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).
Visit to Dennis Bros. to inspect the performance of A.C.6 connecting rod bearings.
| Identifier | ExFiles\Box 115\5\ scan0059 | |
| Date | 28th June 1938 | |
| 28.6.38. REPORT ON VISIT TO MESSRS. DENNIS BROS. This visit was made to the Dennis Works to inspect the set of A.C.6 connecting rod bearings supplied to them last December. The Writer interviewed Mr. Milne of the Dennis Co. and Messrs. Blackith & Noble of Messrs. Wellworthys were also present. The bearings have so far run for 310 hours on the test bed, the engine developing 130 B.M.E.P., originally the engine was supercharged, but recently they have removed the supercharger but have maintained the M.E.P. by cleaning up the ports and reducing the size of their valves. The bearings on being stripped were found to be in good condition as far as hammering was concerned, there being no movement of the bearings in their housings, the surface, however, was badly scratched and marked, and, in general, looked as though a considerable amount of dirt had entered the bearings. Mr. Milne admitted that they might not have been as careful in cleaning as they might have been, but pointed out that the bearings had been pulled out of the engine several times for inspection of pistons and rings. One bearing showed signs of having had some foreign matter trapped between the back of the bearing and the housing. Dennis Bros. themselves are very pleased with the results obtained and are now pinning their faith to the A.C. alloys, they admitted yesterday that it was the best material they have tried so far. They are very anxious to get hold of some material for main bearings, and we have agreed that Messrs. Wellworthy should supply them with A.C.9 alloy. The Writer pointed out to Mr. Milne the importance of good filtration and of cleaning engine parts during the erecting period, and suggested that they centrifugally clean their oil continuously on their line of test beds, and that they adopt the by-pass type of filter. The Writer has also written to Mr. Milne stressing this point. Mr. Milne also showed the Writer a scheme whereby they are trying to centrifuge the oil in the engine itself; the arrangement looked quite neat and consisted of a "Lolos" filter rotated by means of a gear drive. Milne anticipates a certain amount of trouble with this arrangement but thinks | ||