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).
Conclusions from tests on an engine's cooling system, focusing on water flow and cylinder head temperatures.
| Identifier | ExFiles\Box 94\3\ scan0178 | |
| Date | 22th April 1937 | |
| -2- Unfortunately this method increases the hydraulic resistance of the system and so lowers the engine water flow, but pipe sizes etc. were kept as large as possible and a double outlet from second radiator was used to minimise this effect. Local cylinder head temperature measurements were made by means of thermo couples using the external contact method of reading. The temperature rise across the engine and hence the deduced water flow were measured by means of glass thermometers, but the results obtained are not entirely consistent and indicate that this method of measurement is not very accurate. Conclusions from Tests. (1) Heat to water curve - Sheet (1). (2) Local cylinder head temperatures under standard conditions as shown on sheet (2) indicate bad steam pocketting in the cylinder head. (3) Local cylinder head temperatures with end outlets as shown on sheet (2) indicate improved conditions as regards local temp. variation etc., but thermometer at the rear of cylinder head gives a considerably higher reading than the outlet water temp. (4) Local cylinder head temperatures with end outlets and feed to rear of head from oil cooler box indicate improvement as regards local temperature variation - about the same as (3) - but the rear cylinder head thermometer reading is now lower than the outlet temperature. (5) Water flows with all three systems of flow ( as mentioned in (2), (3) and (4) are practically the same. (6) The effect of the gauze filter (see Sheet (4)) on the water flow is small enough to be neglected in view of the desirability of this feature. (7) The water flows indicated in these tests are below those under road conditions, owing to the hydraulic resistance of the cooling system - separate tests will be carried out to determine the actual water flows which are obtained in the car. (8) No trouble was experienced during the pressure cooled run - the local temperature chart (Sheet 5) seems to indicate that the variations of temp. throughout the cyl. heads are no worse than at lower coolant temperatures. continued | ||