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).
Comparison of a 116° camshaft against a standard 110° camshaft on a Standard China Engine.
| Identifier | ExFiles\Box 5a\5\ 05-page228 | |
| Date | 12th November 1929 | |
| COPY. X5771. To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/ACL. c. Sr. c. Wcr. E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Ev.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/ACL9/AD12.11.29. X.5771. X.5090. 116° CAMSHAFT ON STANDARD CHINA ENGINE. We have compared the 116° camshaft (E.55362) with the Std. 110° camshaft on the Std. China engine. Curves are given on appended print V.745. The increase of power at the high speeds given by the 116° camshaft is not so marked on the Std. engine as when used in conjunction with larger valves and a larger carburetter as shewn in our report of 5.11.29. In this case we get an increase at max. power of 2.3% whereas on the large valve engine and large carburetter we obtained 6%. The 116° camshaft raises the R.P.M. at which the power peak occurs by 5½% but when used in conjunction with larger valves and carburetter the peak is raised by 12.3%. The Std. crankshaft has the advantage at low speeds. This is better shewn by referring to the B.M.E.P. curves where we see the advantage is to the extent of 8.3% at 1000 R.P.M. Actually this gain in M.E.P. at low speeds is quite appreciable on the road, whereas it is necessary to have a substantial increase at high speeds to appreciate | ||