The running performance and component status of engine 27-G-V1.
| Identifier | ExFiles\Box 7\1\ 600b 27 G V1 Mx Car-page29 | |
| Date | 2nd June 1938 | |
| Mx. {John H Maddocks - Chief Proving Officer} /2.6.38. REPORT ON RUNNING OF 27-G-V1. Total mileage run by Mx. {John H Maddocks - Chief Proving Officer} 6,370 - 3475 miles since fitting :- (1). White metal bearings to engine. (2). Attwater fine grain material Cam Wheel. (3). High geared axle, etc. Oil consumption 1950 m.p.g. Petrol " 14.3 m.p.g. Water temperature for average running 78°. Engine. No measurable slack has developed in the timing gears which remain quiet and free from rattle. No camshaft balancer fitted. Slow running deteriorated after 3000 miles running. This has been made normal by refacing valve seatings. Slight warping of the inlet valve seatings had occurred at the narrow bridge between inlet and exhaust valves. This feature is being investigated experimentally. A front exhaust manifold stud has broken. After the breakage the car was run a further 1,800 miles without any sign of exhaust blow, this proves the breakage was not due to distortion of the manifold. We are of the opinion these breakages occur due to bending of the end studs due to expansion and contraction. The studs are normally in KE.965 material. These have been replaced on BY's recommendation by studs in 3½% nickel as breakages are not prevented by the use of KE.965 and furthermore, a broken stud in this material is very difficult to remove. Carburation. Idling on up gradient and starting hot have been made satisfactory by lowering the petrol level to a dimension of .750" measured from the top face of the float chamber. cont'd. {John DeLooze - Company Secretary} | ||
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).