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).
17-hour endurance test on a High Power Bentley for Le Mans.
| Identifier | ExFiles\Box 90a\4\ Scan224 | |
| Date | 20th May 1936 | |
| To E.{Mr Elliott - Chief Engineer} c. to RIC. Y262. Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}11/JH.20.5.36. Endurance on High Power Bentley for Le Mans. Further endurance has been carried out for 17 hours under the following conditions :- (1) Front 8 water holes blanked in the head making the water flow to the rear end of the head and traverse to the front. The resultant water temp. was 80°C. at the rear and 81°C - 82°C at the front outlet. (2) Mixture strength richened up from weakest maintained at .515 pts./BHP/HR. to .590 pts/BHP/HR. (3) Exhaust valves to Lec. 5115 arranged as follows No. 2 & 3 - Rs.{Sir Henry Royce's Secretary} 275. No. 6 & 7 Ex. 21586. No. 10 & 11 - Rs.{Sir Henry Royce's Secretary} 276. (4) Condition of run 30 mins. at 4000 R.P.M. full throttle. 25 mins. at 4250 " " 5 mins. at 2500 " " With test bed exhaust system. On several occasions the power began to fall to the extent of 6 H.P.H. and each time it was found that the exhaust valves had taken up the clearance. After resetting at .010 clearance the power would be normal again. From setting at .010 at 15 hrs. the clearance went completely on No. 2 exhaust valves at 17 hrs. | ||