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).
Valve friction, bounce, and a new apparatus for recording valve motion.
| Identifier | ExFiles\Box 43\3\ Scan106 | |
| Date | 4th January 1927 guessed | |
| contd :- -2- The above factors might explain some of the difference between the behaviour of the inlet and exhaust valves. We have taken some readings of the friction existing during the opening and closing of the valves due to the guides and rockers. The test was made by attaching an arm to the rocker from which different loads could be suspended and noting the opening of the valve for each load by a micrometer depth gauge. The appended curves shew the results from five valves and it will be seen how this friction further discounts the spring pressure during the closing period. Previously all our observations of valve bounce have been made by means of the oscilloscope but now we are fitting up a simple apparatus to give us a permanent record of the valve motion. Briefly this consists of a disc rotating with the camshaft and a small scriber attached to the valve washer which when the disc is brought into contact with it - being previously covered with whitening - will give a polar diagram of the valve motion (See appended sketch). With this apparatus we hope to be able to study more closely the valve motion during bounce and see at what part it actually leaves the cam and the extent of the bounce. We should have some results in a few days. HS{Lord Ernest Hives - Chair}/A.C.Lovesey. | ||