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).
60-hour endurance test performed on a standard Bentley engine unit.
| Identifier | ExFiles\Box 3\6\ 06-page259 | |
| Date | 11th June 1934 | |
| RE/VJH.2/KM.11.6.34. Endurance Test on Standard Bentley. A Bentley unit has recently successfully completed 60 hours endurance running on the test bed. The conditions of the test were :- Continuous running at 4000 r.p.m. full throttle. Air and test bed exhaust silencers fitted. B.H.P. approx. 100. Water temp. 80°C. Oil inlet temp. 90° " outlet " 115° The engine (Unit B.6. Spec. RRG/RSD.9/JM.{Mr Morley}23.5.34) was standard in all respects except for :- (1) From 0 to 50 hrs. and 56-60 hrs. High ratio cylinder head 7.05:1; with 1.500 dia. inlet valves and 1.200 exhaust valves. (2) From 50 to 56 hrs. standard cylinder head 6.67 C.R. and double valve springs. (3) From 23 to 60 hrs. C/A gasket replaced by 0.030 all metal gasket. No trouble of any kind was experienced during the test. There was no measurable drop in B.H.P. and no piston knocks developed. The exhaust valve tappet clearances were increased by 0.0035 during the run. A power curve taken after 53 hours running is shown on the attached E.V. The oil consumption is shown on E.V.37. It can be seen that the consumption has definitely increased although the figure 1 - 1½ pts/hr. shown for the first 3 hours is unreliable and may have been as high as 2 pts/hr. The consumption from 35 hours onwards was 2.66 pts. per hour. The amount of external oil leakage probably did not exceed 4% of the consumption. | ||