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 tests conducted with air boxes and modified camshafts, including a comparison table of results.
| Identifier | ExFiles\Box 43\3\ Scan184 | |
| Date | 17th September 1928 | |
| contd :- -2- (2) The engine was sent back to the Works and a further test was conducted with air boxes (17.9.28). The results are shewn on Sheets 1. and 2. dotted lines. There appears to be a gain in B.HP: compared with the original tests. Unfortunately, the engine was not tested as delivered from the aircraft, as due to a misunderstanding, the camshaft was stripped but afterwards put back and re-timed. The increase in power between tests 1. and 2. may be partly due to the engine having run itself in during the flying time with a possible benefit from a slightly changed timing. (3) Modified camshafts fitted and tests conducted with exhaust gases collected but exit pipe open to atmosphere. A whole range of test figures were obtained at full throttle with the air box pressure varying from ground level conditions to those at 15,000 ft. TABLE OF COMPARISONS. | | Full throttle 10,000 ft. | | | | Engine throttled under ground level conditions. | | |---:|:---:|:---:|:---:|:---:|:---:|:---| | | Air boxes Inlet temp: +15º C. | | Corrected for alt: conditions. Air temp. -5º C. | | | | | TEST. | 2250 | 2500 | 2250 | 2500 | 2250 | 2500 | | (1) Original standard cams. | 435 | 485 | 473 | 529 | 437 | 462 | | (2) After flight tests | 442 | 493 | 481 | 538 | 455 | 485 | | (3) Long duration cams. | 460 | 515 | 500 | 562 | 476 | 512 | contd :- | ||