don't think that is necessarily true, since when Rolls-Royce/BPC came looking for a US manufacturer to make Merlins the contract was written to guarantee a supply of Merlins to the US.

 

[wuzak]

This crap is why I haven't even read the "what if there was no Merlin" thread. The British were and are quite inventive. If the Merlin had not been developed, they would have developed ANOTHER engine.

You should see the Merlin thread Greg, because it turns out there were quite a few British options, mostly not as good as the Merlin, but options, nonetheless.

Rolls-Royce, on their own, had more liquid cooled engines in production or under development than the US did. Then you had Napiers developing their air-cooled in-lines (Rapier and Dagger) and liquid cooled in-lines (Sabre) as well as having old faithful (Lion). Bristol had a myriad of projects - both sleeve valve and poppet valve. Plus other smaller manufacturers like Armstrong-Siddeley and others that wanted to get into the market - like Fairey.

When Rolls-Royce designed the Merlin, the Kestrel and Buzzard were only 5 years old. The Kestrel had also spawned the Goshwak (evaporative cooling Kestrel), the RR/D (Diesel sleeve-valve Kestrel), the RR/P (Petrol sleeve-valve Kestrel) and was about to start development on the Peregrine.

The Buzzard wasn't a very successful engine by itself, only a 100 made, but gave birth to the R. Consideration was given to making the Griffon I, a detuned R, but that was not proceeded with in favour of the PV12/Merlin.

 

[Shortround6]

1937 is almost too late. P W had an 18 cylinder R-2600 mocked up in late 1936/very early 1937 when they decided to go for 2800 cu in. in response to the Wright R-2600. First parts ordered in March 1937. 5th production engine completed March of 1940, first time production goes OVER 2 engines a month is Dec 1940. P W used 5-6 test engines, had 3500 hours on test engines when it passed it's type test ( at 1850hp) and had spent 8 million dollars.

Starting in 1937 requires that the Army (the only real customer, both Navy and the US commercial sector are not interested) recognize/admit that the Hyper engines aren't going to be ready (let alone aren't going to work, it took the Army until 1944 to admit that one). Wright is working on the R-2600 and R-3350. Maybe they could have done it and not gotten side tracked into the R-2160 Tornado. That project sucked up about 4 years, 9 test engines/rigs and about 6.5 million between 1939 and 1943.
Most of the many liquid cooled projects in the late 30s/early 40s were too big and complicated to be in the same class ( 1300-1500lbs, 1100-1500hp) as the Merlin, Allison, DB 600 and Jumo 211 engines.
Perhaps somebody could have come up with a simple 25-33 liter V-12 without all the fancy stuff or perhaps Packard could have designed new blocks, crankcase and heads for their old V-2500 engine. Something like the Russians did when they went from the M-17 (BMW VI copy) to the M-34/35/38 type engines. But since about all you keep is the bore stroke and perhaps valve geometry ( and a few parts) I am not sure how much time/money you save.

Not every maker of marine, industrial or automotive engines can make the jump to aircraft engines ( and Continental and Lycoming were MAJOR players in the commercial industrial/automotive engine field).

The two hyper engines ( in design ?) used the separate cylinder construction used by the old Packards, the Napier Lion, the BMW VI and Russian M-17. It was a weakness that showed up all to often when the engines were pushed beyond the original design limits/specs.

 

[GregP]

Hi Wayne,

I am aware of the British options, being a LONG-TIME fan of WWII aviation. I have no favorite, but if the Merlin had not come along, one of the other options would have been used, successful or not. I think they would have worked out the bugs like they did with the Sabre. I would NOT have stick with the Sabre for so long myself.

GM would not shut up the Allison shop with a war looming. The attitudes did NOT really change. They produced war materiel for other countries for the money. Look at what Henry Ford said when asked to build the Merlin ... he said he'd build them for the USA but not for any other nation. Think he was alone in that attitude? Think again, he wasn't.

The military DID share isolationist views and was instrumental in removing the turbo from Allison use on all but the P-38 by simple order for it to happen. They didn't see any need for high-altitude equipment to defend the USA ... they were not thinking of the ETO at all. They were good about developing alternatives ... they made an Allison-powered B-17 that was faster than the radial unit, an Allison powered B-29 that was likewise faster than the radial unit, and several alternative large planes in case one failed.

I'm sorry, but I don't see any way for it to happen except for the small steps they took in rela life. You may, and you may be right, but I doubt it VERY strongly. That's OK, we have some US people in here who agee with you, but they seem to me to thinking in today's ways, not in the ways of the pre-WWII USA. I've met too many WWII vets who STILL don't like any foreign aircraft or foreign war implements. It was simply in vogue at the time. It wasn't necessarily right, but was the popular belief.

I'm sure there were a lot of British people who resented having to use US-supplied equipment (aircraft), didn't necessarily wan to fly them, and had a hard time seeing any good qualities in foreign aircraft. It's just the way it was at the time. Nothing wrong or right about it, but it was a fact that had to be dealt with.

 

[Shortround6]

Also, failing the type test is not the only way that the Allison goes missing. Allison wasn't very profitable, and GM may have simply decided to shut up shop.

Which might have happened in the spring of 1939 IF the Army had not placed the sizable contracts it did. Allison, as an engine maker ( not bearings or other engineering projects) had been loosing money for a number of years. GM had loaned the division over 1/2 million dollars and the army was 900,000 dollars behind in payments for work already done. Now maybe P W could afford to develop an engine on their own ( 8,000 engines of all types sold in 1938, more in 1939?) and maybe Wright could ( over 8,000 cyclones sold from 1926 -1938, not counting Whirlwinds and others) but what sales did Allison have from 1930 to 38?

Developing new engines - it took 10 years to get the V-1710 to production. It took Continental 7 years to run a V-12 test engine! 4 years would be a tight time-scale.

4 years is much closer to the norm but it does require that everything go right. Allison and Continental are both well outside the norm. But getting "tricky" could cost big time, How long did it take for Bristol to get sleeve valves to be a mass production item? And then there are built in delays in getting into service. The Merlin first ran in 1933 ( design started?) but wasn't suitable for production until 1936. By the time of the Munich crisis (1938) 1700 Merlins had been made but only 400 installed in aircraft. It may take 3-4 years to go from design to tested engine and first few examples. It can take another 1-2 years to get to the point of making hundreds of engines a month ( Allison, with the help of General motors AFTER GM shut/re-purposed their car plants was producing over 1200-1400 engines a month and was able to out produce ALL THREE English plants making Merlins 1943. ) In fact Ford was licensed to make R-2800s in Aug of 1940. in Nov 1941 they turn out 99 engines, Buick was licensed in Oct 1940 to Build R-1830s. They produce NONE until March of 1942 when they put out 440 engines. Studebaker was licensed to produce R-2600s in Nov of 1940 but was switched to R-1820s in June of 1941. They trickle out a few engines in Feb/March of 1942, 35 in April and 168 in May and just keep multiplying.
Basically, even with a full set of plans for an existing, tested, approved engine you are looking at about 1 1/2 years before you can get them in any real numbers. Ceremonial role outs and 1-5 engines a month don't cut it in war time. Add another 6-9 months if you are looking for 1000 engines a month.

 

[Shortround6]

GM would not shut up the Allison shop with a war looming.

Allison had to "forgive" the Army's 900,000 dollar dept in return for permission to export Allison engines. There is only so long any company can keep going without income even with a war looming.

The military DID share isolationist views and was instrumental in removing the turbo from Allison use on all but the P-38 by simple order for it to happen. They didn't see any need for high-altitude equipment to defend the USA ... they were not thinking of the ETO at all.

Not this old myth again. The Army actually had a pretty good idea how close the turbo was to actual service use. About 2 years from the summer of 1939. They figured that NON-TURBO p-40s/P-39s could be ready in one year. Not knowing WHEN the war would start they figured that non-turbo P-40s/P-39s in squadron service in numbers beat the heck out of turbo-models still undergoing development testing. Turns out the army was wrong. The Turbo planes were still having problems in the Spring/summer of 1942. Longer than 2 years.

 

[GregP]

It isn't a myth at all ... but I won't argue much about it.

The P-38 didn't have turbo problems ... it had intake manifold issues, European fuel different from American fuel issues, and poor pilot training. When these were addressed 9 months later, the P-38 was a solid aircraft with very few troubles other than a really piss-poor cockpit heater. They cured that one with an electric heater. By that time the P-51 was in the theater and there was no poiin t having a supply chain for two fighters for the same job ... so the P-38 got transferred to the MTO / PTO / CBI and did well.

You might remember it was the mount of our top two aces.

 

[wuzak]

It isn't a myth at all ... but I won't argue much about it.

The P-38 didn't have turbo problems ... it had intake manifold issues, European fuel different from American fuel issues, and poor pilot training. When these were addressed 9 months later, the P-38 was a solid aircraft with very few troubles other than a really piss-poor cockpit heater. They cured that one with an electric heater. By that time the P-51 was in the theater and there was no poiin t having a supply chain for two fighters for the same job ... so the P-38 got transferred to the MTO / PTO / CBI and did well.

You might remember it was the mount of our top two aces.

You are talking of a few years after the time of which Shortround speaks.

The XFM-1 had problems with turbos.
The YFM-1 had problems with turbos.
The XP-37 had problems with turbos.
The YP-37 had problems with turbos.
The XP-39 had problems with turbos.

The "European fuel" issue happened in 1943/44, IIRC.

And P-38s did have problems with turbos - requiring a redesign of the wastegate control, as it would sometimes freeze shut.

 

[GregP]

Yeah, they had issues with turbos, but the issues weren't necessarily the turbos, It nwas the system, which isn't the same thing.

The Airacuda as a joke and I ignore it as non-typical. There is no set of circumstances that would render it viable.

The X/YP-37 was an experimental plane designed to investigate the use of turbochargers. If it had issues, that is what it was FOR. To investigate them. No surprise.

The XP-39 was well on its way to having any issues resolved when the turbo was removed by the war materiel board. It might have been high-drag and probably was, but WOULD have imbued the P-39 with altitude capability that it didn't otherwise have.

If that is not so, then why was the turbo installation in the P-38 any better? ... But it WAS. FDew issues with the tirbo ... So they were on the right track and could have done it if the USAAF had wanted to do so. They didn't.

Too isolationist and not-caring of events around the world to take notice. Their "high-altitude" plane was the P-38. They COULD have had a high-altitude P-39 and P-40, but didn't.

Silly, really, but simple. Bean counters made the decisions ... with pre-war attitudes in full bloom.

 

[wuzak]

Yeah, they had issues with turbos, but the issues weren't necessarily the turbos, It nwas the system, which isn't the same thing.

Sometimes it was the installation, other times it was the turbo.

The Airacuda as a joke and I ignore it as non-typical. There is no set of circumstances that would render it viable.

It still had problems with the turbos. The turbo that the Airacuda used was of the older style - with the compressor intake between the turbine and compressor.

The X/YP-37 was an experimental plane designed to investigate the use of turbochargers. If it had issues, that is what it was FOR. To investigate them. No surprise.

The X/YP-37s were not turbo test beds. They were used to evaluate the V-1710 in a persuit type airplane.

The XP-37 had the older type turbo, the YP-37s had the newer type, which would become the B-series turbo.

The XP-39 was well on its way to having any issues resolved when the turbo was removed by the war materiel board. It might have been high-drag and probably was, but WOULD have imbued the P-39 with altitude capability that it didn't otherwise have.

The issues were resolved by NACA by dumping the turbo and tidying the aerodynamics.

If that is not so, then why was the turbo installation in the P-38 any better? ... But it WAS.

The P-38 was a twin engine airplane, so the turbos didn't cause problems with space in the fuselage - as they did for the X/YP-37 and XP-39.

Few issues with the turbo ... So they were on the right track and could have done it if the USAAF had wanted to do so. They didn't.

Still had problems with the turbos.

They COULD have had a high-altitude P-39 and P-40, but didn't.

The P-40 was never intended to have a turbo. Basically the X/YP-37 showed them it was impractical to have a turbo at that time, so the P-40 was designed without one.

 

[GregP]

From Don Berlin's son visiting the Planes of Fame, the P-40 WAS intended to have a turbo from the outset. It just never got one in production.

The P-37 WAS an experimental plane with one intent to investigate the turbocharger. It wasn't EVER going to be a service interceptor with the rearward cockpit position.

The issues with the P-39 were NEVER resolved by the NACA ... they did their best to clean it up when the turbo was deleted, and did a decent if not spectacular job. The turbo could have worked at LEAST to get the Airacobra to altitude if not too much faster. I think it WOULD have been solved if they had persisted. They didn't.

Don't care in the least about the Airacuda ... it was a stupid thing to start with. Somebody was a hairbrain. It happens every once in awhile ... I DO have a nice CAD drawing I did of it, but am NOT a fan. I did it for a friend who overhauls Allisons ... Joe Yancey. The Airacuda reminds me of an old 1950's sci fi prop that was used in a stupid movie. Doesn't have to live in the real world but must convey somthing different from the norm. That ... it does.

 

[Shortround6]

P-43s had problems with the turbos, early B-17s had problems with the turbos. Actually this wrong, the turbo itself may have been OK (?), the turbo controller was the main problem. The early controller/s (supplied by the army, NOT the engine maker or General Electric) measured the pressure in the exhaust system and tried to keep it at a constant value by adjusting the bypass/waste gate, this was supposed to keep the intake pressure at a constant value/pressure. Due to the moisture in the exhaust it did freeze up a lot. The later controls switched to sensing the intake pressure and adjusting the waste gate ignoring exhaust pressure.
Part of the P-39s problem (and a potential problem for the P-40) was the inter-cooler. Without an inter cooler the turbo is severely limited in what it can actually accomplish. P-38 used the leading edge of the wing on the early ones. This intercooler design was not particularly space efficient but note that the space was of a size to house 55 gallons of fuel in self sealing tanks on later models. Later (or other types) intercoolers didn't use as much volume. The drag of the inter cooler and turbo cost the P-39 around 30-40 mph at altitudes below 15,000ft.

I would like somebody to tell me where the turbo and inter-cooler were supposed to go on the P-40? What 10-12cu ft of space is there in an appropriate relation to the CG for a turbo and inter-cooler? The Hawk 75 prototype with a two stage supercharger and inter-cooler used a large pod/duct under the cockpit-fuselage. The Later P&W test mule with two stage supercharger may have used the space in the fuselage used by the cowl gun ammo storage, or perhaps there was more room behind the radial than there would be behind the V-12?

For those who think the P-39 could have been fixed please note that Bell themselves didn't really try, aside from a couple of add-on turbo installations (both turbo and intercooler mounted external to the original fuselage contours. Instead they went to the P-39E (P-63) with a two foot longer fuselage and new wing. Granted in part to house the Armies favorite engine ( the Continental I- 1430) which was about 20in longer than the Allison but the extra room came in handy for remote 2nd stages.

 

[wuzak]

Not sure where the turbo would go on a P-40. Not that I believe the P-40 was ever going to get one.

But the clues may be in the XP-60 and XP-60A.

Here is the XP-60 with the V-1650-1:

Quite slender and sleek.

And here is the XP-60A, with V-1710 and GE B-series turbosupercharger

Quite corpulent!

Wonder if the turbo is on the lower side of the fuselage, between the wings and just behind the radiator outlets.

 

[GregP]

Not sure where it went on the P-40 either but, since it didn't have one in production, the question is moot.

Acording to Nr. Berlin's son, Don was allowed to build ONE turbo P-40 and I have been chasing a pic or description of it for years to no avail as yet. I hear rumors about it, and rumors about good performance at altitude, but can't confirm any of them. So they are sort of things to look into as I can find out anything about them.

At this time I would not claim that it was so, only that I have heard it said. You never know. Sometimes these things are true and sometimes they just can't be confirmed by a reliable source. Those are dying off these days and this one may simply have no evidence either way, which tends to lend doubt to the claim altogether, but that also may not be right. I can't say for sure.

Early turbochargers (or turbosuperchargers, as they were called back then) were problematic. Today they are reliable and rarely malfunction. The early issues do NOT mean that all were problematic or insoluable ... the P-38 DID perform well once the issues were ironed out. The P-39 may well have been able to develp along the same lines, though I doubt it. I would like to have seen a turbo P-63 as it certainly had the room for a good system and is a very good candidate.

 

[wuzak]

Greg, I believe the P-60A is the closest thing to a turbo P-40. If you discount the X/YP-37s.

The P-60A had the V-1710 and GE turbo. The P-60B was to have the V-1710 and Wright turbo. The P-60C was supposed to get the IV-2220, but ended up with the R-2800. The P-60D was the XP-60 re-engined with the V-1650-3 (the XP-60 had the V-1650-1). And the P-60E had the R-2800.

The XP-60A made its initial ground taxiing tests in late October of 1942. However, during one of these tests, a minor fire occurred in the engine due to the lack of cooling air in the shrouds surrounding the exhaust manifold. The turbosupercharger and long exhaust manifold were therefore removed from the aircraft, and short exhaust stacks were substituted. The XP-60A (42-79423) flew for the first time in this form on November 11, 1942. Empty weight was 7806 pounds, gross weight was 9616 pounds, and maximum takeoff weight was 10,160 pounds. Dimensions were wingspan 41 feet 3 3/4 inches, length 33 feet 7 1/2 inches, height 12 feet 4 inches, and wing area 275 square feet. Estimated maximum speed (never achieved in tests) was 420 mph at 29,000 feet and 324 mph at sea level. It was estimated that an altitude of 15,000 feet could be attained in 6.5 minutes. Service ceiling was 35,200 feet. The maximum speed (especially at low altitudes) and the initial climb rate were rather disappointing. The XP-60A aircraft was soon dismantled and some of its parts were used in the later XP-60C and XP-60E.

Curtiss P-60

The XP-60 had a maximum speed of 387mph. It was basically a P-40 with new "laminar flow" wings and a V-1650-1. No idea how the XP-60D went.

There could be some confusion between XP-60 and P-40, though the turbo XP-60s (A B) didn't share as much with the P-40 as the XP-60 did.

 

[GregP]

Yes, I am aware of the P-60 series. The rumors are of a turbocharged P-40, not the XP-60 / P-60. Again, I cannot say and have no conviction about it one way or the other myself. I'd like to find out for sure, though. Who knows? Maybe sometime.

Meanwhile, back to topic.

 

[Shortround6]

I don't know if they built one with a turbo charger or not but the lack of any pictures/drawings/test reports sure doesn't look good.

From Joe Baugher's web site. "The designation P-40J was given to a projected version of the P-40E which was to have a turbosupercharged engine. This study was abandoned in May 1942 without anything ever being built".

Considering they can find out the serial numbers of the planes used for experimental radiators and have pictures of them the lack of information on the "turbo P-40" is mighty strange if it existed. Not 100% proof it didn't but.........

The letter designation is also strange IF the P-40 was designed for a turbo. The 8th version built gets one?

At best you have "A P-40 was designed to have a turbo charger" which is quite different than "the P-40 was designed to have a turbo charger."

 

[wuzak]

We do know that the P-40s origins were for a non-turbo V-1710 P-36 version.

Don Berlin, Chief Designer at Curtiss for the P-36 and P-37 aircraft, was frustrated by the continuing problems with the turbosupercharged XP-37 [models 75I and 80], and the lack of potential for the P-36. Given the urgency of the upcoming 1938 Persuit Competition, he obtained from Allison an estimate of cost and performance of an "altitude" rated V-1710 for use in a P-36 derivative.

Using the information and the promise of 1050 bhp, on March 3 1938 Curtiss submitted to the Materiel Division a proposal for a P-36 airframe mated to this engine. It stated in part, "Wind tunnel tests indicate that (a P-36) with the Allison V-1710 (altitude rated) engine, a high sped of 350mph at 15,000 feet is possible. This is based on a modified V-1710 having a gear-driven supercharger giving 1000 bhp at 2,600 rpm at 15,000 feet. It is estimated that this engine will develop 1050 bhp at 2950 rpm at 15,000 feet with carburettor ram air..." Wright Field immediately approved Allison to proceed with the design change to the engine, and for Curtiss to proceed with the installation of the engine in the number ten P-36A airframe. Thus the P-40 series was born in teh form of Curtiss Design 75P, Air Corps designation XP-40 (AC-38-010).

From Vees for Victory.