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 tests investigating chain rattle, oscillation, and cylinder head water leaks.
| Identifier | ExFiles\Box 113\5\ scan0178 | |
| Date | 5th December 1936 | |
| Test No.10. Second tensioner fitted to driving side of chain; otherwise as test No.9. Result. A slight rattle can be heard at 1000 R.P.M., but above this speed, although occasional vibrations can be seen in the movement of the chain, no other noise can be heard. Test No.11. Engine returned to original specification of test No.1. With the second tensioner added on the driving side, and the flywheel fitted to the camshaft. This second tensioner is rigged up, so as to give the same load as the original tensioner on the slack side of the chain. Each tensioner gives a pressure load of 10 lbs on each side of the chain. Result. Only one period can be heard; that being at 1000 R.P.M. No other noise from the chain can be heard from the rear of the engine. If the flywheel is removed from the camshaft, the period at 2,000 R.P.M. is almost as bad as it was in test No.1. without the second tensioner however, the flywheel only accounts for 50% suppression of the 2,000 R.P.M. period. It is seen, therefore, that only when applied in conjunction with one another are the second tensioner and camshaft flywheel successful. No means have so far been devised for dealing with the oscillation period at 1000 R.P.M. an experimental cam balancer is being fitted however, with which it is hoped to be able to damp out this period. It will definitely be necessary to do something about this low speed oscillation, as the noise is considerably louder than the engine gear rattle associated with most production engines. Cylinder head water leaks. The fitting of a "Corrujoint" gasket only partially cures the water leak on the induction side of the engine. We would stress the remarks of our previous report re narrow bedding surfaces, as there is no gasket material available which could make this idea a complete success. We do not consider, therefore, that another row of studs will eliminate a grave risk of internal water leaks. | ||