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).
Testing alternative materials, such as synthetic rubber and oiled silk, for fuel pump diaphragms to resist alcohol-based fuels.
| Identifier | ExFiles\Box 149\4\ scan0231 | |
| Date | 8th April 1937 | |
| -2- In the cases (1) and (3) the cars had been running on Alcohol fuels for half the time which we know attacks the material and would shorten the life. When I visited the S.U.Co. yesterday they are at last showing signs of attacking the diaphragm problem seriously, and have got the co-operation of the Dunlop Rubber Co. the I.C.I. and the Power Petrol Co. The latter particularly as the S.U.Co. had threatened to label their pumps as unsuitable for Discol when in all probability the A.C. Co. would follow suit, and they have placed their fleet of 100 cars at the S.U.Co.'s disposal to test diaphragms as well as introducing them to various makers of materials, that they have found necessary on the hoses for discol pumps. The most promising material so far tests is GACO, a synthetic rubber, but this is made in Germany and supplies are difficult to obtain. The Dunlop Rubber Company have submitted samples of synthetic rubber-like material of a similar nature known as Neoprene, also fabric impregnated with Neoprene, of which we have a sample to test. For the present the S.U. Co. have been testing oiled silk which withstands hot petrol but is not proof against discol. They have been unable to shrink it and it has withstood 3 weeks endurance running hot with no detrimental effects. Two layers of oiled silk are placed between the G.5. material. We have inserted it between G.5. material that is porous and it has cured the trouble (22.G.V. and 32.EX. high pressure pump) As to the ultimate life of a diaphragm with oiled silk, we have not yet completed any tests and only tests on the car will be of any real value as our endurance tests here have already shown that they are not comparable with results on the chassis. The S.U. Co. are in a position to supply oiled silk immediately and are going to do so on their standard production pumps. In view of these results we can see no disadvantage and the hope of an improvement in the life of the diaphragm. We therefore suggest that the original intention to change all diaphragms after 15,000 miles should be changed to 10,000 miles and then replaced with G.5. and oiled silk and it should go on Production immediately we have concluded definite tests for shrinkage. Samples are being boiled in petrol in the Laboratory here to make doubly sure against shrinkage. RM{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems} | ||