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).
Outlining two methods for designing a high-altitude engine, including a proposed safety device.
| Identifier | Morton\M8\ img020 | |
| Date | 4th June 1917 | |
| 6 To S. from R.{Sir Henry Royce} c. to Na.{Mr Nadin} c. to EPC. ORIGINAL. R3/B2:6:17. RECEIVED 4 JUIN 1917 X 3065 Re. Engine for High Altitude. Regarding the engine to the Admiralty specification of not requiring the engine to do any greater horse power with full barometer than it is capable of doing with 10.5 lbs. atmospheric pressure, there are two distinct ways of attacking the problem of a light engine at 10,000 ft. One way is to build the cylinders large and light, with an ordinary compression ratio of say 5 to 1, and be satisfied with a maximum and mean pressure much lower than is obtained with an ordinary engine at full barometer pressure. X 3026 This seems to be the better method at the moment, but the other means would be to make an engine to work with the full barometer pressure at sea level, and maintain that barometer pressure at an altitude of 10,000 ft. by compressing the air from 10.5 to 15 lbs., and letting the engine draw from a reservoir filled with air at such a pressure. Both schemes could have the following safety device applied to them, which I think may be found to be novel. In the case of scheme I, the engine would never be allowed to draw its charge from air at atmospheric pressure, otherwise the maximum pressure in the cylinder will be so great as to do some damage. To prevent this, I have proposed the following scheme:- That the suction of the engine is taken from a reservoir of very small capacity, probably a pipe the size of the induction (Contd.) | ||