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).
Camshaft tests for the Peregrine engine, analyzing M.E.P. and power results from different configurations.
| Identifier | ExFiles\Box 1\10\ B001_X106 TO X 110-page038 | |
| Date | 12th July 1932 | |
| E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} X107 Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}7/MA.12.7.32. PEREGRINE CAMSHAFT. We fitted up a Peregrine head with exhaust valves in the inlet position to see if this would improve the low speed M.E.P. Curve Rn.{Mr Robinson}P.15 indicates the results. The top power suffers from the fact that long reach plugs were not used. We think the gain in M.E.P. over the normal running range is worth more than the small loss in top H.P. to the average owner. Curve Rn.{Mr Robinson}PR.16. Was a camshaft made of two inlet cam forms to reduce the duration of the exhaust valve opening. This enabled us to use an early closing inlet valve without the exhaust valve opening too early and a moderate amount of over-lap. It will be noted that a very definite improvement in low speed M.E.P. can be obtained when the toe of the cam is eliminated by increased tappet clearances, but the top power is reduced. Curve Rn.{Mr Robinson}PR.17. Is a repetition of the same tests on the same camshaft but with a later timing. With .020" tappet clearance this seems a good compromise. Curve Rn.{Mr Robinson}Pr.18 shews the best results with the two best camshafts and timings tried. Camshaft (2) has too much over-lap for slow running we find, otherwise it would be the better of the two. We find that about 30° over-lap is as far as we can go on this head if we are to run evenly at 250 R.P.M. | ||