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).
Test results comparing crankshaft vibration with a standard versus a new spring drive and damper on a 20 HP engine.
| Identifier | ExFiles\Box 6\1\ 01-page076 | |
| Date | 31th October 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Tsm. c. to WOF. SJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} SY. c. to OY. 15020 Hs{Lord Ernest Hives - Chair}/Tsm1/LG31.10.27. 20 HP. SPRING DRIVE AND CRANKSHAFT DAMPER. (16=7) We have been doing some further tests on a combined spring drive and crankshaft damper on the 20 HP. engine. This spring drive is on the same principle as 1-G-1. The experiments have been done with the complete car on the dynamometer in order to get a more concise idea of the amount of vibration transmitted to the passengers. With the standard spring drive the periods of crankshaft vibration are :- Engine R.P.M. M.P.H. Top gear. 3rd. gear. Severity. 3300 64 42 Dangerous. 2200 42 28 Very noticeable. 1650 31 21.5 Bad. 1100 21.5 14 Slight. The speeds with the new spring drive are as follows :- Engine R.P.M. M.P.H. Top gear. 3rd. gear. Severity. 3550 47 Very bad. 2910 35 Noticeable. 2090 27 XXXX Bad. 1705 21 Very slight. 1390 18 Slight. 1085 14 Doubtful The 2090 r.p.m. period is approx. as bad as the 1650 period with the standard spring drive both without damping. contd :- | ||