Many of you who have an interest in World War II aviation can identify some of the iconic aircraft
of the era such as the B-25 Mitchell, the B-17 Flying Fortress, the P-47 Thunderbolt, and the P-51 Mustang. And when we hear the aircraft fly by, we are mesmerized by the sound of the big radial engines. But few have real knowledge about the development and history of American aircraft engines used during World War II.
Click on this link to reacquaint yourself with the unique sounds of a Pratt & Whitney R-4360-20 being tested after overhaul. http://vimeo.com/16117810
U.S. aircraft engines of the World War II era can be divided into two groups - those developed and produced before 1941, when war was declared on Germany and Japan, and those developed and produced during the war.
When examining aircraft engines which were available in 1941 when war was declared and then the engines that were developed specifically for the design needs of the war, there appears to be a break between the groups.
Early model engines in service before 1941:
Wright R-1820 (B-17; 92,849 built by 1944)
Pratt & Whitney R-1830 (B-24, C-47, F4F, PBY; 173,618 built)
Wright R-2600 (B-25, TBF; more than 50,000 built)
Allison V-1710 Liquid Cooled (P-39, P-40, P-38, P-51A; 70,000+ built)
Engines developed during the war:
Pratt & Whitney R-2800 (B-26, A-26, F6F, F4U, P-47; 125,334 built)
Packard V-1650 Liquid Cooled (Rolls-Royce Merlin built under license for P-51B/C/D and P-40F/L; 55,523 built)
Pratt & Whitney R-2000 (C-54; 5,028 built by 1944)
Wright R-3350 (B-29; 12,318 built by 1944)
U.S. engines whose design was begun during WWII but never saw combat in the war in any useful form include:
Pratt & Whitney R-4360
Jet engines
German jet engine development, as seen in the ME-262, was prevalent throughout the latter stages of the war in Europe. American and Allied efforts in jet technology lagged Germany and did not see significant development until war's end.
Although we have attempted to categorize engine production by prewar and during the war, there are exceptions in many cases since design and even limited production could fall outside of our basic discussion parameters. Design and development of other U.S. engines, like the 28-cylinder R-4360-20 in the video link above, began during World War II, but they often didn't see widespread use until after the war. The R-4360 was used in a variety of post-war planes, including the B-50, B-36, P4M and C-97. U.S. companies also developed jet engines during the war, but no U.S. jet aircraft saw combat in World War II.
Pratt & Whitney and Wright dominated U.S. aircraft engine production from the 1930s through the war years. Although wartime production of liquid-cooled engines by Allison and Packard was certainly significant, it wasn't as great as the production of air-cooled, or radial, engines by Pratt & Whitney and Wright. Before the war, U.S. engine technology focused on transport and airline requirements, with most engines in the 1,000 horsepower range. With the onset of war there was a sudden demand for fighter and bomber engines with substantially more horsepower and reliability.
The unique feature concerning aircraft engines as compared to aircraft production was that aircraft engines contained many of the same parts (cylinders, pushrods, pistons, etc.) whereas the actual airplane had thousands of parts unique to the location and purpose on the aircraft.
As the war effort went into high gear, the two prime engine manufactures realized they could not keep up with engine requirements even considering planned physical plant expansions. The concept of licensing engine production and parts without losing control of assembly and ownership was reluctantly accepted by the prime manufacturers. Under tightly controlled licensing arrangements, many other companies became responsible for partial or complete engine production. Ohio Crankshaft Company, Otis Elevator Company, Hudson Motor Car Company, Eaton Manufacturing, Graham Paige Motors, Studebaker Corporation, Chrysler Corporation, Continental Motors, Ford, Buick, Nash, Chevrolet, and Jacobs Aircraft Engine Company all played vital roles.
Companies of the U.S. industrial base pulled together to ensure production and delivery of massive quantities of engines to support the expanding aircraft production for both the European and Pacific war effort. From this home front effort evolved high levels of standardization, improved production tolerances, and increased quality and reliability. Pratt & Whitney and Wright may have been the biggest U.S. manufacturers of aircraft engines, but the war could not have been won without the committed support of many others.
Under the license arrangement, Pratt & Whitney and Wright found their organizations spending more time on research and development, production process, and quality assurance duties. Wright was affected by this more than Pratt & Whitney. Actual engine production by both companies fell as they were forced to address administrative issues, production line design, and vendor supply problems.
Engines produced by our British allies were often hand-built rather that mass produced which introduced problems of interchangeability and metric versus SAE parts.
Please visit this link for more information on the challenges of aircraft engine production during the war. This important source matches aircraft to engines and details many of the technical challenges of the production process across America. You can also take a look at this website for World War II U.S. aircraft engine manufacturing sites and other data.
When you visit your next airshow and get up close to your favorite warbird, chances are that the engine data plate-which tells where the engine was assembled, produced or modified--will say Pratt & Whitney or Wright. If you see Otis or Nash, take lots of pictures.
Based on his travels, Ed and his wife, Susan, chose Colorado Springs as their retirement location and arrived on 911. Since that historic day, Ed has been involved with the Peterson Air and Space Museum on Peterson Air Force Base assisting with the restoration of their P-47 Thunderbolt. After making a parts run across the airport to the National Museum of World War II Aviation, Ed has been a valued volunteer in the restoration of gun turrets and other artifacts to pristine condition.
Women Airforce Service Pilots were key to our war efforts on the home front. Perhaps you know a WASP with artifacts and a compelling history which deserves the attention of our visitors and research scholars.