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).
20 HP engine's exhaust cutout, comparing acceleration and max speed with the cutout open and closed.
| Identifier | ExFiles\Box 74\4\ scan0160 | |
| Date | 17th December 1924 guessed | |
| 20 HP. EXHAUST CUTOUT REPORT. HP. Curve comparison - Cutout open and closed, taken on Test Bed, is attached. Road Tests. (The figures given below are the averages of several tests, which showed very close results.) (1) ACCELERATION. (a) Distance ¼ mile, starting speed, finishing speed and time taken recorded :- | Starting speed. | Finishing speed. cut-out open. | Finishing speed. cut-out closed. | Time. cut-out open. | Time. cut-out closed. | |---|---|---|---|---| | 20 | m.p.h. 51.5 | m.p.h. 50 | secs. 48.4 | secs. 48.6 | | 30 | 52 | 50.5 | 43.6 | 44.2 | (b) Time taken to accelerate from 10 m.p.h. to 30 m.p.h:- C.O. = 15.8 secs. C.C. = 16.03 " 30 m.p.h. to 50 m.p.h:- C.O. = 31.4 secs. C.C. = 32.1 " (2) MAX: SPEED. No appreciable increase in speed can be noticed by opening the cut-out when going all out with cut-out closed. contd:- | ||