aero engines

Allison W3420s
Allison F-80 Trijet
Allison V-1710 Turbo-Compound
Clerget Rotary Engine
Curtiss Chieftain
Curtiss OX-5
Daimler-Benz DB 605
Gnome Monosoupape
Lycoming XR-7755
Pratt & Whitney R-2800
Wright J-5 Whirlwind
Wright Cyclone
Wright Hispano-Suiza

Wright Hispano-Suiza E-2 & E-4 - USA

Fig 1. Wright Hispano-Suiza Aviation Engine, Model E-2.

Wright Water-Cooled Engines. Improvements made by the Wright engineers have produced an aircraft engine that will operate for longer periods at higher mean effective pressures than any other type of internal combustion engine. Several types weighing less than 2 1/2 pounds per horsepower have run for periods of from 200 to 300 hours with but little attention. The Wright E4, with the same crankcase assembly, the cylinders only being changed, ran for 572 hours without attention of any kind. Compared with the original Model A, built 10 years ago, the present engine with approximately the same weight and same displacement develops one third more power, operates at 24 per cent more speed and has 3,000 per cent greater durability.


Fig 2. Wright 200 Horsepower Aviation Engine, Model E-4 has Eight Water-cooled Cylinders in Two Blocks of Four.

During WW I, exhaust valves, connecting rod big end bearings and spark plugs gave the most trouble. In cylinder construction three difficulties presented themselves: (a) the valves warped and burned, (b) the valve seats did not remain true and (c) in long runs the valves hammered into the seats so that the tappet clearance was lost and the valves were held open. The present type of Wright cylinder as shown at Fig. 165 D and the use of tulip head silchrome steel valves have greatly reduced valve troubles. Refinement of details of the 1,947 cubic inches 60 degree V-type 12-cylinder Wright T-3 engine has enabled it to be used satisfactorily at speeds greater than 2,200 r.p.m. and to develop 750 horsepower with approximately 140 pounds mean-effective pressure at 20 per cent less weight per horsepower than that of the original engine.

Fig 2. Wright "Tempest" E-4 water-cooled engine viewed from the rear showing magneto mounting and water pump location.

The Wright E2 engine, shown at Fig. 1 is no longer in production but it was a popular type for some years. This engine has practically all of the characteristics of the Hispano-Suiza as previously described. The improved and refined Wright E4 shown at Figs. 2, 3 and 4 is the type that has been operated for 310 hours with one cylinder assembly, or long enough to have driven an airplane 31,000 miles without overhauling. After a new set of cylinders had been fitted, the other parts were run an additional amount so that the equivalent of 57,200 miles operation was obtained with only minor external adjustments. The old Model A engines developed a maximum of 175 horsepower at 1,800 r.p.m. whereas the latest models of the same type develops a maximum of 285 horsepower at 2,300 r.p.m. The bore of the E4 cylinders is 4,710 inches, the stroke is 5,110 inches and the total displacement is 718 cubic inches. This engine is no longer in production, all demands for this horsepower being supplied with radial air-cooled engines.

Fig 4. Top view of the Wright "Tempest" E-4 water-cooled engine showing carburettor and induction manifolding.