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 on the performance of hydraulic adjusted tappets.
| Identifier | ExFiles\Box 17\6\ Scan339 | |
| Date | 20th March 1935 | |
| LP{Mr Lappin} Smith x454 Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}28/KW.20.3.35. 28-EX Tests Carried out with Hydraulic Adjusted Tappets. (1) Hydraulic tappets in operation, erratic slow running below 8 m.p.h. (2) Hydraulic adjustment cut out. Valves set to have .002 tight clearance. (3) Erratic slow running below 8 m.p.h. (4) Hydraulic adjustment cut out. Valves set to .003, .004 and .005. Slow running erratic until .005 setting was reached. (5) Hydraulic tappet adjustment cut out. Valves set with a clearance of .002 tight. Car left out all night, moderately cold. (6) Valve clearances checked before engine turned. I E E I I E E I I E E I 2 4 5 6 10 12 Tappets just free 1 7 8 9 Tappets .002" clearance turning engine to check. 3 11 Tappets just free. (7) Engine started up in 5 seconds, tappets quiet. (8) Hydraulic adjustment still cut off. Valves set with .006" clearance. (9) Slow running test. 4 m.p.h. steady running obtained, pulsation of engine felt. (10) Hydraulic tappets dismantled and bench test taken of time and load required for leak of plunger. Oil and plunger unit kept at a constant temperature of 80°C. (see chart). | ||