Readers' Choice: 50 Amazing Aircraft Engines

From a list of five remarkable powerplants, you can choose one to add to our 50 Amazing Aircraft Engines gallery of honor.

The other week when we published our latest Flying list, 50 Amazing Aircraft Engines, we knew we'd get some heat for engines we left off the list, and we were right. There were, in fact, a few engines that we considered but ultimately left off the list that readers took us to task for. So, in the spirit of getting things right and giving you a voice in the matter, we're asking you to select one more engine to add to the list from a group of powerplants that didn't make the original list and that were brought to our attention by our readers.

Each engine vying for inclusion has a remarkable story, both from a technological and historical perspective. You get to decide which is most remarkable.

To cast your vote, click through the images.

50 Amazing Aircraft Engines Readers' Choice

51 Amazing Aircraft Engines?

Wright 3350 Double-Cyclone Engine

Wright 3350 Double-Cyclone Engine

The Wright-Double Cyclone took radial piston engine technology to its very limits, essentially mating two already powerful Wright Cyclone 9-cylinder engines into an 18-cylinder twin-row powerhouse. In one modern application — the highly modified Grumman Bearcat Reno racer Rare Bear — the two-plus ton dry weight engine can produce as much as 4,000 horsepower, though typical power output was around a third of that. Wright had begun developing the engine in the mid-1930s, but it wasn't until the need for an ultra-long range and high altitude bomber, the Boeing B-29, came to pass that Wright completed the engine. After a lot of work to improve its reliability, the 3350 would go on to power not only the Superfortress but a number of the most influential early airliners, including the Lockheed Constellation and Super Constellation and the Douglas DC-7. Click through to see the rest of the photos or vote now by clicking on your favorite engine below. Vote for the Wright 3350 Double-Cyclone Engine
Vote for the Wright Whirlwind
Vote for the Allison/Rolls-Royce 250
Vote for the Rolls-Royce Pegasus
Vote for the Pratt & Whitney J57
Wright Whirlwind

Wright Whirlwind

The Wright Whirlwind was a series of air-cooled engines of varying horsepower that had their origin in the nine-cylinder, 200-horsepower Lawrance J-1, developed in the early 1920s by American engineer Charles Lanier Lawrance. The U.S. Navy had positive results with the J-1 and, because it had reservations about working with a small company, it urged Wright Aeronautical Corporation to buy Lawrance's company. While Lawrance continued to work on the engines and stayed on as chief engineer, Wright renamed the engine series. Wright Whirlwinds were produced with anywhere from five to 14 cylinders, cylinders that also changed shaped as the engine models progressed. The most popular engine in the series was the J-5. With the desirable combination of being lightweight, efficient and reliable, the J-5 was selected by Charles Lindbergh to power The Spirit of St. Louis, the airplane that would carry him across the Atlantic. (National Air and Space Museum photo) Click through to see the rest of the photos or vote now by clicking on your favorite engine below. Vote for the Wright 3350 Double-Cyclone Engine
Vote for the Wright Whirlwind
Vote for the Allison/Rolls-Royce 250
Vote for the Rolls-Royce Pegasus
Vote for the Pratt & Whitney J57
Allison/Rolls-Royce 250

Allison/Rolls-Royce 250

With more than 30,000 engines produced, the Allison/Rolls-Royce 250 is one of the most successful small turboshaft engines ever made. It has powered more than 170 types of helicopters and airplanes, including rotorcraft such as the Bell 206, Sikorsky S-76, Eurocopter AS350 and MD Helicopters MD 500 and fixed-wing aircraft including the Extra EA-500 and Prop-jet conversions of the Beech Bonanza. Allison first began producing the 250 series in the 1960s, starting out with engines in the 400 shp range and introducing ever more powerful versions up to 750 shp. Rolls-Royce bought the design in 1995, and subsequently introduced a downrated variant, the 300 shp RR300 that powers the Robinson R66. The Model 250 engine is still being produced today, with more than 16,000 in service around the world. Click through to see the rest of the photos or vote now by clicking on your favorite engine below. Vote for the Wright 3350 Double-Cyclone Engine
Vote for the Wright Whirlwind
Vote for the Allison/Rolls-Royce 250
Vote for the Rolls-Royce Pegasus
Vote for the Pratt & Whitney J57
Rolls-Royce Pegasus

Rolls-Royce Pegasus

Thousands of airshow visitors have been wowed by the performance of the Hawker Harrier jet hovering, bowing and sidestepping left and right in front of the show center, landing vertically and then taking off nearly like a rocket. But this mind-blowing performance would not be possible without the Rolls-Royce Pegasus engine that powers the airplane. Initially developed in the late 1950s by British engine maker Bristol Siddeley for the Hawker Siddeley P.1127, an experimental aircraft that led to the Hawker Harrier, the Pegasus project was eventually taken over by Rolls-Royce. More than 1,200 Pegasus engines have accumulated more than two million flight hours, and the Pegasus keeps evolving. The latest variant of the engine is controlled by a FADEC system and is capable of producing 23,800 pounds of thrust, which can be vectored to propel the aircraft forward or vertically through four swiveling nozzles. Click through to see the rest of the photos or vote now by clicking on your favorite engine below. Vote for the Wright 3350 Double-Cyclone Engine
Vote for the Wright Whirlwind
Vote for the Allison/Rolls-Royce 250
Vote for the Rolls-Royce Pegasus
Vote for the Pratt & Whitney J57
U.S. Navy
Pratt & Whitney J57 (JT3)

Pratt & Whitney J57 (JT3)

The Pratt & Whitney J57 leapfrogged the competition when it arrived on the scene in 1952 as a new and more potent twin-spool, axial flow turbojet engine. It started out powering the North American F-100 Super Sabre, the first production airplane capable of breaking the speed of sound in level flight. That feat earned it the prestigious Collier Trophy for the greatest achievement in aviation. The J57 went on to set speed records in the Convair F-102 Delta Dart and Chance Vought F8U-1 before evolving into its best remembered roles — as the power behind the Boeing B-52 Stratofortress, Lockheed’s U-2 spy plane and, with the JT3 commercial version of the J57, as the engine that ushered in the age of the transoceanic jetliner with the inaugural flight of a Pan Am Boeing 707 from New York to Paris in 1958. In all, Pratt & Whitney produced more than 27,000 J57/JT3 engines between 1953 and 1965, when the last was shipped. Click through to see the rest of the photos or vote now by clicking on your favorite engine below. Vote for the Wright 3350 Double-Cyclone Engine
Vote for the Wright Whirlwind
Vote for the Allison/Rolls-Royce 250
Vote for the Rolls-Royce Pegasus
Vote for the Pratt & Whitney J57
State Archives of Florida, Florida Memory
50 Amazing Aircraft Engines

50 Amazing Aircraft Engines

Time to cast your vote for your favorite engine! Click one of the links below. Vote for the Wright 3350 Double-Cyclone Engine
Vote for the Wright Whirlwind
Vote for the Allison/Rolls-Royce 250
Vote for the Rolls-Royce Pegasus
Vote for the Pratt & Whitney J57
Check out our full list of 50 Amazing Aircraft Engines here.