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).
Investigation into a choked radiator causing overheating and water loss on a customer's car, including the diagnosis and rectification work.
| Identifier | ExFiles\Box 47\2\ Scan175 | |
| Date | 25th November 1929 | |
| X.4117. To Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. WOr.{Arthur Wormald - General Works Manager} c. Hn.{F. C. Honeyman - Retail orders} c. By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rml/AD25.11.29. 61-CL. SHORT'S CAR. We have now finished work on this car and have sent it over to the Repair Dept. It had the worst example of choked radiator we have ever seen. It was so bad that we were unable to clean it out by the normal works process. While we have now examined the matrix in the laboratory, and while it is full of the usual deposit, we also found traces of other substances which led us to suppose that some rather peculiar water had been used. This supposition is strengthened by the fact that a number of the tubes are corroded. From the length of time the car has been in service we should not expect this. We have fitted a new radiator to the car having 1 1/4 mm. gaps between the tubes, and thoroughly scoured out the cylinder block and head, from which we obtained a considerable quantity of corrosive deposit. The point that we really wanted to investigate on the car, is that Mr. Short had put a restriction in the top connection from the cylinder head to the radiator in order to prevent loss of water at high speeds. We find that Mr. Short was perfectly justified in what he had done, because his radiator was so restricted in the top tubes that the water pump was drawing water from the centre of the matrix and creating a vacuum there. The water thus obtained was being driven round to the top of the radiator and building up there, causing loss of water every time the car was run at high speeds. This loss of water aggravated the overheating trouble caused by the choked radiator. Having changed the radiator we found it was still possible to lose a small quantity of water when the car was driven at maximum engine speed, and in order to overcome this we changed the water pump. This reduced the trouble, and with Mr. Short's water pump we have been able to reproduce the phenomenon on another car. We therefore do not wish to keep Mr. Short's car any longer. We must point out however, that if the car is driven all out on 3rd gear, it is still possible to lose a trace of water through such freak driving. | ||