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).
10,000-mile report on vehicle 25-EX, detailing engine performance, specifically issues with torque dampers, pistons, and valves.
Identifier | WestWitteringFiles\W\May1931-August1931\ Scan092 | |
Date | 5th August 1931 | |
To Hs.{Lord Ernest Hives - Chair} From G.W.H. Hotel de France, Chateauroux, FRANCE. 5/8/31. REPORT ON 25-EX AT 10,000 MILES. ENGINE UNIT NO.21. The engine has remained good for power and acceleration throughout the mileage. We carried out a considerable amount of expl. work in conjunction with the diamond engine mounting. From these tests we obtained very good results in reducing booms and reducing the torque reaction effect. The loads on the friction surfaces of the torque reaction dampers, to obtain these results, were, 35 lbs with a leverage of 5.25". We observed, after approx. 5,000 miles, a fidgeting of the centre plate of the torque reaction dampers. We dismantled the dampers to ascertain the cause. We found that the centre plate had become loose at its anchorage, the plate having fidgeted on the spigot, also the plate had been burred up round the centre elongated hole, due to the movement of the engine. Sketches of this and reports were sent to Derby. We have since fitted new centre plates with a redesigned anchorage and the elongated hole having more clearance for the movement of the engine. We have not run sufficient mileage since the fitting of these to observe any defects. There are pulsations of the engine when the engine is idling. The pulsations cause a dithering of the front wings, and can be felt in the car. When travelling over rough surfaces, such as cobble stones, at medium speeds, one can observe and feel, the movement of the pedals. The absence of booms, and the general smooth running of the engine, we are of the opinion, more than justify the two faults mentioned. PISTONS. E.82041. - LONG SKIRTS. We have not, up to the present mileage, heard any piston knocks either cold or when hot. We also have not had any sign of the pistons overoiling. The carbon deposit was not more than normal on the tops of the pistons. VALVES & FITTINGS to LOP.E.78569. E.78492 Inlet Valves (S/SLV.) E.78493 Exhaust Valves (S/SLV.) E.80240 Valve Springs. We have had considerable trouble with the loss of clearance taking place in the exhaust valves. This condition became so frequent that we obtained and fitted, a new set of exhaust valves. We have, since the fitting of the new valves, | ||