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 report tabulating results of valve bouncing with different spring sets at various engine speeds.
| Identifier | ExFiles\Box 10\3\ 03-page019 | |
| Date | 16th March 1937 | |
| -2- Rm{William Robotham - Chief Engineer}/Mths{Reg Matthews}9/R.16.3.37. For the second test we removed the bottom tappet springs and at the same time removed spring to LeC.5417 and replaced them by a standard set of EB.175 spring. Results are tabulated below:- BOTTOM TAPPET SPRINGS REMOVED. R.P.M. | Rm.{William Robotham - Chief Engineer}260 Tempered Spring Co. | Rm.{William Robotham - Chief Engineer}260 by R.R. | E.B.175 --- | --- | --- | --- 4000 | No.1 Exhaust Valve bouncing. | No.4 Inlet Valve bouncing. | No.5 Inlet & No.6 Exhaust Valves bouncing. 4100 | No.1 Exhaust, No.2 Inlet No.2 ExhaustValves bouncing. | No.4 Inlet & No.4 Exhaust Valves bouncing. | No.5 Inlet & Exhaust No.6 Valves bouncing- 4200 | All bouncing | All bouncing | All bouncing. Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews} | ||