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).
Speed test of the 4-Goshawk-11 at Brooklands, diagnosing and fixing a pre-ignition issue.
| Identifier | ExFiles\Box 29\3\ Scan114 | |
| Date | 1st August 1922 | |
| C O P Y. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} Hs{Lord Ernest Hives - Chair}1/LG18. 8.22. RE. GOSHAWK 11. - SPEED. X.788. On my way to London I called at Brooklands with 4-Goshawk-11. On the track we proved that the reason of the drop in speed of 4-Goshawk-11 was due to pre-ignition. The car, as it was, would not go above 50 m.p.h. There was no popping and none of the obvious signs of pre-ignition, but there was no doubt that it was pre-igniting. After changing the plugs for another type, the average speed for a lap was 59 m.p.h. (with the silencer fitted) - with a free exhaust, the average speed was 63.0 m.p.h. for a lap. The maximum speed over the half mile was 68 m.p.h. The engine ran remarkably smoothly - even at the highest speeds it was difficult to pick out any marker vibration. The acceleration with free exhaust - 10 to 60 m.p.h. 43 1/4 secs. - 10 to 50 m.p.h. 29 We think this is a very creditable performance. The effect of the wind was very marked - on some portions of the track with the wind against the car, it was difficult to reach 57 m.p.h. - with the wind favourable, the speed was nearly 70 m.p.h. Hs.{Lord Ernest Hives - Chair} | ||