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 development strategies in relation to different fuel octane ratings and specifications.
| Identifier | ExFiles\Box 27a\4\ Scan204 | |
| Date | 4th September 1933 guessed | |
| (2) (4) It is for each engine constructor, then, to review the position of his engines in active development but not yet in Service production, and to submit his proposals to the Department as to the further lines of development of each individual type. (5) The offer of increased performance latent in the new fuel cannot be accepted at the expense of serviceability and overhaul life. It may therefore be expedient, during the next few months, in the first place to establish a new mark or type of engine on the 77 octane D.T.D.224 fuel while orderly and thorough development proceeds with the next "mark" engine to take the eminently desirable advantage of an 87 octane rating, as soon as is practically justifiable. (6) Where, however, the design of the new engine as a whole has been deliberately detailed in anticipation of the additional stresses of the higher output obtainable, and furthermore, there is reliable evidence to indicate that valves, valve seats, spark-ing plugs, etc., in a particular design will withstand T.E.L. effects, the intermediate step would be redun-dant and effort should be concentrated wholly on the 87 D.T.D. 230 basis, that fuel becoming progressively the main supply to the Royal Air Force until a yet further step, on similar lines, becomes practicable. (7) For General Service purposes no consideration can be given to engine projects concerning fuels of quality intermediate between the two new specifications. (8) For purposes of engine type test, the fuel used must not exceed the specification values of 77 and 87 octane number respectively, by more than one unit as a tolerance. (9) Whereas D.T.D.230 prescribes a maximum limit of 4 ml. T.E.L. content per gallon it is probable that the fuel delivered in bulk to the Royal Air Force by the various suppliers will normally require a smaller quantity of T.E.L. Cont'd.{John DeLooze - Company Secretary} | ||