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).
Fuel detonation tests and the development of a vernier control system to counteract it.
| Identifier | ExFiles\Box 168\3\ img186 | |
| Date | 1st June 1939 | |
| -2- (2) To find the actual variation in detonation on different fuels, and amount of retard necessary to eliminate it. (3) To adapt the governor curve to suit a vernier control. (4) To measure the loss of power due to retarding to stop detonation. (5) To make the necessary recommendations for production. The results were as follows:- (1) The method used was an over-riding hand control calibrated in degrees, so that a correction could be made at each speed to the actual governor curve being tested, and the result plotted. The next curve tried in each case was made to the last result. With the best curve for Ethyl there was a loss of performance when retarded for Redline No.1. (2) Fig. II shows the detonation curves taken with the governor locked and the calibrated hand control. They represent results with Discol, Ethyl, Shell No.1 and Redline No.1 also variations with water and 38% Zero in the radiator. They include results of different operators and different weather conditions and the object of grouping them together indiscriminately was to discover the actual range over which results had to be obtained and the general trend of the curves. (3) It was clear by now that a vernier control was required to cover such a range and the problem was to arrive at a curve which when retarded for the worst No.1 petrol had sufficient advance at the top end and yet did not bring in high speed detonation when advanced for best performance on Ethyl or Discol. The curve arrived at, first by deduction and developed by trial and error is shown on Fig. II at three typical settings of the vernier. | ||