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).
Goshawk 11 engine's torque curve and hill climbing performance.
| Identifier | ExFiles\Box 74\4\ scan0173 | |
| Date | 20th May 1922 | |
| X4134 To Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} GOSHAWK 11. PERFORMANCE X.4134 In reply to your Hsl/LG17.5.22., we would refer you to our memo. to Mr. Royce El/M8.4.22 - (copy to yourself) and sheet of HP. and MEP. curves - LeC.1548. As you know the only thing that matters for a top gear hill climbing performance is torque. If you have a car with an absolutely level straight line torque curve which did not fall at all, this would be a very disappointing car. We are approaching this on the Goshawk. It is a great merit that the torque falls so little with increase in speed, but it means that the performance at high speed is so good as to make the performance at low speed relatively poor. If you will look at the MEP. or torque curves on LeC. 1548 you will notice that for the same range of speed the Goshawk MEP. only rises about 9 lbs. when slowing up as compared with 20 to 30 lbs. on the other cars curves. This means that you have nothing in the way of torque to get your back up against for getting away again. The proper way to drive the car of course for a good performance would be to change down long before the speed of the engine had dropped, but this is not customary. We can only suggest that we should endeavour to raise the MEP. at slow speed still higher as suggested in the previous memo. mentioned, even at the expense of the performance higher up. Also that relative figures could be got out on the basis of capacity per ton mile, and relative performances could be obtained between the 40/50 and Goshawk 11. on any given hill with pro rata loading. E.{Mr Elliott - Chief Engineer} | ||