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).
Engine design, including centrifugal blowers and crankshaft drive options, with comparisons to Bentley and Leyland engines.
| Identifier | ExFiles\Box 140\3\ scan0237 | |
| Date | 17th February 1939 | |
| -2- Rm{William Robotham - Chief Engineer}3/R.17.2.39. which has just been completed in the D.O. We should, if possible, make provision for a centrifugal blower, which we fitted on the Bentley some 3/4 years ago. This was exceedingly simple, and would enable us to get another 15 M.E.P., in any case where exceptional output is required. Naturally, the centrifugal blower is, more or less, a constant speed boost device, but on a boat maximum power is only required at a more or less constant speed. Incidentally, as a matter of interest, Leylands say they have had the General Motors two-stroke on test, and, apart from a piston failure, they were disappointed with its power output, and said their operators would not tolerate a specific consumption as high as they measured on this engine. One rather interesting piece of information we got from Leylands was that the chain drive on the front end of the crankshaft has a life of something over 100,000 miles. In view of the fact that for their engine size they have a relatively flexible crankshaft, and that the maximum pressure on a diesel is almost certainly 25% higher than that of a petrol engine, it is curious that we should have to use a spring drive with gears while Leylands get away with a chain. For this reason, we think we should at least try the chain drive which was designed as an alternative on the Convention-al engine before we finally commit ourselves to the complica-tion of a spring drive. We should be glad if the necessary details for producing the chain could be issued forthwith. Rm.{William Robotham - Chief Engineer} | ||