The manufacturer of the excellent engines "Pob-joy", Mr. D. Pobjoy, founded a new engine factory, "DRP Engines Ltd", and under license from Ricardo Company they produced three valveless engines, the "Meteor", the "Velox" and the "Excelsior".

"DRP - Velox"

-They could run from 800 to 1,000 hrs without overhaul thanks to special lubrication devices.

-The "Meteor" had 4 cylinders in line, was cooled by air, and gave 100 hp at 3,600 rpm and 110 hp at 4,000 rpm.

-The "Velox" had two groups of 4 cylinders in inverted V. It gave 260 hp on land and 240 hp at altitude, and it was somewhat over-compressed.

-The "Excelsior", in "X", was designed in two series: the B giving 480/560 hp and the M.S., which was overcompressed, giving 540 hp at 2,500 meters of altitude and 600 hp at takeoff.

From Appendix 6: We have located a block and cylinders for a "Velox" before being mechanized, that is to say in the rough casting, and where we can see the complexity of the whole.

"DRP Velox cast"

-The crankshaft output is simulated.