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 performance graph comparing two different camshafts with and without a silencer, using 'Ethyl' petrol.
| Identifier | ExFiles\Box 124\2\ scan0010 | |
| Date | 9th December 1939 | |
| CAMSHAFT COMPARISON B. 80 POWER S. 114 9.12.39 "ETHYL" PETROL COMP. RATIO 6.2 : 1 INDUCTION PIPE EXS. 925 (1.600 DIA. BORE) CARB. AA.{D. Abbot-Anderson}25 DUPLEX STROMBERG, WITHOUT AIR SILENCER. PISTONS E.B.3916 (STD AEROLITE) ① CAMSHAFT E.B.4105 (TIMING @ .030" CLEARANCE) I.O. 12° A.T.D.C. E.O. 42.5° B.B.D.C. I.C. 39° A.B.D.C. E.C. 4° B.T.D.C. ② CAMSHAFT EX.33975 (TIMING @ .030 CLEARANCE) I.O. 11.2° A.T.D.C. E.O. 46.5° B.B.D.C. I.C. 31.5° A.B.D.C. E.C. 9° B.T.D.C. ⓐ OPEN EXHAUST ⓑ SILENCED (B II. EXH. SILENCER COMPLETE) Axis Labels: B.H.P. R.P.M B.M.E.P. INDUCTION PIPE DEPRESSION INS. HG. Graph Labels: IND. PIPE DEPRESSION INS. HG. Signed: RM{William Robotham - Chief Engineer} / F.J. HALLAM | ||