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).
Tests for self-ignition temperatures of different fuels like petrol, benzol, and Discoll.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan216 | |
| Date | 8th June 1926 guessed | |
| contd :- -3- of the fuel used, or rather by the self ignition tempera- ture of that fuel. It was proved by repeating the previous test that self ignition would occur with petrol, benzol or discoll (an alcohol mixture) but owing to the difference between their self ignition temperatures it was imagined that for a certain condition of speed and valve temperature at which petrol would just self ignite, probably benzol would be free from the trouble. Figures by Ricardo in the "Empire Motor Fuels Committee Report" give the self ignition temperatures of petrol, determined by adiabatic compression with air, as 367°C, Benzol 419°C, and members of the alcohol group from 457°C to 514°C. The following test was therefore made to shew the effect of the fuel. Unfortunately all the available 'Discoll' fuel was used up in the previous experiment and we therefore had ordinary Shell Mex petrol and Benzol at our disposal. The engine was run at a speed of 3000 r.p.m. giving 58 HP. for three minutes, after which time the valves assumed a constant temperature. It was then throttled down to 500 r.p.m. light running for a short period and the ignition switched off. The slow running period was increased until no self ignition resulted on switching off. This test was conducted with both petrol and benzol and the slow running period was simply another, though probably somewhat crude, method of expressing the minimum valve temperature at which self ignition would occur. The longer the period - within limits - the cooler would be the valves. contd :- | ||