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SOURCE: THE 456th FIGHTER INTERCEPTOR SQUADRON WEBSITE, RADIAL ENGINE PAGE
SOURCE URL: The Radial Engine
Lot of basic info on radial engines. Of particular interest to me was the info on the Lycoming XR-775 which is near the bottom of the linked page.
The article is below but I suggest linking back to the original for the photographs.
========================================================
The displacement was 7,755 cubic inches. When compared to Lycoming's largest production engine in production today which displaces 720 cubic inches, it was more than 10 times larger!
This huge engine was 10 feet long, 5 feet in diameter and weighed 6,050 pounds. It produced 5,000 HP at 2,600 RPM, and the target was 7,000. It used 580 GPH (gallons per hour)of aviation gas at the 5,000 HP rating.
There were nine overhead camshafts which could be shifted axially for METO power in one position and cruise at the other. Two great shafts emerged for coaxial propellers, and there was a two speed gear-change box between the crankshaft and the propeller shafts.
Development of the XR-7755 began at Lycoming in Williamsport in the summer of 1943. With the end of World War II in 1945, the military no longer had a need for an engine of this size, and development of the XR-7755 stopped at the prototype stage.
Experimental Engineers with the XR-7755 Here is the XR-7755 in the test cell at Lycoming along with the team of experimental engineers responsible for its testing and qualification. Photo courtesy Robert Ribando. William Ribando can be seen in the white shirt and tie just to the left of the engine.
During those years, Lycoming put together a team, under the leadership of VP Engineering Clarence Wiegman, to develop this super-size engine.
The engine now resides at Silver Hill of the Smithsonian Institute
The displacement was 7,755 cubic inches. When compared to Lycoming's largest production engine in production today which displaces 720 cubic inches, it was more than 10 times larger!
This huge engine was 10 feet long, 5 feet in diameter and weighed 6,050 pounds. It produced 5,000 HP at 2,600 RPM, and the target was 7,000. It used 580 GPH of av gas at the 5,000 HP rating.
There were nine overhead camshafts which could be shifted axially for METO power in one position and cruise at the other. Two great shafts emerged for coaxial propellers, and there was a two speed gear-change box between the crankshaft and the propeller shafts.
Development of the XR-7755 began at Lycoming in Williamsport in the summer of 1943. With the end of World War II in 1945, the military no longer had a need for an engine of this size, and development of the XR-7755 stopped at the prototype stage.
Experimental Engineers with the XR-7755 Here is the XR-7755 in the test cell at Lycoming along with the team of experimental engineers responsible for its testing and qualification. Photo courtesy Robert Ribando. William Ribando can be seen in the white shirt and tie just to the left of the engine.
During those years, Lycoming put together a team, under the leadership of VP Engineering Clarence Wiegman, to develop this super-size engine.
The engine now resides at Silver Hill of the Smithsonian Institute
SPECIFICATIONS:
DISPLACEMENT = 7755 CUBIC INCHES (127 LITERS)
# OF CYLINDERS = 36
BORE & STROKE = 6.4 in. (162 mm) x 6.8 in. (171 mm)
WEIGHT = 6,050 lbs. (2,744 kg)
HORSEPOWER = 5,000 hp (3,728 kw) at 44 in Hg.MP.
RPM = 2600
CONFIGURATION = 4-cycle, 4 row radial, liquid cooled, 2 speed geared dual rotation propeller drive with turbo-supercharger.
SOURCE URL: The Radial Engine
Lot of basic info on radial engines. Of particular interest to me was the info on the Lycoming XR-775 which is near the bottom of the linked page.
The article is below but I suggest linking back to the original for the photographs.
========================================================
The displacement was 7,755 cubic inches. When compared to Lycoming's largest production engine in production today which displaces 720 cubic inches, it was more than 10 times larger!
This huge engine was 10 feet long, 5 feet in diameter and weighed 6,050 pounds. It produced 5,000 HP at 2,600 RPM, and the target was 7,000. It used 580 GPH (gallons per hour)of aviation gas at the 5,000 HP rating.
There were nine overhead camshafts which could be shifted axially for METO power in one position and cruise at the other. Two great shafts emerged for coaxial propellers, and there was a two speed gear-change box between the crankshaft and the propeller shafts.
Development of the XR-7755 began at Lycoming in Williamsport in the summer of 1943. With the end of World War II in 1945, the military no longer had a need for an engine of this size, and development of the XR-7755 stopped at the prototype stage.
Experimental Engineers with the XR-7755 Here is the XR-7755 in the test cell at Lycoming along with the team of experimental engineers responsible for its testing and qualification. Photo courtesy Robert Ribando. William Ribando can be seen in the white shirt and tie just to the left of the engine.
During those years, Lycoming put together a team, under the leadership of VP Engineering Clarence Wiegman, to develop this super-size engine.
The engine now resides at Silver Hill of the Smithsonian Institute
The displacement was 7,755 cubic inches. When compared to Lycoming's largest production engine in production today which displaces 720 cubic inches, it was more than 10 times larger!
This huge engine was 10 feet long, 5 feet in diameter and weighed 6,050 pounds. It produced 5,000 HP at 2,600 RPM, and the target was 7,000. It used 580 GPH of av gas at the 5,000 HP rating.
There were nine overhead camshafts which could be shifted axially for METO power in one position and cruise at the other. Two great shafts emerged for coaxial propellers, and there was a two speed gear-change box between the crankshaft and the propeller shafts.
Development of the XR-7755 began at Lycoming in Williamsport in the summer of 1943. With the end of World War II in 1945, the military no longer had a need for an engine of this size, and development of the XR-7755 stopped at the prototype stage.
Experimental Engineers with the XR-7755 Here is the XR-7755 in the test cell at Lycoming along with the team of experimental engineers responsible for its testing and qualification. Photo courtesy Robert Ribando. William Ribando can be seen in the white shirt and tie just to the left of the engine.
During those years, Lycoming put together a team, under the leadership of VP Engineering Clarence Wiegman, to develop this super-size engine.
The engine now resides at Silver Hill of the Smithsonian Institute
SPECIFICATIONS:
DISPLACEMENT = 7755 CUBIC INCHES (127 LITERS)
# OF CYLINDERS = 36
BORE & STROKE = 6.4 in. (162 mm) x 6.8 in. (171 mm)
WEIGHT = 6,050 lbs. (2,744 kg)
HORSEPOWER = 5,000 hp (3,728 kw) at 44 in Hg.MP.
RPM = 2600
CONFIGURATION = 4-cycle, 4 row radial, liquid cooled, 2 speed geared dual rotation propeller drive with turbo-supercharger.