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).
Piston failure, design choices, and market conditions in America.
| Identifier | ExFiles\Box 170\2\ img176 | |
| Date | 30th November 1933 guessed | |
| -2- The piston we are sending you failed through a valve head coming off and hitting the crown, but it should be good enough to show you what bedding they obtain, and also the dimensions of the piston. Naturally we are not going over to this unsplit type of piston in a hurry, as you can imagine. By the time I see you we should know a bit more about their freedom from knocking under ordinary car users conditions. Actually for a high output engine, such as you are able to use in America owing to absence of H.P. tax and low prices of petrol, there should be no difficulty in making a split skirt stand up to the job. Taking it alround, our standard split skirt job is wonderfully free from trouble, and up to 3 3/4" bore, and even on the 4 1/4" Phantom, piston knocks are now a rarity. We are in entire agreement with you with regard to the 12-cyl. Cadillac and the Bentley, and were going to suggest the same ourselves. The difficulty is purely a matter of getting our directors to see eye-to-eye with us on the subject. Kind regards to Mrs. Olley, Yours sincerely, | ||