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).
Technical data sheet comparing camshaft performance metrics for various engine units.
| Identifier | ExFiles\Box 113\5\ scan0219 | |
| Date | 26th May 1941 | |
| To Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} Copy to Jnr.{Charles L. Jenner} Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} Camshaft file 1004 GENERAL INFORMATION ON CAMSHAFTS A - MAX. ACCELERATION AND DECELERATION. in feet/sec² @ 1000 R.P.M. | Engine Unit | Rocker Ratio | Max. + u2 accel. of inlet VALVE | Max. + u2 accel. of inlet CAM | Max.decel. of inlet VALVE | Max.decel. of inlet CAM | Max.accel. of.inter. VALVE at max.engine speed | |--------------|--------------|-------------------------------------|-----------------------------------|-----------------------------|---------------------------|--------------------------------------------------| | Bentley II | 1.245 | 2952 | 2370 | 960 | 770 | 59600 @4500 RPM. | | Bentley V | 1.31 | 3180 | 2430 | 906 | 692 | 64300 @4500 RPM. | | Bentley 60 | 1.28 | 4043 | 3160 | 1071 | 837 | 81500 @4500 RPM. | | Myth | 1.3 | 3000 | 2310 | 651 | 500 | 67800 @4750 RPM. | | Merlin | 1.5 | 3870 | 2580 | 1104 | 737 | 50400 @3600 RPM. | B - TAPPET VELOCITY WHEN MEETING AND LEAVING THE TOE OF THE CAM. In feet/sec. @ 250 R.P.M. | Engine Unit | INLET | | EXHAUST | | |--------------|-------------------------------------|-------------|-------------------------------------|-------------| | | OPENING Cam strikes tappet. | CLOSING Cam leaves tappet. | OPENING Cam strikes tappet. | CLOSING Cam leaves tappet. | |--------------|-------------------------------------|-------------|-------------------------------------|-------------| | Bentley II | at .083 ft/sec. | at .06 ft/sec. | at.083 ft/sec. | at .06 ft/sec | | Bentley V | .114 | .057 | .114 | .057 | | Bentley 60 | .081 | .059 | .103 | .075 | | Myth | .103 | .058 | .103 | .075 | | Merlin | .146 | .146 | .146 | .146 | | ||