Engine bore and stroke for the 20/25 model, advocating for a larger bore to increase performance.
| Identifier | ExFiles\Box 5a\1\ 01-page179 | |
| Date | 14th July 1931 | |
| To E. {Mr Elliott - Chief Engineer} from HY. {Tom Haldenby - Plant Engineer} re Japan(Experimental Engine) III. Sg {Arthur F. Sidgreaves - MD} 11/M14.7.31 Copy to Hs. {Lord Ernest Hives - Chair} Lr. {Mr Ellor} 20/25. E. {Mr Elliott - Chief Engineer} De. Sy. HS {Lord Ernest Hives - Chair} 85770 Referring to your recent memo. wherein you again refer to the question of retaining the 3.25 bore for the 20/25 but increasing the stroke to 5", I have been thinking this matter over and I feel that the right thing to do is to adhere to the compromise which we arrived at in January last which was for a bore of 3.4. Personally I cannot see how we are going to obtain satisfactorily an increased performance unless we have this small increase in the bore. We have to remember that the majority of our purchasers place comfort and silence first and I do not feel that it will be satisfactory to rely on obtaining the increased performance we look for by expedients such as increased compression ratio, twin carburettors, etc. as in so doing it seems to me that we are more or less bound to increase the fuss and noise element. I do not think that the private venture engine to which you refer should be allowed to influence the decision in any way whatsoever. Sg. {Arthur F. Sidgreaves - MD} | ||
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).