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).
Conclusion of tests on high lift rockers and 'R' type camshafts, including results from Test No.3.
| Identifier | ExFiles\Box 82\4\ scan0386 | |
| Date | 1st October 1936 | |
| -9- Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation}16/KW.1.10.36. Test No.3. Details of test as in Test No.2, with camshaft as follows - Increased duration of both inlet and exhaust cams, by opening the inlet valve earlier and closing the exhaust valve later. Apart from showing approx. the same power at 4500 R.P.M. as the standard shaft, a loss is shown at all other speeds. CONCLUSION. A few more parts were tested in conjunction with this programme, and should be mentioned. Reliable figures of merit cannot be given, however, as the tests were carried out on the first cylinder head mentioned in this report, and became confused with the overheating troubles mentioned in Part I. (1) High lift rockers, giving .050" increased valve lift in conjunction with an 'R' type camshaft, Hs.{Lord Ernest Hives - Chair}965. (2) High lift rockers with standard camshaft. (3) 'R' type camshaft with standard rockers. It can safely be said, however, that any small gain which might have been forthcoming from any of these arrangements would not have warranted their inclusion in the final specification of the engine. In the case of the high lift rockers, for instance, a lot of trouble was experienced in splitting top valve spring washers, due to running the valve springs too near choc-a-bloc. With the 'R' type camshaft, or any of the special camshafts, the use of plain cam followers would have brought in an element of risk, compared with the standard roller type. | ||