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).
Shock damper valve tests, comparing maximum valve lifts for Standard, Double Area, and Reduced Length Seat valves.
| Identifier | ExFiles\Box 151\2\ scan0039 | |
| Date | 24th March 1933 | |
| To Hdy. {William Hardy} from Hs {Lord Ernest Hives - Chair} /W.Bell. Hs {Lord Ernest Hives - Chair} /WB. {Mr Brazier / Mr Bell} 6/KT.24.3.33. N.S.3497. SHOCK DAMPER VALVE TESTS. The following table shows the maximum valve lifts obtained when using, Standard, Double Area, and Reduced Length Seat valves (the latter being a standard .250 diam. 28º valve the L.P. seat of which was reduced to a length of .025"), in conjunction with 172 lb/in. and also 100 lb/in. valve springs. The figures indicate the maximum distance of the valve from its seat, and not necessarily the movement of valve per stroke since it is not known whether the valve returns to the seat or not. | Rig Speed R.P.M. | Equivalent Mean Axle Velocity Ft/Sec | Standard Valve 90/90 lb. | | Double Area Valve 90/90 lb. | | Reduced Valve Seat 90/140 lb. | | |---|---|---|---|---|---|---|---| | | | Valve Spring 172 lb/in | Valve Spring 100 lb/in | Valve Spring 172 lb/in | Valve Spring 100 lb/in | Valve Spring 172 lb/in | Valve Spring 100 lb/in | | 90 | .25 | .028 | .029 | .034 | .030 | .010 | .011 | | 180 | .5 | .034 | .040 | .040 | .037 | .013 | .015 | | 360 | 1.0 | .042 | .046 | .046 | .045 | .019 | .021 | | 540 | 1.5 | .056 | .060 | .055 | .062 | .029 | .030 | From these results, the double area valve apparently makes practically no difference to the valve lift, whereas reducing the length of the valveseat makes a great difference. N.S.3497 Valve Tests. Indicator diagrams were taken with these three types of valves using 1" stroke. The Standard valve curves showed a steady press-velocity effect with smooth even curves illustrating absence | ||