WI: The Allison V3420 was a success?

Following a post here...

The V3420 was mooted before WW2, but was ultimately suppressed by the need for more V1710s. So WI Allison had given it a bit more attention & gotten approved for, frex, the B-29, instead of the R3350? Or for the A-36, instead of the Merlin? Or P-39 or P-63? How different would the war have been? Would it make any real difference?

One thought: without the R3350s teething problems, the B-29 might have entered service a bit sooner, putting pressure on the Bomb program to deliver a working core sooner...

More V3420s might have impacted civil aviation postwar, with fewer (no?) R3350-powered Connies & such, & no problems with turbocompound turbine failures. (Can that be traced to the cause of any fatal wrecks?)
 

Archibald

Banned
You are welcome. You mention the B-29 / B-39, and there was a great might-have-been that used the Allison V-3420: the Fisher P-75 Eagle long range escort fighter (that was made unuseful by the P-51 Mustang). 2500 of them were planned but never build.
https://en.wikipedia.org/wiki/Fisher_P-75_Eagle
I don't think the V-3420 could be shoehorned into V-1710 -powered aircrafts since it was twice as big - i mean not single engine fighters. So forget P-39 / P-63 and Mustangs.

Multi-engine types (heavy fighters and bombers) have more room for growth: the P-38 could have grown into either P-49 or P-58.

I think you nailed it right about the B-29. Early R-3350s were piece of junk, really. Somewhat as bad as He-177 engine kludges when you think about it.
 
I was a bit dubious about the A-36 or P-40. The P-39, less so, since the V1710 sat on/near Cg. (Fuselage would need widening, true.) The P-63 could have been designed around the V3420, so...

I do like your XB-42 idea.:cool: I'm a fan, too. (It also suggests the possibility of a successful DC-8.:cool:)

I think you're right about the P-49 or P-58; TTL, the P-49 might actually see service. (In keeping with this, can I hype my own thread & suggest V3420s in the *B-13/B-38?;))

IMO, the P-75 has too many issues to ever see service...
 
I think you nailed it right about the B-29. Early R-3350s were piece of junk, really. Somewhat as bad as He-177 engine kludges when you think about it.

No, the early engines, like the -10 were reliable as most new engines, but got worse with the next series of improvements that Wright tried, then hooking up dual turbos did not help.
But the first series ran fine in stuff like the XP4Y Corregidor flying boat
 
No, the early engines, like the -10 were reliable as most new engines, but got worse with the next series of improvements that Wright tried, then hooking up dual turbos did not help.
But the first series ran fine in stuff like the XP4Y Corregidor flying boat
I suspect the R3350 gets a bad rap in airline service because the airlines were pushing them too hard, to achieve unrealistic schedules.

Given the R3350 was virtually all-new, & the V3420 nearly all-V1710, IMO the development of the V3420 should go much more smoothly, & quickly, given equal priority--& when the V3420 goes a lot better, there'd be a good chance the R3350 would be dropped entirely.

Something like turbocompounding or two-stage turbocharging on the V3420 postwar (or late war) would be good for the airlines. (Might appear on late B-29s or early *B-50s, if it doesn't on the *P-63 Airamamba.:p)

A couple of thoughts: would the V3420 be thirstier than the V1710, & so require greater fuel capacity in a fighter? (So tiptanks.:cool: Or leading-edge tanks, like the P-38.) Would it have more hp enough to add guns in the nose, or be enough heavier to "demand" more nose guns, in the *P-63, to keep the Cg in place?
 
Stick it on the P-47.
Or a tank. It's nicely low in height for AFV applications.

NASM-A19660386000-NASM2014-05088.jpg


AllisonV-3420.jpg


Now just keep wrapping it in pistons and you'll get a massive liquid-cooled radial like the https://en.wikipedia.org/wiki/Lycoming_XR-7755

https://en.wikipedia.org/wiki/Category:Water-cooled_radial_engines
 
in red if the Kingcobra, the black is Fisher P-75.
That's with the P-63 designed around the (narrower) V1710; the mooted Airamamba would be designed around the V3420, just as the P-75 was. (Overcoming the other airframe limitations is a bigger problem...but if it's a clean sheet of paper, maybe those can be overcome, too.)
 
Please, people, let's not allow Bell to develope any aircraft after the P-39. They can switch to the helicopter business though.
 
Please, people, let's not allow Bell to develope any aircraft after the P-39. They can switch to the helicopter business though.
Hmm...

I'd like to give them a chance to get it right.:openedeyewink: Besides, I like the mid-engine idea, & I'd like to see it succeed. (Okay, the P-39 wasn't exactly a failure, but a top-rank fighter it wasn't.) The *P-63 (would it be renumbered TTL?) Airaconda (that sounds more like the Bell "naming system") might be it.
 
Thunderbugger.png


I did manage to find a nice fit for the double-Allison in the Thunderbugger. I asked a high-scoring allied ace what he thought of the Kobry and he said "duh".
 

Archibald

Banned
The P-39 wasn't a very good combat aircraft according to Wallies standard but for Soviets it was different. Just the fact it had an onboard radio had the Soviet use them to set traps on the Luftwaffe. Also the heavy armement, far heavier than any Yak (Yaks were just like Italian or Japanese fighters, that is "we give you two machine guns and nothing more, fight with that, or die.") a single 20 mm or 37 mm gun plus four machine guns, that was pretty heavy by Soviet standards.
 
Tell that to the Soviets, it was an Ace maker for them.
I don't count the Red AF as top-rank, either. Compare to the Spit or P-51 or 109, or even the P-40 or Hurricane. The P-39 wasn't a disaster, but it should've been an A-21 or something. The *P-63, with more hp & laminar wing to begin with, might have at least approached P-51 performance.
 
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