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).
Issues and suggestions regarding the camshaft drive, valve gear, sparking plug positions, and fuel consumption on the 40/50 HP chassis.
| Identifier | ExFiles\Box 183\M22\ img128 | |
| Date | 8th October 1920 | |
| Contd. -2- Camshaft Drive. X.3310. The top universal, Mr. Royce suggests, could have vanes on the outside for pumping down the oil. The serrated joints should have entering curves on the teeth like the gears in the gearbox which slide into engagement with each other. Valve Gear. When replacing the valve gear on the cylinders, it was found that the rockers fell too far and prevented the valve gear from being pulled down into position. The features which limit the downward stroke of the rockers require to be increased in height. Sparking Plug Positions. X.3587. The Goshawk engine as brought here had the sparking plugs pointing towards the dashboard. This is not correct, as it is then impossible to remove the sparking plug from No.6 cylinder. The plugs should point forward towards the radiator, as shewn on the arrangement of valve gear Lec.1201 and other drawings. The weight of the engine seems very good, and should be given. CONSUMPTION ON 40/50 H.P. CHASSIS. X.3923. X.3056. Chassis 6.EX was used for the journey, and did a consumption of 27 m.p.g. with the engine stopped when descending hills. Mr. Royce thinks we ought to have a demonstration of consumption, but with the clutch in and the engine turning over all the time, as in ordinary driving. Mr. Hives thought he could get 23 miles per gallon under these conditions, and said that any driver with a little tuition as regards not using brakes etc. would be able to obtain the same results. It was necessary for the car to be so free that it could be pushed about by hand, and also the tyres should be fairly hard. The Michelin Company were said to have demonstrated that cord type of tyre required less tractive effort than the canvas type. Mr. Royce thought that we should take a customer's driver only recently acquainted with R.R. cars, give him the necessary tuition, and see if he could obtain a good consumption. We should then be prepared to give a demonstration of this point. We should also find out in our experimental work whether it is possible to make an engine to run more freely, by alterations to pistons etc. The thermostatic control of the water temperature also assists in obtaining good consumption. THUD ON 1.EX. Mr. Hives says that a slight thud is a feature of our engine, and occurs on No.6 cylinder with the firing in the intermediate position. This slight thud disappears after the engine has been in use for a little while. Contd. | ||