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).
Tests and apparatus for measuring gas leakage past pistons.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan056 | |
| Date | 12th October 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} EY. ORIGINAL Hs{Lord Ernest Hives - Chair}/ACL1/LG12.10.26. TESTS ON GAS LEAKAGE PAST PISTONS. X858 X8040 At various times we have encountered troubles on our different engines which we have associated with gas leakage past the pistons, but up to the present have not had any direct means of ascertaining this. Such troubles as the 'chirping' noise from some 20 HP. cylinders and carbonising of piston rings in the grooves on both car and aero engines have thought to be in some way connected with gas leakage, while the tendency of some cars to give silencer explosions even with a well fitting throttle could possibly be caused by upward leakage past the pistons. Consequently we have devised an apparatus which enables us to determine the gas leakage during the compression stroke and see how this is influenced by vario-us factors. The following is a brief description of the apparatus - diagram of apparatus attached to Hsl/LG6.10.26. The cylinder to be tested has the push rods removed so that when charged with air at atmospheric pressure it will continually compress and expand that air. A part of this air will naturally be lost past the piston and result in the pressure at the end of expansion being below atmospheric. This loss is supplied by air which enters through a light automatic non-return valve immediately the pressure in the cylinder falls below that outside. contd :- | ||