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).
Summary and proposal regarding cooling improvements for the Phantom III engine by modifying the exhaust port water jackets.
| Identifier | ExFiles\Box 94\3\ scan0188 | |
| Date | 22th April 1937 | |
| -2- Rm{William Robotham - Chief Engineer}/Std.8/JH.22.4.37. Sheet (2) shows curves of total heat to water for std. Phantom III engine, total heat to water for same engine without exhaust port water jackets, and percentage increase in total water heat due to using water jacketted exhaust ports. From a study of these it will be seen that the heat picked up in the exhaust jackets increases the total heat by approx. 10 - 12% at low speeds and 16% at top speeds, under full throttle conditions. Summary. In view of the fact that we are very definitely on the border line as regard cooling on the Phantom III car, any practicable scheme which is likely to improve the cooling should be tried. It is seen from above figures that dispensing with water jacketting of the exhaust ports would reduce the maximum heat to be dissipated by approximately 12 - 16% and also reduce the complication and cost of the cylinder head casting. We think that in view of this a design should be produced as soon as possible for a cylinder head and exhaust manifold with the water jacketting deleted. We are aware that there is the possibility of overheating the sparking plug leads etc. but think that the question of this occurring can be settled by experiment. It should be possible to improve matters in this direction by providing recesses in the external surface of the head to accomodate the wires. If it is decided to design such a head we think that it should also incorporate (1) front end outlets instead of top rails, (2) thermometer pocket at front end of 'a' side head instead of rear end of 'b' side head, as mentioned in report Rm{William Robotham - Chief Engineer}/Std.15/AP.2.4.37. Rm{William Robotham - Chief Engineer}/Std. | ||