wuzak
Captain
If the engine bay of the P-39 and P-63 were the same, would I be right in assuming that the auxiliary supercharger in the P-63 was not actually in the engine bay?
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Lets not forget the the P-39E/P-76If the engine bay of the P-39 and P-63 were the same, would I be right in assuming that the auxiliary supercharger in the P-63 was not actually in the engine bay?
Why are we arguing about putting in a different engine in the P-39 when Bell actually designed a successor aircraft to the P-39 to hold that very engine?
It's like saying the B-17 would have been a super bomber if Boeing had only put R-3350s in it.
Yeah, but when Boeing wanted a better bomber they built the B-29, but again, if the P-39 was living up to expectations, why build the P-63? Why not just put the new engine in the P-39, like other Greg hinted at?Well, they DID re-engine a B-17. Here's one with four Allisons.
Not the point, Greg, when Boeing wanted a better bomber they built the B-29, but again, if the P-39 was living up to expectations, why build the P-63? Why not just put the new engine in the P-39?
Could have been that while with a very large shoehorn, a set of tin snips and a rather cavalier attitude about weights/balance and CG you could get the engine into the engine bay. However some bright young spark figured out that since the P-39 was skating on very thin ice in regards to cooling with the existing radiator and oil coolers fitting and engine that generated several hundred more HP in the cylinders and flew higher (thinner air doesn't cool as well) they were headed for disaster without larger radiator/s and oil cooler/s?
1125hp to prop plus about 100hp for internal friction plus around 250hp to drive the supercharger equals around 1475hp in cylinders for a cooling load at 15,000ft for the single stage engine.
1125hp to the prop plus about 100hp for internal friction plus around 125hp to drive the engine supercharger plus around 300hp to drive the auxiliary supercharger equals around 1650hp in cylinders, now trying to cool that heat load (about 12% greater) at 22,000ft where the air is only 79% as dense (Lbs per cubic ft) is not going to end well.
Figures are a little rough but do point out the problem.
Does it say if the tank was brass or aluminum by any chance?BTW the coolant expansion tank in the P-63 held 1 1/2 gallons per the flight manual, which also says that the P-39 tank held 3 gallons.
Just timing. The new engine was in production from April 1943 but the new P-63 airframe wasn't ready until that October. Seven months wasted in mid 1943 when those engines could have been installed in P-39s.Why are we arguing about putting in a different engine in the P-39 when Bell actually designed a successor aircraft to the P-39 to hold that very engine?
It's like saying the B-17 would have been a super bomber if Boeing had only put R-3350s in it.
Just timing. The new engine was in production from April 1943 but the new P-63 airframe wasn't ready until that October. Seven months wasted in mid 1943 when those engines could have been installed in P-39s.
Just timing. The new engine was in production from April 1943 but the new P-63 airframe wasn't ready until that October. Seven months wasted in mid 1943 when those engines could have been installed in P-39s.
Seven months is barely enough time to install and flight test a new engine, then you have to change the production lines. Seven months won't get a single souped-up P-39s to squadrons.
Just timing. The new engine was in production from April 1943 but the new P-63 airframe wasn't ready until that October. Seven months wasted in mid 1943 when those engines could have been installed in P-39s.
This one looked like 6 50's with only two firing on the left side like #3 was jammed.This is one of those ones shown flying in the New Zealand air show
Standard late 1942 P-39N compared with a contemporary FW190A-6. Pretty competitive. Plus P-39 was more maneuverable and had longer endurance.What I'm getting from all this discussion is that in order for a Bell aircraft (be it P-39 or P-63) to be competitive with contemporary Luftwaffe types is that the stars need to perfectly align.
First Allison has to be producing the 2 stage engine in quantity no later than mid 1940 (approximately 3 years early?).
Then Bell has to make sure the airframe design is able to fit the engine (from 3 years in the future) with the aforementioned 2 stage supercharger (with sufficient cooling, not to mention W&B)
and the government must be on board with channeling the 2 stage engine to the Airacobra program.
Is that about right or am I missing something? While we're at it, maybe that beer truck runs over a certain procurement officer (drgondog's assessment from an earlier thread) and the Mustang gets the 2 speed 2 stage supercharged Merlin a year early and P-51's are available for LR escort in Mid 1943.
Really only three months to get a new engine into a fighter per Vees for Victory. No production stoppage when the P-39 changed from the -35 to the -63 to the -83 and the -85. The -93 was a bit more complicated but doable in my opinion.Have to disagree here. Seven months is barely enough time to install and flight test a new engine, then you have to change the production lines. Seven months won't get a single souped-up P-39 to a squadron.
Given that Bell already had the P-63 in the works, it makes no sense to syphon off scarce design and engineering resources to up-engine the P-39. Bell clearly felt that the P-39 was at the end of it's development potential. No point investing in a dead-end.
Really only three months to get a new engine into a fighter per Vees for Victory. No production stoppage when the P-39 changed from the -35 to the -63 to the -83 and the -85. The -93 was a bit more complicated but doable in my opinion.