Running report on vehicle 27-G-V1, detailing mileage, consumption, and the condition of engine components.
| Identifier | ExFiles\Box 7\1\ 600b 27 G V1 Mx Car-page88 | |
| Date | 20th April 1939 | |
| Mx. {John H Maddocks - Chief Proving Officer} 4/W.20.4.39. REPORT ON RUNNING OF 27-G-V1. Mileage since fitting parts for C. or future series as detailed in Mx. {John H Maddocks - Chief Proving Officer} 10/W.21.11.38 ... 14,907. This mileage includes 1,300 which has been run in London traffic. Total mileage run by Mx. {John H Maddocks - Chief Proving Officer} .......... 36,701. Average petrol consumption 15 M.P.G. Average oil consumption. 3000 M.P.G. Engine. Continues quiet and smooth. Slow running fairly good, no loss of compression. Cylinder head dismantled at 12,204 miles and valve seats examined. There was a slight amount of distortion of valve seatings in the vicinity of bridge between inlet and exhaust valves, but no sign of cracks. At a mileage of 10,424 No.7. Exhaust valve stuck open. Cylinder head was dismantled and a new valve and guide fitted. The faulty valve and guide were handed to BY and Rr. for examination. Trouble appeared to be due to carbon deposit being transferred from valve stem to guide thus reducing clearance, resulting in seizure. No trouble has been experienced with the remaining valves. Pistons. With modified dimensions to reduce risk of seizure due to carbon formation on top land. Pistons had carbon removed from tops at 10,424 miles and after a further mileage of 1,780 were removed for examination. There was considerable improvement in the condition of the top lands as compared with a set of standard pistons previously run and other pistons which have been examined from time to time on customer's 25/30 cars. | ||
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).