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).
Horsepower tests and carburetion improvements for the Goshawk I engine.
| Identifier | ExFiles\Box 50\3\ Scan088 | |
| Date | 1st May 1921 | |
| To R. {Sir Henry Royce} From Hg. c. to OJ. c. to EN. c. to E. {Mr Elliott - Chief Engineer} c. to D. {John DeLooze - Company Secretary} c. to BY. {R.W. Bailey - Chief Engineer} X4305 Hel/LGS1.5.21. X.3481 X.1692 RE. GOSHAWKAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine 1. X.4305. Attached herewith is a Curve showing the latest horse power taken on GoshawkAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine 1 both on the Test Bench and Dynamometer. On this curve we also give a comparison of the M.E.P. obtained on the GoshawkAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine, Marmon and 40/50 chassis. We have compared it with the Marmon car because this car has given the best M.E.P. of any car we have tested so far. We have greatly improved the carburation on the little GoshawkAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine. We have made up a R-R Carburetter with a butterfly valve and smaller air valve. We have made a new induction pipe using a pipe 1.5" diameter instead of 1.625" as we have used before. We have arranged a real effective hot-spot close up to the carburetter. We can appreciate on this engine a very great improvement with the hot-spot in operation. It is possible to maintain a steady and even torque at 300 R.P.M. full throttle. Improving the carburation has made a great difference to the car on the road. On hills which it would not climb on top gear, it now climbs easily. The improvement in torque at low speeds, however, has made the pulsations of the engine very much more manifest. Previously, if the throttle was open fully at low speeds, the engine felt smooth and the picking-up was without much vibration, now, however, the vibration is quite marked. contd:- | ||