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).
Test report on 'Engine Unit No.7' detailing performance metrics and issues encountered during mileage trials.
| Identifier | ExFiles\Box 97\5\ scan0201 | |
| Date | 2nd June 1939 | |
| -3- Engine Unit No.7 - Cont'd.{John DeLooze - Company Secretary} Auto ignition when switching off and indications of steam pockets were noticed, but no trouble occurred as a result of this during the first 25,000 miles. During the last 5,000 miles an exhaust valve broke, and the exhaust seats in the cylinder head cracked. Strengthened exhaust valves have been instructed for production, and improved cooling for the cylinder head is being developed experimentally. The petrol pumps completed 50,000 miles, and when checked on the Autostrada near the end of the mileage either side was satisfactory for sustained maximum speed. The rear half had been examined and re-set after the first test but the front half was not disturbed throughout the two tests. The average petrol consumption for the mileage was 14 m.p.g. Castrolite oil was used in the engine and with the General bye-pass filter the oil was not changed during the 31,800 miles, after which analysis by Wakefield's and our Laboratory showed that the lubricating properties were to all intents as good as new oil. The average consumption was 2900 m.p.g. and the filter cartridge was replaced on the average, every 5,000 miles. The oil pressure was 30 lbs/sq.in. over a wide range of normal conditions and there was no tendency for it to fall off at high temperatures. The maximum speed under very favourable conditions was 98-100 m.p.h. An average of 87 m.p.h. was maintained for 53 minutes on the Milan-Turin Autostrada and during the run the following data was obtained:- Air temperature - 12°C. Maximum water temperature - Bottom tank 75°C Cylinder head 85°C. Maximum oil temperature - 108°C. Oil pressure 32 lbs/sq.in. at 3650 r.p.m. = 90 m.p.h. | ||