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).
The results and future expectations of power output tests on a Continental Phantom II engine.
| Identifier | ExFiles\Box 19\1\ Scan103 | |
| Date | 23th May 1931 | |
| γ/7120. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} c. MOR. Da.{Bernard Day - Chassis Design} c. E.{Mr Elliott - Chief Engineer} Ev.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/RmL/AD23.5.31. CONTINENTAL P.II. POWER OUTPUT. X.7120. X.7771. We have had a run on a standard P.II. low compression engine fitted with twin carburetters and a camshaft having R.{Sir Henry Royce} engine cam forms. The timing was I.O. 17º B.T.D.C. E.O. 56º B.B.D.C. I.C. 59.5º A.B.D.C. E.C. 18.6º A.B.D.C. .020 tappet clearance. The carburetter chokes were on the small side giving over 3" depression at 3,000 R.P.M. We increased the power at 3000 R.P.M. from 129.8 with the standard camshaft to 155.5 with the aero camshaft, both open exhaust. The M.E.P. at 750 R.P.M. with this increased top power output was 93 lbs/sq.in. or approx. the same as the cars we are now turning out as standard. With large chokes and 5 - 1 C.R. we expect no difficulty in getting 175 H.P. at 3000 R.P.M. With a single carburetter arranged for power at high rather than low speeds (the existing Carb is designed to give maximum M.E.P. for touring as opposed to sports purposes at 1500 R.P.M.), we anticipate a further 10 H.P. would be available. We shall confirm these figures during the next few days, also the best timing. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||