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).
Corrosion tests in cooling systems, detailing trials on a new engine and a corrosion inhibitor.
| Identifier | ExFiles\Box 150\3\ scan0361 | |
| Date | 21th February 1938 | |
| -2- The same water was retained in the system throughout each test, fresh tap water being used at the commencement of each new test. In addition to these rig tests observations have also been made of corrosion in various experimental cars. It was immediately noticed that whereas the cooling systems of the first Ph.III cars suffering from this corrosion trouble were choked with sediment which was carried round by the coolant, no such sediment was evident in the system during or at the termination of either of the above mentioned rig tests. Further, the water was only slightly discoloured in the test with the iron hotspot box in circuit and no choking whatever of the radiator matrix occured. A new engine was then fitted to the rig, on which all aluminium pieces in contact with the coolant had been anodically oxidised prior to being doped with linseed oil. Further, care was taken where ever possible to wipe the surplus linseed oil off the surfaces during the doping process. This engine was then run for a similar period and results are shown on Sheet (1) - Test (3). It was intended to obtain two comparative photographs, one at the end of Test (2), the other at the end of Test (3) indicating the relative corrosion which had taken place - unfortunately this was rendered impossible by the fact that near the end of Test (3) the old type oil cooler fitted to the engine (to heat the timing gear oil) burst and flooded the water system with oil. The coating of engine oil rendered the taking of any comparative photographs useless. It did not, however, after careful washing, prevent us from visually observing the corrosion which had taken place. This is commented on, see attached sheet. In addition to above tests we had also tried a corrosion inhibitor known as "No-Co-Ro{C. C. Rose - Export Manager}" marketed by Messrs. Newton & Chambers Ltd. This liquid looks and smells like concentrated Izal disinfectant and is claimed by them to greatly reduce iron corrosion. We have a number of cars running with this inhibitor in the water system (including 20.G.VI and 8.B.IV in France) and 32-EX was sent out on its last 15,000 miles test with this inhibitor originally in its water system, but had none added subsequently. Formerly Messrs. Newton & Chambers claimed that this inhibitor need only be added when the engine was new and not afterwards. They are now of the opinion that it needs replenishing from time to time. | ||