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).
Modifications for a competition cylinder head for E.R. Hall's car.
| Identifier | ExFiles\Box 90a\2\ Scan289 | |
| Date | 4th December 1934 | |
| To RHC.{R. H. Coverley - Production Engineer} 47962 Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}2/KW.4.12.34. Competition Head - E.R. Hall's Car. As a result of single cylinder running, certain modifications are recommended to the high compression heads we are producing for competition work. The attached sketch V.1732 shows the suggested departures from the drawing EX.16041. One head is almost completed and we should like to run this as it is before we make any modifications, we should like you, however, to machine the second head to V.1732. The main modifications to this are :- (1) 1.350 diameter exhaust valve. (2) Increased lip to give more forced turbulence. (3) Inlet port opened out and valve guide boss removed. When we get these heads having larger volumetric efficiency we anticipate that we shall get a restriction from the 1.375 diameters of our induction pipes. Will you therefore please prepare an induction pipe having 1.5 diameter bore throughout. We think that this could be machined from the existing standard pipe. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||