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 adoption of new pistons and the use of scraper rings in engines.
| Identifier | Morton\M22\ img009 | |
| Date | 12th May 1915 | |
| 7CA o 49 GB PISTONS, RINGS OIL CONTROL COPY. RM{William Robotham - Chief Engineer}/65 L140 Issues filed in X 1176 & 1359 To Wor.{Arthur Wormald - General Works Manager} for EH. } from R.{Sir Henry Royce} " E.{Mr Elliott - Chief Engineer} Copy to J.{Mr Johnson W.M.} " " EP{G. Eric Platford - Chief Quality Engineer} " " Na.{Mr Nadin} R6/IB12515. May 12th. 1915. Re Pistons. ---------- According to Mr Hives' report, he has passed the pistons which are at present fitted to car 7CA. As these pistons have been through many trials, it is quite evident that it would be safe to adopt them, which I hope Mr Elliott will please do without delay for all purposes of repairs and new engines. Mr Hives in his report, does not seem to state definitely whether he would expect better results from these scraper ring pistons, but as they were originally schemed to replace the idea of fitting tight skirts round the bottom of the pistons (which I consider are dangerous), I presume he thinks they are as good as such pistons, and much more satisfactory in many other ways. You will remember too, that in fitting the scraper ring pistons, we have always removed all the baffles, but when the scraper ring is low down, it is necessary to alter the extra lubrication to fall on to the cranks, instead of through the cylinder sides. So that engines which cannot be so altered should be fitted with the same type of piston (diagonal webbed) but with the bottom of the upper three rings made into a scraper ring. | ||