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).
Thermostat issues and revised settings for the Bentley M series chassis.
| Identifier | ExFiles\Box 156\2\ scan0120 | |
| Date | 7th September 1938 | |
| 132-8 To EA. c. to.RHC.{R. H. Coverley - Production Engineer} c. to BY.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/Std.6/JH.7.9.38. BENTLEY M SERIES THERMOSTATS. A good deal of trouble has been experienced on M series chassis with incorrectly set thermostats and this is admittedly the makers fault. We have taken the matter up with the makers in order to prevent a repetition of the trouble (see attached copy of letter) and this should avoid any further faulty units. For the guidance of the Test Department however, we would mention that a correctly set thermostat to EB.3509 is set to open at 76°C., and will give a running temperature on the road which will vary between 77 and 85°C (excluding idling conditions) with an average running temperature of 80°C. We recommend that any thermostat which gives running temperatures within the range of 75° to 85°C. should be accepted as satisfactory. After the first hundred chassis in M series however, we hope to standardise a modified thermostat unit which has a smaller bellows and larger valve - a standardisation sheet is being circulated for this purpose. This new unit will have a revised setting of 79°C.±1 opening temperature and will give a much steadier thermostat reading - again however, we recommend that any unit which gives working temperatures within range 75 - 85°C is acceptable. Rm{William Robotham - Chief Engineer}/td. | ||