The B-5 was a development of the earlier K-5 with slightly greater power and dimensions. The main change was the increase in cylinder bore from 108 mm to 117 mm and a corresponding increase in displacement from 372 cu in to 441cu in. One difference the B-5 had from radial engines of other manufacturers was that each individual cylinder had its own camshaft, a system also used by the contemporary Soviet-built, 8.6 litre-displacement Shvetsov M-11 five cylinder radial, while most other radial engine designs used a "cam ring" for the same purpose, connected to every cylinder's valves. The B-5 was a roughrunning but reliable engine. The B-5 and its derivatives were produced in the thousands, powering many World War IItrainer aircraft; its military designation was R-440. The B-5 was followed by the R-5 and R-55.