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).
Customer feedback on a car, covering issues with the carburettor air valve, piston sticking, fuel consumption, and exhaust explosions.
| Identifier | ExFiles\Box 47\1\ Scan206 | |
| Date | 7th December 1925 | |
| COPY OF MEMORANDUM No. 8839. REFERENCE St3/IN/7.12.25. Re Geoffrey Summers, Esq. Chassis No. 117-MC. Comp. delivery, 21.8.25. The owner is very pleased with the car. In considering his criticisms it is necessary to bear in mind that he is an enthusiastic motorist and a confirmed speed merchant. His chief criticism concerned the carburetter air valve and the exhaust throttle. With regard to the air valve he suffered continual trouble owing to the sticking of the pistons. Repeated polishing with metal polish failed to cure the trouble. He then tried the use of fine emery paper and finally put it in a lathe and slightly reduced it. He maintains that, owing to the proximity of the exhaust pipe and the expansion of the aluminium piston, the sticking is bound to take place under continuous fast running conditions. Except when thoroughly hot the piston is now too free, and although he is unable to notice any effect upon the engine's performance, he thinks that the efficiency of the valve as-it-is is impaired and that it does not lift to the same extent as it did when it was close fitting. I did not see the car as the owner had had to leave it behind him in the Lake District on account of the icy and slippery state of the roads. The car is run upon 75% No. 1 petrol and 25% benzol. Petrol consumption gives 12/13 m.p.g. as compared with the 16/17 m.p.g. that he obtained with his former R.R. car. I understand that both cars are fitted with 16 x 52 axles. The owner no doubt takes advantage of all the acceleration obtainable, and I pointed out the fact that more can be obtained from the Phantom would largely contribute to this result. On the other hand, he said that on his recent run to the Lakes, when owing to slippery roads he averaged less than 30 m.p.h., petrol consumption gave nearly 14 m.p.g. Another factor which no doubt affects the case is the weight of the two cars; 117-MC is said to weigh 44 cwt., while 39-TW which was fitted with an exceptionally light body, was no doubt a good deal less. The owner complained that this car suffers a good deal more from explosions in the exhaust when descending hills than did his former car. | ||