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).
Feasibility and design considerations for fitting a Phantom II with a 6:1 compression ratio cylinder head.
| Identifier | ExFiles\Box 65a\3\ scan0299 | |
| Date | 1st June 1931 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. SS.{S. Smith} c. WGT. E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Ev.{Ivan Evernden - coachwork} 17770 Hs{Lord Ernest Hives - Chair}2/AM1.6.31. 17771 PHANTOM II. 6 : 1 COMPRESSION RATIO. In a recent memo you asked for P.2. to be fitted up with 6 : 1 compression ratio. We have no cylinder head which will give us this ratio. We have modified the present one so that we can obtain 5 : 1 instead of the standard 4.6, but to make it suitable for 6 : 1 we think the design should be gone into. We are certain that we shall never be able to use a 6 : 1 compression ratio on a car which we could sell to a customer. It would only be useful purely as a car to run on the track with special fuel. In our opinion a compression ratio of about 5 1/2 : 1 is about as high as we can go on the P.2. If you wish us to carry on with 6 : 1 ratio we should like a scheme showing how it should be arranged. Hs.{Lord Ernest Hives - Chair} | ||