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).
Technical memo discussing water boiling and cooling system improvements for the 40/50 and Goshawk models.
| Identifier | WestWitteringFiles\K\August1923\ Scan3 | |
| Date | 10th August 1923 | |
| TO HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} COPIES TO SJ. BJ. PN.{Mr Northey} OY. H.{Arthur M. Hanbury - Head Complaints} ORIGINAL R6/M10.8.23. RE. WATER BOILING. 40/50 & GOSHAWK. X1751 X.766 Y3499 Y4240 (1) The fan seems to be the most important feature: to be very efficient it should in all cases be as large as possible, even to the last .1 of an inch. It should run reasonably fast but not so fast as to be unreliable and noisey, and destructive to the belt. (2) The bonnet louvres or shutters should not be abandoned and should be fitted if No. 1. fails. (3) The 40/50 ventilated underguards must be very good and should be retained, and tested if these are as good as No.2. (For clearness always use the term "Bonnet" or "Radiator" shutters.) (4) Mr. Sidney's report is most kind and reasonable, and we ought to know more exactly what are our limitations as to speed and temperature. His suggestion of a thicker radiator, i.e. fore and aft, has been tried and not found any advantage, because the air current is reduced and it's temperature increased, resulting in making the floorboards hotter. (5) The gearbox undersheet can (according to Springfield) be shortened by 17" without disadvantage. (6) The only alteration to dimensions is to increase the face area preferably in height a slight amount, with increased size of fan (should be tried.) (7) Have we thoroughly thrashed out the feature of loss of water by water being thrown out, whereas we ought to only lose water in the form of steam after the first initial quantity? (8) State how much is due to expansion of water, and how much due to displacement of water by steam in cavities in upper part of cylinders? (9) On some of the 20.HP. cars we have a thermostat chamber which may help as a separator. Does it? (But no separator can do any good to prevent or reduce (7).) (10) The principle of separating steam from water is usually a whirl chamber the water passing away over the edges and the steam coming away at the centre (see sketch.) Has such a scheme been tried? (11) We should all realise that overheating of the cooling water will always occur under suitable circumstances if the engine is kept pulling hard at slow speed with full throttle. Fortunately or unfortunately this is what our engines are especially capable of doing. (12) We hope we are sending out Goshawks with radiator shutters incorporated with the radiator and not as separate units. I would like to point out that the by-pass radiator is the coolest proposition for floorboards so that the cooling air under the bonnet can be kept at the lowest temperature possible. This condition does not seem a disadvantage in summer. R.{Sir Henry Royce} AR | ||