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).
Various engine and drivetrain issues observed during testing, including oil leaks, manifold failure, and clutch performance.
Identifier | ExFiles\Box 97\4\ scan0175 | |
Date | 23th November 1938 | |
-4- RM{William Robotham - Chief Engineer}/IMW{Ivan M. Waller - Head of Chateauroux}3/R.23.11.38. Slight oil leaks occurred from the engine front past the acme thread, and from the rear main bearing into the clutch housing. These leaks were no more than usual under the conditions. The engine otherwise kept very clean and the rocker cover joint remained oil tight throughout, attributed to the rubber washers in place of springs on the holding down nuts. Previous rocker covers have always leaked by the end of the mileage. The rear exhaust port joint failed at 11,625 miles due to distortion of the manifold. A new manifold was fitted and was distorted in a similar manner after 6356 miles. The same trouble occurred on the Wraith in France. A stiffening web in the manifold is required. Flatness at 1800 r.p.m. on pick up was experienced due to tracking in the bakelite of the Delco distributor top. Sparking between the plug leads inside the conduit was also suspected, and B.I. Neoprene insulated H.T. wires were fitted for the last 4527 miles to overcome this trouble. Rapid wear of the strengthened rubbing blocks in the contact breaker arms was experienced in England and subsequently on the new arms fitted for France. The engine was free from detonation on Esso, Azure or any of the "Supercarburants", but pinked badly up to 30-40 m.p.h. on "Tourisme". The automatic starting carburetter is not yet as satisfactory as the present standard starting arrangement; development work is in progress. Average petrol consumption 13.7 m.p.g. Castrolite oil used. Average consumption 2070 m.p.g. Best measured consumption 3092 m.p.g. The Long centrifugal clutch remained free from jaggers throughout the mileage, and was smooth in operation. No servo spring was fitted, nor is one required. Slight slip was experienced on one or two occasions, attributed to the oil which escaped from the gearbox into the clutch housing. The amount which reached the facings was extremely small. The slip was not sustained at higher revs, thanks to the centrifugal action. The original clutch trunion to GCD.518 seized on the aluminium spigot during the preliminary running in England. A modified trunion to GCD.824 & 891 was fitted and completed 12,731 miles without any trouble. | ||