Analysis of engine performance, detonation, and fuel volatility under different heating and fuel conditions.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan96 | |
| Date | 14th January 1926 guessed | |
| contd :- -16- in which the outlet pipe from the hot spot exhausted into the atmosphere to give us the maximum possible temperature, the ignition being then adjusted until there was just no audible detonation. This was repeated with a cold hot spot when it was found that the respective spark positions were 22º B.T.C. with heat, and 25º B.T.C. without heat - a difference of only 3º. When operating with the ignition giving maximum power we could not appreciate any difference in the intensity of detonation between the hot and cold conditions. Accelerating under load from a low speed was accompanied by severe detonations but no difference whatever could be detected in this respect with either hot or cold hot spot. INFLUENCE OF THE VOLATILITY OF THE FUEL ON TIME TAKEN FOR ENGINE TO OPERATE EVENLY. The volatility of the fuel naturally has considerable influence on the time taken before the motor will operate evenly on all cylinders when started up from cold. The fuel we employed for these tests (Shell Mex) was very poor in this respect but was useful in showing more clearly the difference between the heating systems. With Benzol 50/50 mixture - which has a higher volatility value than petrol - the all round operation of the engine was improved and differences existing between each system were not so marked as when using our standard testing fuel. The following curve is of interest in showing the temperature drop in the induction pipe and affords a comparison of the relative volatility of the two fuels. contd :- | ||
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).