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).
Report from France detailing tests on valve clearance, axle arrangements, and solutions for clutch jagger.
| Identifier | ExFiles\Box 5a\4\ 04-page094 | |
| Date | 21th August 1934 | |
| 101534 5840 Hotel de France, Chateauroux, Indre. France. 21st August 1934. To Hs.{Lord Ernest Hives - Chair} From G.W.H. c.c. Rm.{William Robotham - Chief Engineer} 4 B IV. The decreased valve clearance has again been a factor in spring breakage. We ran 2,000 miles without any failure with .006 clearance, then after reducing the clearance to .004 and .003 the springs failed in a 1,000 miles. The valve noise is not decreased by the alteration of .001" on the inlets and .002" on the Exhaust. We have examined the valves and seatings, and there is no sign of barring. Re axle and front cross member. I have made arrangements with Sr. to fit the cross member to their Trials Car B-130-A, and also try the 4° traverse axle at the same time. Sr. is going to hold the car up Thursday and Friday, and Saturday if necessary. He starts his holidays on Saturday, but is willing to delay them so that we can get our tests through. We shall therefore go up with 41 G 1V Wednesday night, taking the axle with us. Re clutch jaggers. On 48-MX{John H Maddocks - Chief Proving Officer} we made the spring loaded link from the pedals to the crankcase solid. This lessened the jaggers 50%. Then we found that no set up had been made to the two rubber cushions. We therefore set them up two complete turns which reduced jaggers further. Shenttried three complete turns, but with not much betterrresults. The engagement is now more of a snatch or grab than a jagger. The movement of the clutch take up is very small and it is all or nothing. It strikes one very forceably that the cushions are having to do at the small radius to cushion the mass of weight of the engine and gear box unit. One would imagine that they should be double the size and have a greater leverage to be of much benefit. We have had to take off the lagging on the front expansion box, to give it clearance between the tie rod as it clanked and created a terrible noise, with the movement of the engine. SIG IV. With the raising of the gear box end, i.e.- packing the rubber up, has made a remarkable difference to the smoothness of the engine. It has taken away the roughness at high speed. also the pedals are very much more steady. It has also improved clutch jaggers, but this clutch is like 48-MX{John H Maddocks - Chief Proving Officer}, it grabs now more than jaggering. We have tried making the two stays from the front cross member to the engine case more solid, by fitting tight bolts, but it did not make any difference to the clutch jaggers. | ||