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 the corrosion of aluminium components in the Phantom III engine's cooling system.
| Identifier | ExFiles\Box 150\3\ scan0360 | |
| Date | 21th February 1938 | |
| spare. 1280 also 340 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Std. c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. El. c. RHC.{R. H. Coverley - Production Engineer} P.III - CORROSION OF ALUMINIUM CYLINDER HEAD, CRANKCASE, WATER PUMP COVER ETC. In view of the trouble which has been experienced on Ph.III cars with choking of the radiator matrix with corrosion product from the engine, we have endeavoured to find means of reducing this corrosion. The corrosion product when analysed has always proved to be a mixture of aluminium and iron corrosion products in approximately even proportions. It has been thought that the excessive corrosion which has taken place on many Ph.III cars is due primarily to the presence of iron (in the form of the hot spot box) in the cooling system, contributing factor being frequent change of water due to water loss by spilling caused by steam valve leakage. Our Laboratory inform us that the best way of reducing this corrosion is by - (a) eliminating iron from the water system. (b) Anodically oxidising all the aluminium in contact with water prior to doping with linseed oil. In view of the difficulty of controlling tests over a long period on experimental cars running, we endeavoured to have conditions under control by running tests on a P.III rig engine which is also used for timing gear endurance and water pump and fan tests. This engine was driven by an electric motor instead of under its own power and was coupled to a radiator as near as possible as on a car and provided with a means of heating the circulating water. The engine (fitted with a new scrap crankcase) was run for two consecutive tests of 100 hours running each, one with, and one without the old standard cast iron hot spot box fitted. Estimation of corrosion was necessarily only visual and results of these tests are shown on Sheet (1) attached. Attached also is a photograph of the inside of the crankcase water at the end of these two tests. | ||