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).
The effectiveness of a cam balancer in reducing gear rattle, concluding it can be discarded for cost savings.
| Identifier | ExFiles\Box 136\1\ scan0276 | |
| Date | 19th January 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}4/JH.19.1.38. cam balancer and on several units have tried with and without it and found that it does not make the slightest difference whether the unit has a gear rattle or not. The last unit upon which the effect of the balancer was tried had gears with .005 backlash and our next move is to try its effect on gears having excessive backlash. Based on these results the 15,000 mile car 26.G.VI. has the cam balancer plungers removed and is equipped with an end thrust plunger on the camshaft. Although as previously stated, no merit can be found for the cam balancer we want to be absolutely sure before we say that it can be discarded which if possible will result in a factory saving cost of approx. 30 shillings. per car. The points which we consider have reduced its effective-ness on Wraith as compared with the present production Bentley and 30 H.P. are as follows. (1) Reduced valve lift and consequent reduction of valve gear loading on the cams. (2) Additional damping friction of the cone face tappets and wall friction in the guides. (3) The dynamo pinion has more constant and heavier drive load, driving - (a) Oil Pump. (b) Water pump. (c) Distributor. (d) Dynamo. and in comparison with Bentley and 30 H.P. which drives only the dynamo. Our last engine on test had a gear rattle which in the time available we could not solve. | ||