Re: The Engine that Won the War

Posted by Stephen Houseknecht On 2012/3/15 18:42:00

Packard building the Merlin under license from Rolls Royce has an interesting story behind it. Going back to the 1920's the Curtiss D-12 was the aviation engine to beat both here in the US, England, France and Italy. It had a near monopoly on high performance aircraft engines until the radial air-cooled Pratt& Whitney Wasp appeared in 1925. After the D-12 had won the Schneider Cup races in 1923, the British aircraft engine builders, Napier and Rolls both took a look at the D-12

"To make sure that there would be no mistake as to what
the Air Ministry wanted, a complete D-12 was loaned to Rolls-Royce.
Following the new classical lines of low frontal area and overall compactness,
the design of a new aluminum monoblock V-12 that would
supplant the D-12 took shape quickly. The prototype appeared in
March 1926.." pg97

Rolls came up with the F-X which became the Kestrel, which became the Merlin.
A Rolls Royce 1300hp Merlin was installed on a P-40E and flown in November 1941which improved higher altitude performance with the two-stage supercharger. This became the P40F with 1300 built using Packard Merlins. The USAAF allocated the Packard Merlin to the P-51 program to replace the Allison V-1710 and the P-40 went back to Allisons. The US Government was also paying RR a $650 royalty for every Packard Merlin built and the P-40 was on the way out anyway. Equipping the P-51D with the two-drop tanks finally gave it the range needed to escort the 8AF bomber streams over Germany and to freelance on the way back.
Link to PDF "The Curtiss D-12 Aero Engine" Smithsonian Air and Space Museum #7
AIRCRAFT PROPULSION
www.sil.si.edu/smithsoniancontributions/.../pdf.../SAOF-0001.4.pdf


That Spit pass always gives me a kick. Have you ever seen the CAF Texas Raiders B-17 buzz job with the Texas anti-littering campaign?