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).
To determine the accuracy of checking valve timing by hand compared to when the engine is running.
| Identifier | ExFiles\Box 48\4\ Scan105 | |
| Date | 16th August 1923 | |
| R.R. 493 (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} X4226 EXPERIMENTAL REPORT. COPIES TO: R.C.J. WOR{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} EP.{G. Eric Platford - Chief Quality Engineer} EN-OK Expl. No. X.1770 / X.4226. REF. HS{Lord Ernest Hives - Chair}3/LG16.8.23. OBJECT OF TEST. To determine whether checking valve timing by turning the engine by hand gives an accurate reading of what takes place when the engine is running. TESTER. A.{Mr Adams} J.{Mr Johnson W.M.} Lidsey. CONDITIONS. ENGINE - 2-GOSHAWK-11 - RUNNING ON TEST BENCH ALL FITTINGS STANDARD. A low tension make and break was fitted up and operated by No.1 Inlet valve rocker arm and set so that the points broke 20º before the valve closed. The flywheel was marked off in degrees and lit up by the H.T. spark gap from coil and H.T. condenser SUMMARY OF TEST. Before taking any results, the apparatus was checked for accuracy by making the spring drive choc-a-bloc, and looking for any variations in the timing of the spark. It was found that there was a very slight variation viz. - 2º. This was proved to be due to slack in the timing gears, by connecting an H.T. ignition lead to the spark gap - the variation was the same in this case. Results. It was found that turning the engine over by hand to check the valve timing gives an accurate reading within 2º of the valve timing when the engine is running. The actual timing being 2º later than that obtained by turning the engine by hand. This inaccuracy disappears if the damping springs are removed from the spring drive, when the engine is turned by hand. contd:- | ||