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).
Committee report discussing valve spring breakages, proposing rig tests, and addressing related technical queries.
| Identifier | ExFiles\Box 80\3\ scan0096 | |
| Date | 4th October 1911 | |
| (2) it advisable to make further investigations concerning the possibility of still further reducing this stress, and as previously recorded in the minutes, have ordered 1 gross of special springs designed on these lines. They proposed to run a test by a special rig which will be equivalent to 10,000 miles on the road. The Committee recommend that owing to the more frequent occurence of spring breakages, that the whole of the springs at present fitted to engines having the new camshaft, should be replaced by these modified springs if they prove satisfactory by the above tests Mr Platford pointed out that the valve springs fitted to the engine with the first of the new type of camshaft had never failed. They had been running continuously ever since the car was built, and had been in use on the demonstration car for a considerable period. The total number of miles run was about 15000.. Mr Johnson asks :- 1. Why the springs broke? 2. Information concerning the tests of this chassis.? 3. Why the rotor gave trouble? 4. Whether valve springs are likely to give trouble on other cars. ? The Committee's replies to these questions are :- 1. The breakages are probably due to the increased lift on the new camshaft. 2. Mr Platford reports that the valve springs gave no trouble on this car during test, and added that he never [Faint upside-down text at bottom] R.R. 335A (100M) (W) (HOOH) 955 (4.10.11) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2053 | ||