Originally posted by Puck
How about non-random? A P-38 with Merlin engines. Kelly Johnson had the drawings made for the conversion, and they were available early on. Wright Patterson specifically FORBADE anyone to put a Merlin in a P38[1], but I'm surprised the British didn't try it. That's what made the Mustang flyable; imagine what it would have done for the P38...
[1] While this seems arbitrary and capricious, consider for a moment that they could engine two P-51s for every P-38 and the supply of Merlins was not inexhaustible. The P-38 was also bigger, more expensive to build and operate, and required a larger supply chain than the P-51. A Merlin P-38 would have almost certainly been "better" than a P-51, but the P-51 was good enough, so why take on the extra expense?
No, Wright Patterson DID NOT forbid a Merlin/P-38 conversion. However, the USAAF felt the P-38 was so critical to the war effort that production delays of even a week or two were not tolerated. So the Merlin P-38 was never going to happen.
Further, putting Merlins in the P-38 would have changed the CG, for the worse, reduced the rate of climb, reduced the range, and hampered high altitude performance. The Merlin is heavier. And makes less horsepower at high altitudes than a turbocharged Allison.
The P-38 with the best engines was actually BUILT and TESTED in 1943. The P-38K, with the higher compression Allison engines capable of higher boost, and equipped with a higher RPM crankshaft, and with Hamilton Standard High Activity Paddle props, was a FAR better aircraft than any Merlin conversion could have ever hoped to be. The new model would have required a short production stoppage of less than two weeks, but the USAAF and the War Production Board denied Lockheed permission to make the swap. The P-38K was superior in performance in almost all areas to anything flying with pistons and a prop in 1943 or 1944. A top speed of around 450MPH. An operating ceiling of over 45,000 feet. A rate of climb superior to nearly anything short of an F8F Bearcat, at an initial climb rate of nearly 4800 feet per minute at MILITARY power, or, from a standing start on the runway to 20,000 feet in 5 minutes flat, in combat trim. An increase of 10% or more in range.
It never ceases to amaze me how everyone assumes Merlins would have made the P-38 better. Far from it.
P-38K