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).
The performance tests of split type pistons, noting some slight knocking issues.
| Identifier | ExFiles\Box 171\3\ img022 | |
| Date | 18th November 1919 | |
| BN.{W.O. Bentley / Mr Barrington} from EP.{G. Eric Platford - Chief Quality Engineer} Copy to BY.{R.W. Bailey - Chief Engineer} " " EH. " " WOR.{Arthur Wormald - General Works Manager} EP{G. Eric Platford - Chief Quality Engineer}9/F18.11.19. RE TESTS OF SPLIT TYPE PISTONS. Two tests of the latest type split pistons have been run on test cars, each set having run a distance of about 1,500 miles. They have been dismantled and examined on two occasions, and have found to be quite satisfactory. No trouble has been experienced with these pistons during the test, and they can be considered quite free from piston knocks, except that there are signs of *a very slight knock when starting up cold, but this disappears after running about half a minute. They are certainly a great advantage in this respect as compared with the plain type pistons. *These knocks have developed with with running. They have been well thrashed on the dynamometer, and have had some continuous hard running on the road, but no trouble has been experienced with seizing up or pistons knocks. Both sets are of the low compression type. A slight elusive knock has been noticed during the latter part of the above run, but this does not appear to be a piston knock, as it cannot be cured in the same way as piston knocks are overcome. It was only a slight knock, and was not there continually, only appearing occasionally when running light with the engine very hot, and had the same sym-toms as a gudgeon pin knock. The matter has been brought to the attention of Mr. Hives, and we are now investigating this point. The knock referred to I think is rather an impor-tant point, as it appears to have developed on these two sets of pistons. There are also signs of a similar knock taking place on a set of pistons fitted to one of the Trials cars, 19-LW. EP.{G. Eric Platford - Chief Quality Engineer} | ||