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).
Letter to Ethyl Export Corporation regarding permissible M.E.P. results for a Kestrel S. engine with different octane fuels.
| Identifier | ExFiles\Box 27a\4\ Scan228 | |
| Date | 20th September 1933 | |
| 81282 Expl. Dept. Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey}1/MJ. 20th. September 1933. F.R.Banks Esq., Ethyl Export Corporation, Abford House, Victoria, LONDON.S.W.1. Dear Banks, In reply to your letters of the 4th. and 7th. inst., we have looked up some of our results on the permissible M.E.P. for octane value and while the results are only approximate they may be suitable for your purpose. The standard Kestrel S. will operate without trouble from destructive detonation at approximately 146 B.M.E.P. This is under conditions of over boost for take off and on D.T.D.134 or 76 octane. With the 90 octane fuel - or the D.T.D.134 plus 4 cc's. it will give 195 B.M.E.P. at normal revs. As an intermediate point we have run at at 181 B.M.E.P. on Welbeck fuel which was stated to have a value of 85 octane. We have filled in a curve on the graph you sent and consider this represents approximately a safe operating M.E.P. for the octane values given. With regard to the other question I do not know whether you are thinking in terms of gas velocity or merely valve size. Anyhow you will be able to obtain which you require from the following figures :- Cont'd....... | ||