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).
Piston design issues, cooling, and ring configurations for two-stroke and four-stroke engines.
| Identifier | ExFiles\Box 86\2\ scan0301 | |
| Date | 22th November 1934 | |
| To H.{Arthur M. Hanbury - Head Complaints} Copy to Wer. Hs.{Lord Ernest Hives - Chair} RHC.{R. H. Coverley - Production Engineer} BY.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Wd{Mr Wood/Mr Whitehead} E/PSN.1/WN.22/11/34. PISTONS. During the course of our investigation into the piston problem on the Two-stroke engine a number of points have arisen which are of more immediate interest in connection with high temperature cooling on Four-stroke engines. A piston has already been designed and instructed to LeC 4150 in which the cooling ribs are carried right down to the thrust faces. The object of this is to conduct some of the heat from the head to the thrust faces and hence to the coolant, and also to provide increased fin area for underhead cooling. Another piston is now being designed in which the top lands bed on the thrust sides, with the object of improving the heat flow from the piston crown to the coolant. It is proposed to keep the intermediate lands out of contact with the cylinder walls as it is doubtful whether they are mechanically strong enough to stand up to the increased loading which would be imposed. Bristols use only two compression rings and if we could get away with the same number it would enable us to strengthen up the intermediate lands and let the piston bed on them, with consequent further improved heat flow from the piston. In order to test out the possibilities of using only two compression rings we should be pleased if Hs{Lord Ernest Hives - Chair}/Wd{Mr Wood/Mr Whitehead} would run some tests as soon as possible with the bottom compression ring removed on a standard piston of the type having two scraper rings. A new type of scraper ring has been designed for the Kestrel and P.V.12 to LeCs 4199 and 4201, which is similar to that used on the Wright Cyclone engine. Three sets for both Kestrel and P.V.12 have already been ordered and should soon be available for testing. E/PSN. | ||