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).
New high-power cylinder head for a Bentley race engine to resolve pre-ignition problems.
| Identifier | ExFiles\Box 90a\3\ Scan077 | |
| Date | 13th June 1935 | |
| To RHC.{R. H. Coverley - Production Engineer} 4262 Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation}3/KW.13.6.35. High Power Head - Bentley. Further to our memo. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}5/KW.12.6.35, when B-4 Unit is sent into the shop, will you also on reassembly fit new con rod bolts and inspect spring drive and slipper wheel, etc., which rattles very badly. A new cylinder head will be required for fitting to the final unit to compete in the race; for the following reason. The head we have available at the moment has a capacity of 65 c.c's, and when using the correct gasket for this sort of work, the compression ratio is too high for use with the fuel that is limited to the T.T. If extra gaskets are used to lower the ratio, we run into trouble from pre-ignition. The head required is as follows, for which you may already have a spare casting :- EX.17749 Cylinder Head. EX.17456 Inlet Valve. EX.15604 Exhaust Machine face to give final capacity of 75 c.c's. Hs{Lord Ernest Hives - Chair}/C.T.Salt. | ||