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).
Engine performance data sheet detailing horsepower, valve timing, and valve contour measurements.
| Identifier | Morton\M4.1\ img028 | |
| Date | 5th May 1919 | |
| Contd. -2- HP. HP. with open exhaust. Revs. 500 8.3 8.7 750 12.7 13.6 1000 17.3 18.9 1200 20.6 21.8 1500 24.3 26.6 1750 26.52 28.7 2000 28.3 27.8 The Valve Timing with 10 thous. clearance in the tappets is as follows:- I.O. 18° P.T.D.C. I.C. 30° P.B.D.C. E.O. 48° B.B.D.C. E.C. 4° P.T.D.C. The Valve Lift taken with no clearance at all in the tappets is .268" for the inlet and .271" for the exhaust. The Valve Contours are as follows:- Degrees on Camshaft. Inlet. Degrees on Camshaft. Exhaust. 0° .000" 0° .000" 5 .005 5 .001 10 .025 10 .003 15 .053 15 .021 20 .091 20 .043 25 .132 25 .072 30 .172 30 .118 35 .211 35 .162 40 .239 40 .200 45 .258 45 .229 50 .268 50 .253 55 .263 55 .267 60 .251 60 .271 65 .230 65 .271 70 .205 70 .271 75 .169 75 .271 80 .124 80 .270 85 .082 85 .260 90 .047 90 .244 95 .020 95 .221 100 .006 100 .182 105 .001 105 .144 110 .000 110 .099 115 .058 120 .037 125 .020 130 .001 135 .000 EH. | ||