On Oct 6, 12:36 pm, Bob Matthews wrote:
Daryl Hunt wrote:
"The Amaurotean Capitalist" wrote in
messagenews:bkg7g3952ul9la8qpgnmaathtktjd6jp3u@4ax .com...
On Wed, 03 Oct 2007 08:31:19 -0700, "Scott M. Kozel"
wrote:

The critical improvement to the Mustang was the fitting of the RR
Merlin engine
which was an RAF idea.
Given that over 15,000 P-51s were built by North American Aviation in
the U.S. and paid for by the U.S. government, it was predominently a
U.S. aircraft. Like you said, the later models did use the Merlin
engine.
The critical point is that the P-51 would not have been sustained in
production without the RAF championing the type on the basis of the
Merlin installation in mid-1942. It was never a part of USAAF
procurement until October 1942, and it took substantive British
efforts to get the USAAF to accept it as a major production type.

So it's certainly a US aircraft, but it wouldn't have existed without
substantial British input both in technological terms, and production
advocacy from the initial Allison-engined British purchase contracts
to the Merlin conversion.

Gavin Bailey

Keeping it in the whatif department. Whatif they had installed decent
Turbos and Supers on the Allisons. What would that have done for even the
P-40. Afterall, later productions on the P-38 and the P-47 would have had
equal or more range and speed of the P-51C and the P-40 would have had near
identical performance and speed.

Really? Seems like the P40's wing and overall aerodynamics made it less
efficient therefore slower with the same power.

US doctrine required a fighter with a large fuel capacity for long
range. This
produced a rather large aircraft with a lower power to weight ratio
than the
little european fighters and therefore a lower climb rate and
acceleration.

Having said that the aircaft was very pleasant to fly and a good
turning circle
and excellent pre stall buffet warning. If given a single stage
Merlin it matched
the Spitifire Mk.V in speed. It never got the Two stage Merlin 66 or
70 (packard 266)
but with it probably would have been the same speed as a Mk.IX spit
but with
longer range, less climb rate and less dive speed.

The Mustang had the laminar flow wing and only it could crack the
440mph barrier
with the Merlin. The P-51 was also a heavy aircraft but the laminar
flow wing made
up for it. The P-51's laminar flow wings were laminar becuase of
dimples, bugs and
scratches but one property of the laminar flow wings design is a very
gradual
pressure profile that prevents 'compression' of the air and other
transonic effects
that cause drag and also stiffen airlerons.

It probably just didn't make sense to waste effort upgrading the P-40
with a two
stage Merlin when the Mustang could already do so much better.

This is my whole point. If you waste resource building aircraft that
prevent
you from building ones that do work better.

A few turbo-supercharged Allisons that were made, were allocated to
P-38s, making the high-altitude performance of that plane its best
feature. All 14,000 P-40s got gear-driven superchargers, and as a
result, were never first-class fighter planes. Donaldson R. Berlin,
the P-40's designer, has said that P-40s experimentally equipped
with turbo-superchargers outperformed Spitfires and Messerschmitts
and that if it had been given the engine it was designed for, the
P-40 would have been the greatest fighter of its era. This may be to
some extent the bias of a proud parent, but there is no doubt that the
deletion of the turbo-supercharger ruined the P-39 and in one case
ruined the british turboless P-38s

Had Allison's engineers been able to put the effort into gear-driven
superchargers that Pratt and Whitney and Rolls-Royce did, it might
have been a different story. As it was, there can be little doubt that
the V-1710 had more potential than was actually exploited.

I think the refractory metals were required for the bombers which
needed them more.