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).
Redesign of the P.2 piston by increasing its length and testing a new design.
Identifier | ExFiles\Box 15\3\ Scan050 | |
Date | 10th January 1931 | |
BY.{R.W. Bailey - Chief Engineer} FROM E.{Mr Elliott - Chief Engineer} X7040 E5/M10.1.31. C. to HS.{Lord Ernest Hives - Chair} MX.{John H Maddocks - Chief Proving Officer} P. 2. PISTONS. When in Derby I was present at a discussion with HS.{Lord Ernest Hives - Chair} and MX.{John H Maddocks - Chief Proving Officer} at which some outline drawings were exhibited shewing an interesting comparison between various pistons. The conclusion arrived at was that our P. 2. piston is too short compared with the 25HP., and probably the trouble at present being experienced with cold taps is due to this apparent defect in its proportions. A.P. 1. piston of RRAI. pattern was exhibited and this had a much longer skirt than our P. 2. and represents the result that America have arrived at after various experiences and experiments. We propose to try P. 2. piston with .6 added to the length and at the same time a slight reduction in the clearance of the skirt which may be permissible now that we have largely overcome our distortion troubles in the cylinder bore. At the same time we should also like to try a more rapid expansion of the width of bedding of the cylinder skirt, progressing downwards from the oil collecting groove. It is suggested that 6 sets should be instructed and sent through on production for MX.{John H Maddocks - Chief Proving Officer} to observe. To avoid unduly increasing the weight the added portion might be counterbored parallel to say .1 or slightly less thickness. E | ||