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).
Aero engine reliability, focusing on piston failure from oil gumming and comparing various oils.
| Identifier | ExFiles\Box 43\3\ Scan132 | |
| Date | 1st March 1927 | |
| 2862 K4003 To RG.{Mr Rowledge} Hs.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} from R.{Sir Henry Royce} c. to BJ. Wor.{Arthur Wormald - General Works Manager} HY.{Tom Haldenby - Plant Engineer} ROLLS-ROYCE LIMITED DERBY AERO ENGINE RELIABILITY. X.3804 X.1282 X.4003 X.3996 I am very anxious about the above, and all our talent should be concentrated on this feature before we think about anything else, including gears and supercharger. It seems we must have our 2 engines - F.10. and H.1. reliable as an engine - (1) direct drive. (2) carburetters in Vee. (3) light weight. then we must have gears, and then supercharger. We seem to be short of reliability because of piston failure from 2 causes - (a) gumming up, resulting in piston failure, and (b) failure of piston pin boss or pin. Regarding (a) I cannot think all our designs are so imperfect as to cause gumming up, and we ought to settle definitely if it is a question of oil; as far as I remember this has not been done, in spite of our several suggestions that this was the most likely cause, and I have written on the subject long ago that I should expect the order of gumming as follows - (i) Untreated castor. (ii) Treated castor (Wakefields) (iii) Price's compound. (VI) Wakefield's compound - recommended for cars. (V) Good quality of straight mineral, such as Vacuum. One would expect Wakefield's or Price's would be able to help us and give us some oil that would at least shew a difference. I have got an impression that the Expl: Dept: say there is no difference in all these oils, so widely different in character. If however we have come to a deadlock we should go to Mr. Ricardo for help, but I think we should be in as good a position as he to shew whether it is matter of oil. The second cause - i.e. mechanical weakness, has I believe been overcome in the later Y. metal piston. My impression is that any piston will fail after the rings are gummed up. RG.{Mr Rowledge} should make this item his first thought | ||