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).
Performance comparison between the Goshawk and 40/50 models based on weight, engine displacement, and gear ratios.
| Identifier | WestWitteringFiles\J\November1922\ Scan98 | |
| Date | 19th July 1917 | |
| R.R. 199 (250T) (SD676 19-7-17) MP180865 contd:- -2- It will be seen that based on displacement per ton per mile the Goshawk is considerably more heavily loaded than the 40/50. It is only the increased engine efficiency on the Goshawk compared with the 40/50 that enables it to perform as it does with the load. Car. Guaranteed weight. Displacement of engine. cu.ins. Direct gear ratio. Low gear in each case. Displacement per ton per mile. 40/50 55 cwts. 453.3 26 m.p.h. at 1000 r.p.m. 14 X 52 190060 cu.ins. Goshawk. 39 cwts. 190.8 20.5 m.p.h. at 1000 r.p.m. 13 X 60 143180 cu.ins. Present guaranteed weight of G.11. = 39 cwts. Required weight to equal 40/50 in displacement is = 29.38 cwts. or 3290 lbs. Hs.{Lord Ernest Hives - Chair} | ||