Daimler-Benz DB 604
The Daimler-Benz DB 604 was an experimental German 24-cylinder aircraft engine, which did not progress beyond the initial engine testing phase and was ultimately abandoned in 1942.
Design and development
The DB 604 was unique among the Daimler-Benz [DB 600 series|DB 600 series] of aircraft engines for having its 24 cylinders arranged in an X, with four inline rows of six cylinders. The DB 604 was also unique amongst the X-24 engines, in that it was not conceived as a further development of existing Daimler-Benz aircraft engines such as the DB 601, DB 603 or DB 605, which themselves had been twinned up as two separate powerplants sharing a new common gear reduction case at their front ends, into the 1.5-tonne dry weight DB 601-based "coupled" DB 606 in February 1937, the same-weight figured DB 605-based DB 610 by June 1940, and just slightly earlier, in March 1940, the 1.8 tonne approximate weight replacement for the DB 606 and 610, the DB 603-based DB 613 "power system" of nearly 3,500 PS output. For example, the Rolls-Royce Vulture was basically two Rolls-Royce Peregrine engines joined at the crankcase, thus producing the X-configuration of the cylinders.The DB 604 was a completely new Daimler-Benz engine design featuring a perfectly square stroke ratio of 135 mm x 135 mm. The short stroke ratio enabled the relatively high engine speed of 3,200 rpm. The first engine tested in 1939 on the engine test stand achieved a power output of 1,725 kW.
Further development of the first test engines led to the DB 604A/B. The only difference between the DB 604A and the DB 604B - as with the similarly suffixed A and B versions of the DB 606 and 610 "coupled" power system engines - was the direction in which the DB 604's crankshaft turned. The DB 604A/B was equipped with a two-speed supercharger, achieving 1,835 kW whilst testing.
Development of the DB 604 was canceled by the Reich Air Ministry in September 1942.