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).
Analysis of a radiator cooling phenomenon, including experimental reproduction of the fault and a comparison with Chrysler radiator designs.
| Identifier | WestWitteringFiles\U\January1930-April1930\ Scan028 | |
| Date | 10th January 1930 | |
| -4- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}S/MJ.10.1.30. A phenomenon we observed on Mr. Short's car, an F.2B series with choked radiator, was that water was thrown out of the steam pipes when the engine was "reved" up even with the water cold. His radiator was a particularly bad case of choking up, but we have been able to reproduce the same trouble by artificially obstructing the top row of tubes on one of our own cars. Apparently the pump is able to create a partial vacuum in the centre of the radiator and push the excess of water so obtained into the top tank where there is no room for it. A reduction in pump delivery reduces this trouble slightly but is not of much interest as for the trouble to occur at all the radiator must be in a hopeless condition. In order to avoid loss of water by expansion (which is very rapid above 90°C) and incipient boiling, we have brought the red lamp in at 92 1/2°C. We could with advantage have slightly more top tank capacity to deal with this now that we carry more water owing to the larger spaces between the tubes. The Chrysler evidently attach more importance to top tank capacity as they have an extension at the rear of the top tank (see sketch). We attach a list of radiator weights. The Chrysler succeed in cooling their car with a very small matrix, but nevertheless our own weights seem rather great. E has suggested making our shutters in a thinner gauge stainless at present they weigh 18 1/2 lbs. on Phantom 11. Summarising the results. (1) Reducing the water pump delivery does not seem as if it would help us. | ||