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).
Laboratory report on the analysis of two samples of Castrol oil, one unused and one used.
| Identifier | ExFiles\Box 76\3\ scan0124 | |
| Date | 19th February 1920 | |
| R.R 285A (100 T) (S.G 643, 19-2-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2618 EP.{G. Eric Platford - Chief Quality Engineer} c to EH. H19/EBL7620. Laboratory. Re 2 samples of Castrol. One lot unused from cask, the other in a frothy condition and black after having been in use. It was found on test that the acidity of the two oils was higher than usual, viz 1.7%, and it appears likely that this is the cause of the trouble experienced, since finely divided carbon and metallic powder (in the presence of water) are likely to be acted on to some extent and thus produce frothing, especially if the oil becomes rather warmer than usual. The action need not necessarily lead to the neutralization of the acid present, so that the trouble may continue. The dirty oil was found to contain some moisture but otherwise the two oils were normal with respect to castor oil present and mineral oil; these being 82% and 17% respectively on the dry oils. The usual acidity of castrol is about .5%. Wdh | ||