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 performance comparing different camshafts, compression ratios, and ignition settings.
| Identifier | ExFiles\Box 5a\5\ 05-page114 | |
| Date | 26th April 1934 | |
| -2- (with 5.75 C.R.) shows a marked increase in power over the standard engine at speeds above 3200 R.P.M. From the point of view of detonations, the 112° shaft in the 5.75 C.R. engine is noticeably worse than standard; but if the ignition is slightly retarded, so as to effect a drop in power of not more than 3%, this engine becomes slightly better than standard in this respect. The ignition setting for these conditions is 10° before T.D.C. when the hand control is in the fully advanced position. It is suggested that an engine similar to the above should be tried in a car, as the increase B.H.P. above 3000 R.P.M. should noticeably improve the acceleration at that point. The 116° camshaft (having the same long duration cam as the 112° shaft) has been tested on the 5.75 compression ratio engine; a power curve of which will also be found on V.501. The effect of testing these camshafts with the same compression ratio is indicated on curve V.751. He/HP. | ||