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).
Endurance testing issues with the distributor, AC petrol pump, and dynamo, with proposals for further tests.
| Identifier | ExFiles\Box 123\5\ scan0290 | |
| Date | 1st February 1939 | |
| -12- Since dropping the last Monichrome shaft and using the normal S/ZN shaft no further trouble has been experienced on the wear of the distributor driving teeth. During the endurance run, slack has developed in the distributor, which will be investigated on dismantling. As reported in our memo Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}9/MH.{M. Huckerby}15.1.39, it is necessary to retain the oil release hole at the rear end of the camshaft. After 35 hours endurance the AC petrol pump failed in its delivery due either to wear of the operating push rod or the cam, as yet we do not know which. It is assumed that the AC mechanical pump will be used with an electric pump for starting, as by itself with an empty floatchamber, it is necessary for the starter to turn the engine over 10 to 15 times before the floatchamber is full and the engine starts. At the present time the battery has little reserve for the ignition when starting cold and this condition will be accentuated with a mechanical pump only. ELECTRICAL EQUIPMENT. Two different types of dynamo have been run, the first giving trouble due to lack of a locking device behind the terminal, also the clip type of cover came adrift, the S.B.A. screws stripping due to vibration. A more robust method of locking should be provided as the cover slips round and shorts the field and positive terminals. The improvised strengthening of the dynamo stay has prevented further failure of the dynamo support as experienced on the original design. The CAV regulator used with dynamo allows a very high charge when starting and registers up to 24 amps. FURTHER TESTS. Although our work on the engine has only be regarded as preliminary, we have obtained sufficient data to go forward with the following:- (1) Crank journal size increased from 2.5 to 2.75 giving increased stiffness and reduced bearing load. This can be carried out with only .050 machining of the crankcase by using Vandervell thin shell bearings as against our standard thick shells. | ||