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).
Test report on American valve springs, maximum speed limitations due to the exhaust system, and issues with squeaking brakes.
| Identifier | ExFiles\Box 11\3\ 03-page168 | |
| Date | 7th July 1930 | |
| To: Hs.{Lord Ernest Hives - Chair} From G.W.H. X77)3. Hôtel de France, Chateauroux, Indre. 7/7/30. We resumed running yesterday afternoon after attention to the exhaust valves. As stated, we fitted the American valve springs, these were thoroughly tested out during the afternoon and I find that they are superior in every way to our own valve springs. Although the valve springs were a very loose fit on the spigots of the top and bottom washers, there is no audible sign of any swishing. The engine ran very smooth with no noise from the valves. They appear also to have an effect upon the engine gears, which is logical, as, being more free from any periods, there is no reaction taking place to the camshaft. Acceleration on 3rd. gear is equal to our valve springs, 68 M.P.H. being reached with good acceleration the whole way. No sign of any valve bounce took place. We are candidly very pleased with them. Re maximum speed of car. We have got ample evidence that the maximum speed of the car is being held down by the exhaust system. We have almost at the present moment got an open exhaust due to the failure of the aluminium front expansion chamber. Our maximum speed reached, during the run last evening was 82 M.P.H. Would it not therefore be to our advantage if the larger intermediate pipe was sent out? The brake squeaks on this car are a disgrace to any Rolls-Royce car, and we do not think it advisable to continue running with the Mintex brake shoes. Anyone seeing the car and hearing the results of a slight application of the brakes would immediately form a very bad opinion of the R.R. car. We have had a go at quietening them by bedding, | ||