The 802 emerged with an almost identical displacement to the American 18-cylinder Wright R-3350 Duplex-Cyclone and just 54 cm3 (3.3 cu in) larger than the British Bristol Centaurus.
One problem with the 801 was its poor altitude performance, due almost entirely to its single-stage two-speed, mechanically driven supercharger.
Since the 802 was not a necessity given the success and emerging flexibility of the 801's basic design, the engineers decided to take the time needed to address this problem by including an improved two-stage,[1] three-speed supercharger.
[2] A twelve-blade fan, almost identical in appearance to the 801's, and stator compressed incoming air, then fed some into the supercharger.
[3] The combination of the fan and ejector thrust from the exhaust balanced the total internal engine drag.
With their BMW 003 axial-flow turbojet engine finally maturing and considerably larger models of turbojet and even turboprop powerplants entering the prototype phase from both BMW and their competitors, it appeared that large piston engines weren't worth building.