example R-4360 Radial Engine with 4360 CID (72 Litres) engine displacement.
(These make any Ford engine act like a Briggs and Stratten Lawn mower Engine.)
The Wright R-3350 "Duplex-Cyclone" was one of the most powerful radial aircraft engines produced in the United States. The Pratt and Whitney R-4360 Wasp Major provided the ultimate horse power with the R-4360-43 Wasp Major developing 4400HP. This was a 28 cylinder 4 row radial engine of 4360 CID.
The R-3350 engine is an 18 cylinder two row radial four stroke engine of conventional radial design. Master conrod with individual link rods to each piston.
The first R-3350 was run in May 1937, and later versions of this engine remained in production into the early 1960s. Thousands were built to power both commercial and military aircraft during this time. Its first major military use was in the Boeing B-29 during World War II. Subsequent versions were used in the C-119, C-121 (Military Lockheed Constellation), A-1 Skyraider and the Lockheed P2V Neptune maritime patrol.
Several commercial aircraft, such as the Lockheed Constellation series L049, L649, L749, L1049 used the initial Duplex Cyclone. This was a Turbo Supercharged engine and averaged around 2700 HP for takeoff.
Later versions of the Constellation L1049E, F and the famed Super G as well as the L1649a Starliner used the Turbo compound version which developed upto 3400 HP through three power recovery turbines (blow down turbine) connected through to the engine crankshaft via a torque converter and associated gear train. These versions of the R-3350 were produced as "turbo compound" engines. Three exhaust driven turbines converted about 20% of the exhaust gas heat energy into useful power. These turbines drove a gearing mechanism that added power to the engine crankshaft. Some European truck manufacturers are claiming this as an "advance" however Curtis Wright had the answer in the 1950's.
Douglas also used the R-3350 with the DC7 series af aircraft. The DC7C "Seven Seas" used the Turbo Compund engine and along with the Constellation enabled non stop flights from the US western seaboard to Europe as well as to Australia. A typical route was the TWA Polar Route over the North pole to Europe. Fuel economy was so great that an Air France lockheed L1649a flew from California (Burbank) to Charles De Gaul in paris in 17 hours and still had 1500 gallons of petrol left from a tank capacity of 9500 gallons (US Gallons not real ones 4.5 litres)
Initial versions of the R-3350 as fitted to the Boeing B29 Bomber were equipped with carburettors. Fuel inlet mixture problems caused by unequal inlet manifolding caused severe problems with inadequate fuel mixture distrabution. (Surprisingly the Pratt and Whitney R-2800, another 18 cylinder twin row radial had dependability that the Wright engine did not have) After the Second World War the Bendix Stromberg PR-100 Injection Carburettor fuel circuit was changed from injecting the measured fuel from being delivered into the eye of the supercharger, to fuel injection pumps that delivered direct cylinder fuel injection. Reliability was increased with the final versions fitted to the Lockheed L1049G "Super Constellation", L1649A" "Starliner and Douglas DC7C "Seven Seas" proving imensly reliable with Time Between Overhauls rising to 3500 hours. Brake Specific Fuel Consumption was down to around .4 lbs fuel per horse power hour
The R-3350 is a twin row, supercharged, air-cooled, radial engine with 18 cylinders and a displacement of 3,350 cubic inches. Horsepower ranged from 2,200 to over 3,700, depending on the model. Check out www.enginehistory.org