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).
Design work, challenges, and questions regarding the Aspin engine.
| Identifier | ExFiles\Box 134\1\ scan0233 | |
| Date | 17th May 1940 | |
| C.T.C 1129 Please discuss with me Rms To Rm.{William Robotham - Chief Engineer} Lnr.10/JH.17.5.40. File ASPIN ENGINE. The design work that Fletcher has done on the aero side is interesting. He has plotted a diagram for the inlet valve opening and it shows that the Aspin valve compares unfavourably with the sleeve valve and poppet valve. Another drawing shows the difficulties he has encountered in getting 2 sparking plugs per cylinder. It has forced him to put the plugs in deep pockets. He is in trouble with frontal aspect, which of course only applies to an aero engine. His idea is to drive each Aspin valve by a worm and wheel so as to avoid back lash and time-lag between cylinder numbers 1 and 6. The worm and worm wheel drive introduces a thrust upwards or downwards on the Aspin valve which has to be catered for by the bearings in addition to the explosion load. .......... It would not be fair to put a severe questionnaire to Mr. Aspin as I understand he is not technically advanced. (MATRIC ?) However, here are some points for discussion next Wednesday. (1) We should like the recommended timing diagram. (2) Will the engine run naturally aspirated since it appears that the incoming charge is opposed by the centrifugal force of the rotating valve. (3) What boost pressures have been used. (4) Is there not vertical blow by, which escapes into the rocker cover via the bearings. Cont'd.{John DeLooze - Company Secretary} | ||