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).
Power comparison chart for two different camshafts, showing BHP, BMEP, and induction pipe depression against RPM.
| Identifier | ExFiles\Box 124\2\ scan0009 | |
| Date | 9th December 1939 | |
| CAMSHAFT COMPARISON B 80 S 113 9-12-39 POWER "ETHYL" PETROL COMP RATIO G 2 : 1 INDUCTION PIPE ExS 925 (1.600 DIA BORE) CARB. A.A.25 DUPLEX STROMBERG WITHOUT AIR SILENCER PISTONS EB 3916 (STD AEROLITE) ① CAMSHAFT EB 4105 (TIMING @ .030 CLEARANCE) I.O. 1.2° ATDC. E.O. 42.5 BBDC. I.C. 39° ABDC E.C. 4° BTDC ② CAMSHAFT EB 4512 (TIMING @ .030" CLEARANCE) I.O. 11° ATDC E.O. 41.5° BBDC I.C. 30° ABDC E.C. 4.2° B.T.D.C. a.{Mr Adams} OPEN EXHAUST b. SILENCED (B.II. EXH. SILENCER COMPLETE) ① IND PIPE DEPRESSION INS Hg Vertical Axis Left: B.H.P. Vertical Axis Right Top: B.M.E.P. Vertical Axis Right Bottom: INDUCTION PIPE DEPRESSION INS. Hg. Graph Curves labelled: 1a, 2a, 1b, 2b RM{William Robotham - Chief Engineer} / F.J. HALLAM | ||