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).
Comparative report on the performance of car models 21-G-IV and 22-G-V.
| Identifier | ExFiles\Box 123\4\ scan0269 | |
| Date | 15th July 1936 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to GWH.{George W. Hancock - Head Chateauroux} X 1042 Hs{Lord Ernest Hives - Chair}/IMW.{Ivan M. Waller - Head of Chateauroux}3/KW.15.7.36. Comparison of 21-G-IV with 22-G-V.{VIENNA} I have tried 21-G-IV as instructed, and have observed the following points of comparison. Engine. There is no noticeable difference between the two cars for power and acceleration. There is bad misfiring cold and slight misfiring hot on pick up from 10 M.P.H. exactly like that which we overcame on 22-G-V by fitting the new distributor with larger flashover distances. 21-G-IV is fitted with the standard distributor, and when the misfires occurred sparking was audible. The engine responds very much more readily to sudden depression of the accelerator and the impression of leanness with which we are trouble on 22-G-V is completely absent on 21-G-IV, and we shall therefore renew our efforts to get to the root of this fault. Tick over is better on 21-G-IV but the compressions are all good, whereas they are bad on two cylinders and generally uneven on 22-G-V, so it is difficult to draw a fair comparison on slow running. The engine of 21-G-IV is timed approximately 14° early and is practically free from detonation. 22-G-V is equally as good in this respect when timed 14° early with either cylinder head. Examination to see if our trouble with loose fan blade rivets was reproduced revealed that 21-G-IV is fitted with what appears to be a Bentley fan. Gearbox. The third gear synchromesh is better on 22-G-V, the gears are otherwise similar. Brakes. The slight servo judders experienced on 22-G-V are very much more pronounced on 21-G-IV. Braking is otherwise similar. | ||