From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparative table of constructional details for P.V.G., Rudge, and Bentley engines.
| Identifier | ExFiles\Box 133\1\ scan0011 | |
| Date | 2nd March 1936 guessed | |
| -6- Constructional Details - Rudge, Bentley & P.V.G. | | P.V.G. | Rudge | Bentley | |---|---|---|---| | Bore | 5.000" | 3.346" | 3.250" | | Stroke | 5.500" | 3.464" | 4.500" | | Inlet valve dia. | 1.625" | 1.200" | 1.400" | | Total inlet area | 4.150 m² | 2.250 m² | 1.540 m² | | Exhaust valve diam. | 1.425" | 1.100" | 1.300 | | Total exhaust area | 3.180 m² | 2.100 m² | 1.322 m² | | Ratio, piston/area/exhaust area. | 6.180 | 4.200 | 6.250 | | Ratio, piston area/inlet area | 4.720 | 3.950 | 5.390 | | No. of valves | 4 | 4 | 2 | | Plug position | 2 exhaust | Central | Side | | Maximum B.M.E.P. | 134 | 152.0 | 124 lbs/in | | R.P.M. for max. torque | 2400 | 4250 | 2600 | | Piston speed for max.torque. | 2200 | 2460 | 1950 ft/in | | Piston speed for max.power. | 3370 | 3500 | 3000 ft/in | | Inlet gas velocity (max. torque). | 140 | 162 | 175 ft/sec | | Inlet gas velocity (max. power). | 236 | 230 | 270 ft/sec | | Exhaust gas velocity (max.torque). | 183 | 172 | 203 ft/sec | | Exhaust gas velocity (max.power) | 309 | 245 | 312 ft/sec | | Compression ratio. | 6.00 | 7.30 | 6.50 | | ||