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 showing the effect of water temperature on fuel consumption and engine performance.
| Identifier | ExFiles\Box 147\5\ scan0053 | |
| Date | 16th January 1914 | |
| From Exp. Dept. Copies for: J.{Mr Johnson W.M.} R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer} Na.{Mr Nadin} Wor{Arthur Wormald - General Works Manager}/EH3/L16114. January 16th. 1914. Tests showing the effect of the Water temperature on Consumption. X. 459. Our tests show that it is more economical and the cars run much better all round when the water is kept at anything over 75°C, there is only one disadvantage and that is, when the water is about boiling an engine is much more liable to detonate. Attached is tabulated the difference working at 50°C and 100°C. With the atmospheric temperature at Zero the temperature of the water in a standard car running light at 20 to 25 m.p.h. is 48°C to 52°C. When the water is at this temperature the car is very nasty to drive, there is very little power in the engine and the mixture must be put over strong to get any speed, but if the car is pulling at low speeds the engine misfires due to too rich a mixture in Nos. 3 & 4 cylinders. With our type of induction system it is quite satisfactory as long as the petrol is properly atomised, but if the petrol is carried into the pipe as a liquid then the nearest cylinders must naturally get the most petrol and those farthest away are starved; we cannot put this down to the shape of the induction pipe because we could get the same thing on the marine engine when the engine was cold. | ||