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 Nash & Thompson discussing engine detonation issues, also known as pinking, in a car.
| Identifier | ExFiles\Box 126\3\ scan0131 | |
| Date | 29th April 1941 | |
| 1064 NASH & THOMPSON LIMITED DIRECTORS: A.{Mr Adams} FRAZER-NASH, M.I.A.E.,A.M.I.MECH.E. E.{Mr Elliott - Chief Engineer} GRATTAN THOMPSON. C. B. LOWE ENGINEERS CONTRACTORS TO H.{Arthur M. Hanbury - Head Complaints} M.{Mr Moon / Mr Moore} GOVERNMENT. Telephones: ELMBRIDGE 5700/6 OAKCROFT ROAD, TOLWORTH, SURREY YOUR REF. RM.{William Robotham - Chief Engineer}10/ML. OUR REF. 463/A/B.AFN/MH.{M. Huckerby} 29th April, 1941. W.A. Robotham, Esq., Rolls-Royce Limited, DERBY. Dear Mr. Robotham, Many thanks for your letter of the 24th. It was very kind of you to arrange for your tester, Mr. Ward, to come down and look at my car. Unfortunately on that afternoon I had three or four people to see simultaneously, and did not have time to go thoroughly into matters with him. The detonation that I was worrying about is one that continues up to over 3,000 revolutions. For example, at speeds between 60 and 70 m.p.h. on top, it is still necessary to keep the throttle to not much more than half if detonation is to be avoided. Alternatively, to prevent it by retarding the ignition still involves bringing the ignition lever back about a third of the way, with an appreciable reduction in power. I am having the plugs examined to make sure that the cause is not brought about by a little projection becoming incandescent. I should observe here that pinking does not occur until the thermometer is showing above 75°, and it is quite possible that when Mr. Ward tried the car, which was only on a local run, this temperature was not exceeded. I have also noticed that when the car has had a good fast run of something over 50 miles, the tendency to detonate is very much reduced, irrespective of the fact that the temperature will be at the usual thermostat point, which in the case of my car, is between 82 and 85°. P.T.O. | ||