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).
Engine performance, oil consumption, and component condition following extended mileage testing.
| Identifier | ExFiles\Box 101\2\ scan0221 | |
| Date | 1st January 1937 | |
| -2- Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}/HFH{Hoppy F. Hamilton}3/R.1.1.37. to be difficult. It was thought that dampness or condensation on the plugs may have been the cause, but as this only happened on two occasions we were unable to confirm this. At 24875 miles the engine oil was drained and the bearings examined before continuing the running with Mobil-arctic oil. The oil consumption increased from an average of 1300 m.p.g. using Castrol XL to 925 m.p.g. using 'Arctic'. Oil pressures were lower throughout the range, and were 19-21 lbs at 70 m.p.h., while not more than 2-3 lbs could be obtained under idling conditions. The engine was smooth and free from noticeable crankshaft periods throughout the range. The engine gears were quiet over speeds of 400 m.p.h., but below that speed there was a noticeable gear rattle when the engine tended to idle unevenly. A bad water leak developed from the water pump gland, which had to be re-packed. This had been previously done after the engine had run 10,000 miles. The general impression obtained by fitting the deturbulated head was that an extra general smoothness was present throughout the running range as compared with the fully turbulated head, but that a small degree of acceleration performance had been lost. The maximum speeds only differed by 2 m.p.h., the highest speed was recorded using the deturbulated head. BEARINGS. IOP.F.60757. Main bearings in W/Mt. Intermediate bearings grooved Ex.19004/5. Connecting rods IOP.F. 60840. E.B. 2815/6 Connecting rods and caps. Big end bearings in Hall's solid metal. The bearings were removed for inspection before continuing running with Mobil-Arctic oil. The big end bearings were found to be in excellent condition. | ||