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).
Technical analysis of the claimed advantages of the Aspin engine, including compression ratios and spark plug life.
| Identifier | ExFiles\Box 144\4\ scan0086 | |
| Date | 1st May 1940 | |
| Cont'd.{John DeLooze - Company Secretary} RM.{William Robotham - Chief Engineer}1/HL.1.5.40. valve engine fails it is likely to wreck the engine, particularly in the case of the latter. This should not occur in a correctly designed aspin engine. DESIRABLE ADVANTAGES OF THE ASPIN ENGINE. The following advantages are claimed for the aspin engine but obviously require substantiation, under more accurately determinable conditions. 1. Ability to run at higher compression ratios than have hitherto been possible on internal combustion engines. We have taken aspin's figures and accepted the octane value which he gave us for the fuel. The results indicate that his engine can operate at something like 15 - 20 M.E.P. higher than our own on a given fuel at low speeds. This might be stated as being the difference between 5½/1 and 6/1 c/r.{Sir Henry Royce} 2. Better Spark Plug Life. The spark plug is alleged to run cooler and in consequence have a longer life since it is separated from the combustion for a considerable percentage of the firing stroke. On the other hand, when the temperatures are highest the plug has got to be in contact with the products of combustion. In connection with the capacity of the aspin engine run on a higher c/r, there is no doubt that aspin's combustion chamber can be reproduced on a single sleeve valve engine. However, the mixing of the charge in the way in which it is introduced into the chamber may also have some bearing on the detonation. - continued - | ||