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).
Investigation into an improved power rating for the Goshawk engine, comparing different fuel types and their performance characteristics.
| Identifier | ExFiles\Box 27a\4\ Scan212 | |
| Date | 14th September 1933 | |
| -4- Ha/Yms.2/H.J.14.9.33. Cont'd.{John DeLooze - Company Secretary} value of the fuel may be obtained by reference to Curve 443 F.{Mr Friese} (b) Investigation of an improved rating for the Goshawk. The power obtained at 2600 R.P.M. and +4lbs/sq.in. boost proved to be 684 BHP., 9/10ths. of this (615 BHP) was obtained with +3lbs/sq.in. boost whilst the safe limit was reached at 4 lbs/sq.in. at 660 RPM. The margin of 1 lb/sq.in. was considered to be insufficient, detonation troubles being anticipated at 9/10ths. C.L.P. when the 10.06/1 supercharger gears were fitted. As explained previously, a rating was consequently established at increased speed (See curve 444F.). 700 BHP/2900 RPM./+3lbs/sq.in. boost at 11,500 ft. C.L.P. 625. Max. Perm. M.S.L. 3535. In addition a full set of power consumption curves were taken at this rating. From these it will be seen that the low calorific value of the fuel together with the impaired blower efficiency are reflected in the consumption figures. A check at 9/10ths. on level power showed the rating to be just possible - i.e. running at this power and C.L.P. fuel consumption the detonation intensity was 1 to 2 ft., this being considered to be the maximum allowable at normal speed of 2900 R.P.M. the CONCLUSIONS. D.T.D.224. This fuel offers only a very slight improvement over D.T.D.134 from the standpoint of detonation and is a little inferior in calorific value on a volume basis. Contrary to our original assumptions - report ref: Ha/Yms.4/WJ.30.8.33 - this fuel is not D.T.D.134 loaded up with benzol but a straight petrol naturally high in aromatics, probably a Borneo grade. D.T.D.230. (1) The Fuel. This is a straight grade petrol probably of Californian origin loaded up with T.E.L. to bring the octane number up to the specified figure. It is a vast improvement on D.T.D.134 as regards detonation but is naturally of considerably lower calorific value per unit volume - assuming DTD.134 to be 141,200 BTU/Gall. then DTD.230 is 136,500 BTU/Gall. | ||