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 component faults discovered during mileage testing.
| Identifier | ExFiles\Box 108\1\ scan0191 | |
| Date | 10th September 1937 | |
| 3. During one days running at the end of the mileage a loss of clearance of .004" on the exhaust valves was noted. There appeared to be too much oil on the rocker gear, and the exhaust was inclined to be smoky idling. It is agreed that the present feed to the valve tips is excessive and experiments are being carried out to reproduce the same system which proved successful on 32-MX{John H Maddocks - Chief Proving Officer}, namely copious supply to the push rods, and the bare minimum to the valve tips necessary to prevent them drying up. When removing push rods the bottom tappets lifted out of their guides and were not easily replaced. This will receive attention. No. 7 valve spring in Swedish wire fractured after 634 miles. There were no other valve spring breakages. No. 6 exhaust valve (no. 3 cylinder) fractured after 6,500 miles. The head fell into the cylinder causing damage which rendered further running impracticable, and the car was driven back to the Works. A general re-design of the valve gear is in progress. Carburetter LeC.5626 - 32 - 33. Production Stromberg 25/30. A bad flat spot occured at 12 m.p.h. on light throttle. Difficult starting when cold was experienced due to the choke sticking. This was cured by loosening off the clamp bolt on the pipe from the air silencer. Carburetter Air Silencer. LCP. EX. 568. The end which carries the filter element came loose in the body. A modification has been brought out to overcome this trouble. Fan. LCP. EX. 954. The fan was very noisy. Research on this trouble is in progress. The blades were standard 20/30 design, but pressed in one piece. Engine Gears. Ex.27115, Ex.27042, Ex.919. The gears rattled at the start, but became no worse during the mileage. This was attributed to excessive backlash. | ||