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).
Engine harshness from slipper wheels, compression ratios, and the work status of experimental cars 1.EX and 49-GB.
| Identifier | Morton\M11\ img214 | |
| Date | 17th September 1919 | |
| Contd. -2- with only half the usual number of springs on the slipper wheel. The Test Dept: also have stated that tight slipper wheels caused the engine to be harsh - they always see that the slipper wheel can be moved under a certain load. Our idea was that if reducing the friction on the slipper wheels on 1.EX brought on no other trouble, we should recommend it for standardisation. As regards compression ratio, the compression on 1.EX and 49-GB is the same. The compression ratios on Production Cars have come out lower than we first intended. It was agreed that the cubic capacity of the combustion chambers should be 22.5 ins. high compression and 25 ins. low compression. Actually, the cars are 23.5 to 24 ins. 26 to 26.5 cu.ins. Both 49-GB and 1.EX have 23.5 cu.ins. capacity. 7-CA Car was running with 22.5 cu. ins. It has been agreed at the Works that to keep the compression low is a desirable thing and we do not propose carrying any alteration to existing cars in this respect. As regards changing 49-GB. We have no other car at the Works fit to send. 1.EX, the body is being taken off so that Messrs. Holmes can complete their work on it. We are completing the Car as regards Wiring and fitted Disc Wheels. This car in its complete state will be ready to be sent to Mr. Royce at the end of this month. If it is at all possible, we would recommend that 1.EX is properly finished and then sent down to replace 49-GB. EH. | ||