MERCEDES-BENZ DB-601A AIRCRAFT ENGINE - (Design Features and Performance Characteristics) 410131
THE major part of this paper reports a teardown inspection of the Mercedes-Benz DB-601A engine with detailed descriptions and comments on some of the design features of major component parts. It is followed by a check of the magnaflux inspection method, analysis and comparison of materials, and comparison on quality of finish.
Quoting specifications, the author reveals that the Mercedes-Benz DB-601A engine is an inverted 60-deg V-type, 12-cyl in banks of 6, liquid-cooled Otto-cycle engine with fuel injection. Its bore and stroke are 150 x 160 mm; its displacement is 2070 cu in; and its compression ratio is 6.74:1.
Comparing the physical and performance characteristics of the engine with contemporary American, British, French, and German powerplants of the same general design, Mr. Young reports that German and French liquid-cooled designs tend toward larger displacement and lower crankshaft speed while American and British practice favors higher engine speeds with relatively smaller piston displacement; that the Germans favor the inverted type of construction in in-line engines because of the excellent visibility which this type of engine permits in a single-engine airplane; and that American and British engines average about 5.7% higher in bmep under military rating.
Discussing workmanship and quality of finish in his conclusions, Mr. Young points out that no useless effort in man-hours or finish has been expended where there is not a direct return in increased reliability and performance, and that handiwork in the polishing of stressed parts is of the highest order. Although stating that the design represents good mass-production practice for military aircraft engines, he notes that the highly stressed bolts do not have ground threads.
On the important factor of performance, he summarizes: “Despite wishful thinking to the contrary, the performance of the DB-601A with respect to sea level and altitude output, fuel consumption, and weight, seems to be on a par with contemporary powerplants of the same general type.”
Discussions of this paper were presented by W. H. Sprenkle and E. K. Von Mertens, both of Pratt & Whitney Aircraft, Division of United Aircraft Corp., but were not prepared for publication.
