VI: no Allison V-1710

For some conceivable reason (no support by US military, Allison is not bought by a company that has money, USAAC goes even more firmly against a V12 that does not fit the 'hi-per' mantra, etc.), the V-1710 does not came about. The hi-per engines also don't materialize, as it was historically the case. How might the USAAC/AAF fighters look like after the P-35/36/43 generation is designed, especially in 1940-1942?

tomo pauk said:

For some conceivable reason (no support by US military, Allison is not bought by a company that has money, USAAC goes even more firmly against a V12 that does not fit the 'hi-per' mantra, etc.), the V-1710 does not came about. The hi-per engines also don't materialize, as it was historically the case. How might the USAAC/AAF fighters look like after the P-35/36/43 generation is designed, especially in 1940-1942?

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Packard does a dodgy deal with Rolls-Royce to licence build the Merlin using a shady Bahamas based holding company and pretends that the engine they build is all American. Meanwhile General Motors, Ford do similar deals with Daimler-Benz and Junkers.

Kevin J said:

Packard does a dodgy deal with Rolls-Royce to licence build the Merlin using a shady Bahamas based holding company and pretends that the engine they build is all American. Meanwhile General Motors, Ford do similar deals with Daimler-Benz and Junkers.

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Alternately, the XP-41 & XP-42 go into production instead of the Warhawk and Airacobra. The production versions use the R-2600. The Lightning is never built, the XP-50 goes into production instead.

Pratt&Whitney Aircraft and Curtiss-Wright pick up more government contracts and the USAAC looks, with envy, at the sexy V-12s from Europe until their well-designed round-engine fighters meet them in combat and consistently perform as well or better.

Well, one thing jumps out. There is no P-51 Mustang and North American Aviation sticks to building bombers. It takes longer to develop a long range fighter escort to make the strategic bombing campaign in the ETO effective, possibly delaying the Normandy landings by a year.

OTOH, a twin PW powered P-38 Lighting with turbo-supercharging would be an interesting thing....

Kevin J said:

Packard does a dodgy deal with Rolls-Royce to licence build the Merlin using a shady Bahamas based holding company and pretends that the engine they build is all American. Meanwhile General Motors, Ford do similar deals with Daimler-Benz and Junkers.

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No one would do any of that without a contract.

The US was not without available engines and if Allison never developed the V-1710, I'm sure otjers would have taken it's place.

Packard had it's V-1650 (the Liberty L-12 not the Merlin V-1650) and 1A-2500, Chrysler had it's V-2220, Ranger had it's V-770 plus others under development, Continental had it's I-1430, Ford had it's GAA and it's variants: GAC, GAF and GAN.

So there were plenty of options out there...

GrauGeist said:

The US was not without available engines and if Allison never developed the V-1710, I'm sure otjers would have taken it's place.

Packard had it's V-1650 (the Liberty L-12 not the Merlin V-1650) and 1A-2500, Chrysler had it's V-2220, Ranger had it's V-770 plus others under development, Continental had it's I-1430, Ford had it's GAA and it's variants: GAC, GAF and GAN.

So there were plenty of options out there...

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Agreed, it's a very unlikely scenario.

swampyankee said:

No one would do any of that without a contract.

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I didn't mention no contracts, just done out of the neutral and anti-war public eye.

GrauGeist said:

The US was not without available engines and if Allison never developed the V-1710, I'm sure otjers would have taken it's place.

Packard had it's V-1650 (the Liberty L-12 not the Merlin V-1650) and 1A-2500, Chrysler had it's V-2220, Ranger had it's V-770 plus others under development, Continental had it's I-1430, Ford had it's GAA and it's variants: GAC, GAF and GAN.

So there were plenty of options out there...

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Either of those had no firm answer to the question of emulating or bettering V-1710-33 (roughly 1000+ HP at 13000+ ft), "especially in 1940-1942". The Chrysler V-2200 certainly, ditto for V-770. Liberty for ww2 is non starter, the beefd-up 1A-2500 might be interesting?
Ford have had a 2-cylinder test mule in works in mid 1940 for their V-1650. The Continental I-1430 never powered an aircraft before 1943?

USAAC/AAF's best bet should probably be carrying on with radial engines on fighters, too? A 2-engined fighter with turbocharged R-1830 instead of P-38? A P-36 with a 2-stage R-1830 instead of P-40? The R-2180A gets better funding?

tomo pauk said:

Either of those had no firm answer to the question of emulating or bettering V-1710-33 (roughly 1000+ HP at 13000+ ft), "especially in 1940-1942". The Chrysler V-2200 certainly, ditto for V-770. Liberty for ww2 is non starter, the beefd-up 1A-2500 might be interesting?
Ford have had a 2-cylinder test mule in works in mid 1940 for their V-1650. The Continental I-1430 never powered an aircraft before 1943?

USAAC/AAF's best bet should probably be carrying on with radial engines on fighters, too? A 2-engined fighter with turbocharged R-1830 instead of P-38? A P-36 with a 2-stage R-1830 instead of P-40? The R-2180A gets better funding?

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Somewhere, I've seen reference to a navy P-36 with R-2600 with a performance similar to Seafire Ib / IIc. Service intro I presume, 1941/42? That would be good as an interim type before Hellcats and Corsairs arrive.

The L-12 series was the genesis of the IA-2500 (circa 1924: 800hp), 2A-2500 (circa 1925: 800hp), 3A-2500 (circa 1926: 800hp), 4A-2500 (circa 1927: 900hp supercharged), 5A-2500 (circa 1930: 1,500hp) and this does not include the high output "M" marine variants. You'll note that these engines were well before WWII and would have been available for prioritized development if Allison had not developed their 1710 (or even their 1450).

The IA-2500 even had an inverted "V" variant, too.

GrauGeist said:

The L-12 series was the genesis of the IA-2500 (circa 1924: 800hp), 2A-2500 (circa 1925: 800hp), 3A-2500 (circa 1926: 800hp), 4A-2500 (circa 1927: 900hp supercharged), 5A-2500 (circa 1930: 1,500hp) and this does not include the high output "M" marine variants. You'll note that these engines were well before WWII and would have been available for prioritized development if Allison had not developed their 1710 (or even their 1450).

The IA-2500 even had an inverted "V" variant, too.

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Yes, indeed, those Packard engines might be worthy pursuing.

GrauGeist said:

Packard had it's V-1650 (the Liberty L-12 not the Merlin V-1650)

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The Liberty was a non contender. It used a 7 in stroke (Griffon used a 6.6in stroke) which was going to limit RPM even if the crankshaft and crankcase would stand up to the strain and at a weight of 845lbs (dry) that is highly doubtful.

Packard themselves had a built a 1500 cu in V-12 starting in 1924. It apparently had reliability problems? but around 250 were made? Or couldn't compete price wise with war surplus Liberty engines ( US was still selling them, new in crates in the late 20s).

and 1A-2500

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The 1A-2500 is from 1924, they eventually got to a 5A model. This was obviously a large engine and the one the torpedo boat engines were based off of.
However it is an engine based on mid 1920s metallurgy and mid 1920s knowledge of vibration. It was also not supercharged meaning that it's strength at higher powers is very questionable without extensive redesign (new engine), Weight was only 1385lbs for such a large engine and that does include the reduction gear on the 3A model.

Chrysler had it's V-2220

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not for a number of years, like 1944(?) for flyable example.

Ranger had it's V-770 plus others under development

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Way too small for any really useful airplane, even bigger developments. The highly supercharged V-77o intended for the XP-77 neve showed up and even the post war version never came close to the promised performance of 1941/42.

Continental had it's I-1430,

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and we know how that turned out despite being the Army AIr Corps fair haired boy.

Ford had it's GAA and it's variants: GAC, GAF and GAN.

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Too late, Ford would have had to pull a near miracle to get a two cylinder test rig going in the summer of 1940 as they didn't even start design work until the summer of 1940 after seeing the Merlin drawings and examining an sample engine.

People tend to forget how many Allisons were made in 1940 and 1941 and replacing them without build additional factories in 1939-40 is going to be very difficult.
remember that the orders for the P-40 and Allison engines were placed in April of 1939, P & W and Wright were already busy expanding their factories several time over. The Fall of 1940 saw Buick, Chevrolet, Ford, Studebaker and others (Packard was already in) being brought in for vastly more capacity but the those engines won't being to show up until spring of 1942 and in real quantities until the summer/fall of 1942.

We can throw the Lycoming O-1230 into the mix but it doesn't change things much even if two of the "welded together" powered the Vultee XP-54.

Shortround6 said:

Too late, Ford would have had to pull a near miracle to get a two cylinder test rig going in the summer of 1940 as they didn't even start design work until the summer of 1940 after seeing the Merlin drawings and examining an sample engine.

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That detail is often overlooked.

If the possibility of a Merlin contract hadn't been around, would Ford have bothered?

Would the Pratt & Whitney X-1800 have received more attention?

wuzak said:

Would the Pratt & Whitney X-1800 have received more attention?

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Possibly, but then would Pratt & Whitney have been able to put as much effort into the R-2800 B, The R-2800 C and the R-4360 and the R-2000?

GrauGeist said:

The US was not without available engines and if Allison never developed the V-1710, I'm sure otjers would have taken it's place.

Packard had it's V-1650 (the Liberty L-12 not the Merlin V-1650) and 1A-2500, Chrysler had it's V-2220, Ranger had it's V-770 plus others under development, Continental had it's I-1430, Ford had it's GAA and it's variants: GAC, GAF and GAN.

So there were plenty of options out there...

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Sure. A lot of them were round and air-cooled (although round and liquid-cooled was certainly practical).

Granted, it's probably more difficult to design a low-drag cooling system for a radial (it's even harder for an air-cooled inline) than for a liquid-cooled engine, it is possible. Certainly, there's little reason for a radial installation to have more cooling drag than the V-12 installation in the FW190-Ds. Radiators are likely going to have similar or greater pressure drops than the cooling fins on a radial; it's just that one can move the radiator and its inlets to where ever is most convenient. Despite this, some liquid-cooled engines had horrendous cooling drag. I remember reading that the installation in the Ju87 was particularly bad, although I also suspect given all the other drag-inducing excrescences, nobody cared.

The X-1800 seem to fall in R-2800 weight and power bracket?
P&W might continue with R-2180A - latest mark before it was put on the ice was to make 1500 HP. Japanese bought the 1400 HP version, for 91 oct fuel.

The problem is a what altitude?
Most R-2180s were rated at 1400hp for take-off (on US 100 octane) at 2500rpm. Max continuous was more variable but was often 1150hp at 6-7000ft. There was a two stage engine proposed that was supposed to give 1150hp at 17,500ft max continuous and weighed 1810lbs. The engine in the early Wildcats could give 1000hp at 19,000ft for 1550-1575lbs. the R-2180 was not a small engine, it was about 1 in (25mm?) smaller in diameter than than an R-2800.
The R-2180 was only going to provide an incremental improvement and would need to be replaced very quickly. The more time spent on it just delays the R-2800.

Only about 30 engines were built so there was no large investment in production tooling.