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).
Letter from Vauxhall Motors discussing vehicle testing methodologies, particularly wide gaps and test loads.
| Identifier | ExFiles\Box 127\4\ scan0177 | |
| Date | 20th February 1940 | |
| 1697 Vauxhall Motors Ltd TELEPHONE NUMBER 2600 LUTON. LUTON. BEDS. TELEGRAMS CARVAUX, TELEX, LUTON WHEN REPLYING PLEASE QUOTE → OUR REF: 289/AT/IF YOUR REF: Rm.{William Robotham - Chief Engineer}11/MH{M. Huckerby} 20th February, 1940. W.A. Robotham, Esq., Messrs. Rolls-Royce Limited, Derby. Dear Robotham, Confession is good for the soul. Perhaps you are "stuck" in your progress on wide gaps due to some other limiting factor. I don't know what your methods of test are but you know that wide gaps are only good at road loads. The lighter the load the greater the effect. Loads needed to roll our small cars along at 20 and 30 M.P.H. are small, whereas your loads for rolling your land yatch along may be considerable. We, because of this sensitivity, have found it necessary to be very particular about our test loads. In a job as small as our ten we show 3 M.P.G. variation at 25 M.P.H. due to Barometer, and have been forced to correct the beam load setting to sea level in order to be able to show up small gains or losses. If we don't do this the throttle position is never the same for the same conditions. Likewise, you know that each type of spark plug has its own limiting factor as does its 1. | ||