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).
Testing hydraulic versus solid type plungers with a new camshaft on chassis 3.CP.144.
| Identifier | ExFiles\Box 146\5\ scan0192 | |
| Date | 6th July 1939 | |
| 1245 To Rolls-Royce Ltd. Derby ......... Br/H.R. (crossed out) Copy to ...... Mar/SD. (crossed out) Rm.{William Robotham - Chief Engineer} H.{Arthur M. Hanbury - Head Complaints} Swell Roles (Handwritten signatures) Sr. is absent Levallois VA4/ET.6.7.39 Re: CHASSIS N° 3.CP.144 - Mr. FRANCQUI With reference to Sr/VA5/ET.26.6.39, the following is our report concerning the result of trying out hydraulic type plungers in conjunction with a latest type camshaft (E.68760). 1. We firstly fitted up the engine with the above type of camshaft and with solid type plungers and, after generally tuning up the slow running, with engine idling and on the road, it was found to be very good and quite up to standard. 2. We then removed the solid type plungers and fitted the hydraulic type and the slow running was then found to be very poor, both when the engine was idling and on the road. Before coming to the conclusion that it was the new type camshaft in conjunction with hydraulic plungers which was the cause of the trouble, we made doubly sure that the hydraulic plungers and the rocker mechanism in general was functioning correctly. We were unable, however, to obtain good slow running and therefore could not pass the car off test. We then removed the Hydraulic plungers and refitted the solid type. The slow running was then once more restored. We explained the above to "H" who agreed that, under the circumstances, it would not be worth going to the expense of removing the new camshaft and refitting a new or reconditioned one, especially as we were expecting the owner to call or send for his car on the same evening. The solid type plungers have therefore been retained. VA. | ||