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 responding to a query about the horsepower required to circulate engine oil.
| Identifier | ExFiles\Box 136\3\ scan0082 | |
| Date | 24th July 1940 | |
| 1139 24.7.40. Rm.{William Robotham - Chief Engineer}12/JMS. The Harboro' Aircraft Manufacturing Co.Ltd., Market Harborough, Leicester. For the attention of Mr. Worth. Dear Sirs, With reference to your query with regard to the horse power required to circulate oil. You are quite correct in saying that the theoretical horse power to circulate 3 gallons of oil a minute at 50 lbs per sq.in pressure is one tenth of a horse power. In practice, the measured horse power required to drive an oil pump is nearer three. This seems to be ridiculous but, at the moment, I cannot check it owing to pressure of other work. I send you herewith two photographs of bearings run with and without filters. I have no results that can be incorporated in a report on our continental test because the car is still running, and we have not had an opportunity to pull it down. Please return the photographs when you have reproduced them. Yours faithfully, | ||