Aviation of World War II
The BMW 801D
The BMW 801D-2 14-cylinder radial twin-in-line engine with direct fuel injection had a rated power of 1,460 hp. and takeoff power 1,700 hp. The slightly lower power in comparison with American and Soviet air-cooled engines is explained by the fact that the German engine was designed for low-octane C-3 gasoline with an octane rating of 95, and this forced the designers to limit the afterburner on boost.
The motor was cooled by a 12-blade fan mounted directly behind the propeller and driven from the propeller by a step-up gear. Each cylinder had carefully fitted baffles on the liner and on the head. Cooling air exited through slots on the side and bottom of the bonnet, as well as through adjustable slots in the side bonnet covers.
The exhaust system consisted of 12 pipes. 10 cylinders had individual jet pipes, and the four lower cylinders were paired. Individual pipes were brought out four on each side of the engine in front of the adjustable flaps of the cooling system in such a way that the cooling air formed a layer between the exhaust gases and the cab skin, preventing the latter from heating. Four pipes from the six lower cylinders were brought out “under the belly”.
Motors were most often supplied complete with hoods, underwater pipes, and if necessary, with tropical filters, with an oil cooler and an oil tank, as well as with the front ring of the motor mount, which simultaneously served as a reservoir for the liquid used in the automatic control of the propeller group. Such a kit was indicated by the addition of the letter T (Triebwerksanlage) to the engine brand: BMW 801TD.
Automatic propeller VDM 0-12176 А-3, constant speed, metal, wide-bladed (maximum blade chord - 315 mm), had a diameter of 3.3 m.On airplanes with BMW 801TS / TU, another propeller was used: VDM 9-12175 Н- 3 with a diameter of 3.5 m with Heine wooden blades.
The motor and the propeller were controlled by an automatic machine, which provided the adjustment of the basic parameters of the motor and propeller to the most advantageous values when operating with one lever. Depending on the position of the gas sector, the machine selected boost pressure, fuel supply, ignition timing, supercharger speed switching and propeller pitch.