When D. W. Onan aamp; Sons Inc. introduced their new series DRN. twin-cylinder diesel, they incorporated a new distributor-type injection pump ... The new engine is rated at 134 to 14 h.p. at 1800 r.p.m. and has a bore and stroke of 3i in. ... January, I960 Gas and Oil Power 16 Allis-Chalmers distributor-type injection pump.