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).
From 'R' to 'BY' detailing issues and proposed improvements for various engine components, including the Goshawk II.
| Identifier | Morton\M1.4\ img015 | |
| Date | 9th November 1921 | |
| TO BY.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} -3- R7/G9/11/21 Contd. sloppy control of the ignition when the engine is not running or running very slowly; a reason why we made our ignition of the pattern we adopted. A slight improvement may be made in our governor by making more shapely balls. With regard to the condenser for the battery ignition, perhaps Mr. Beaver of Glovers would advise us on condenser materials. Mr. Hives reported that the Bosch condenser under alternating current tests becomes hot and loses a great deal of capacity, but completely regains its lost capacity on cooling. (9) VALANCE ABOVE PETROL TANK. I agree something might be done to cover up the space existing between the petrol tank and the body, but it is difficult as the valance provided for this purpose should be made easily removable to provide a way in for lubricating the brake gear on the back axle. This part of the work has been given to Mr. Evernden to draw, and also an alternative scheme of carrying the spare wheel on the running board, and so permitting a luggage carrier at the rear, which will be drawn at the same time. (10) CYLINDER BLOCK. Since the pistons have been a little trouble, it occurred to me that the cylinder block may distort through various causes, such as a newly made casting, the bolting to the crankchamber, the influence of the head etc. This might go through an examination after being used, and while bolted up to crankchamber. The Works are going to attempt casting the cylinder snouts to size to avoid machining, and to have a straight bedding strip all round the bottom of the cylinder block for the face which is bolted to the crankcase. Y3348 (11) COMMUTATORS. I would prefer mica to bakelite-micarta for separating the commutator bars of the commutators for "Goshawk II". X3485 (12) BATTERY IGNITION. The range of the battery ignition governor should be from 1000 to 2500 R.P.M. of the engine. After 2500 there need be no further movement. The governor spring should be still further set out from the last instructions given. The range of the hand advance on the battery ignition may have to be increased if we wish to ensure that the engine can be started on the switch. (13) OVER-OILING. It is found on the experimental Goshawk that the intermediate crankshaft bearings being narrow and provided with individual oil feed and grooves tend to throw out a lot of oil. I would like the oil grooving removed, and the number of the holes in the crankshaft reduced. Mr. Hives suggests that three feeds only to the crankshaft be used as per 40/50 engine instead of seven without prejudicing the reliability of the system. There are three remedies which we might try for reducing the over-oiling in the order numbered - | ||