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).
Tabular comparison of engine performance at 50°C and 100°C water temperatures.
| Identifier | ExFiles\Box 147\5\ scan0055 | |
| Date | 21th August 1915 guessed | |
| | | Water Temp. | | |---|---|---| | Conditions. | 50°C | 100°C | | Consumption M.P.G. | 14. Mixture adjusted to suit. | 15 1/4. Mixture adjusted to suit. | | Pints per HP hour at 1000 r.p.m. | .86 | .75 | | HP on the Test Plate. | | | | 500 revs. | 23.3 | 22.7 | | 1000 " | 42.9 | 43.3 | | 1500 " | 56.25 | 57.25 | | 2000 " | 60.8 | 62.0 | | Power of engine on the road. | When the water is at this temperature on the road the whole of the working parts are correspondingly cool, the engine is very feeble, much worse than is shown on the test plate where the water only is at 50°C. | Very good, but I think one can appreciate the loss in power at low speeds, a lot more gas seems to leak past the piston. | | Carburetter. | We get twice as much petrol collecting in the pipe and throttle than at 100°C. We get misfires due to richness on Nos 3 & 4 cylinders. It altogether upsets the automatic working of our carburetter. | On the road we cannot appreciate any defects in the carburetter, there is a little petrol collects but it does not cause any harm. | | Detonations. | Nearly impossible to get them. | Bad. It is better if the water is at 75°C. | | Clapping of the piston. | This is always worse at the low temperature. | --- | Footer Text: E K's 32 v (to H) (A'A' 363. 2.14) C 022? | ||