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).
Wear and performance issues of Goshawk-11 engine components, including the crankshaft, clutch, gearbox, and universal joint.
| Identifier | ExFiles\Box 46\2\ Scan249 | |
| Date | 1st March 1932 | |
| contd:- -3- The crankshaft wear is very little. The most serious complaint with Goshawk-11 engine is a high speed vibration which comes on at over 3000 R.P.M. 5-Goshawk-11 which has completed 10,000 miles at exceptionally high speeds in France, showed no signs of this vibration causing any harm. The taper on the end of the crankshaft which she always shows signs of pitting when the vibration is serious, is in perfect condition. 5-Goshawk-11, we believe, may be an exception. It was noticeable that 6-Goshawk-11 which is at present running in France, was much worse for this vibration and we are certain to receive complaints with regard to it. There is also another complaint of a rattle we get from the pinion driving the dynamo when the engine is running at very low speeds. This noise comes on just at a time when one would be demonstrating the quietness of the engine. It will certainly be complained of. We have proved that this rattle is worse if the friction in the spring drive is only a small amount. It does not occur if we make the spring drive solid, but we have this rattle take place when the spring drive is adjusted to give the best all round results. This noise can be overcome by a slight braking on the dynamo drive spindle. Another complaint is the flats formed on the rollers on the rockers; this is a general complaint. We are running 7-Goshawk-11 with more slack on the rollers on the pins, also sideways. So far this has not run very far but from examination we believe that flats are still being formed. We have instructions to try larger rollers, which will be put on a car at the earliest moment. We have still to find a definite cure for the oil leaks from the rear end of the engine. It was noticeable on 5-Goshawk-11 when the engine was dismantled, that owing to the spacing of the bolts holding the bottom half at the rear end of the engine, it did not appear as though a good oil joint was being made. It is impossible to see when the engine is built up, where the oil is actually leaking from. CLUTCH. The setting of the steel driving plate so that it provides a certain amount of flexibility for the first take-up of the clutch, has improved the action of all clutches tremendously. We think his is a very big point because on 1-Goshawk-11 we had the rear axle shaft break on one side, and found it badly twisted on the other. This car had been used for experimental work on clutches and at times has been run with a fierce clutch. The axle shafts on 5-Goshawk-11 had not twisted at all. One can notice, of course the difference in the time taken for the clutch to stop with the gear box oil cold and hot. GEAR BOX. The gear boxes have given very little trouble. The continuous gears on most of the cars make a dry harsh note. It has been proved that this noise comes from the gears and is not affected by the bearings. There appears to be condensation inside the box which forms rust on the locking mechanism and lever. A vent is being fitted to overcome this. UNIVERSAL JOINT AND PROPELLER SHAFT. The universal joint on 5-Goshawk-11 had a fair amount of slack due to wear. contd: | ||