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 erosion of valve seats on Phantom and aero engines.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan009 | |
| Date | 12th April 1926 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to BJ. RG.{Mr Rowledge} c. to BY.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}3/LG12.4.26. EROSION OF VALVE SEATS. X8060 73869 We have found the valve seats on the Phantom engine which was fitted to 8-EX chassis which ran 10,000 miles in France have similar signs of erosion that is troubling us on aero engines. The exhaust valve seats we should say have sunk about .025". Although they are not as bad as the examples we have seen on the aero engine, the fault appears to be the same. We have the impression that the seats are worn away by an abrasive action caused by the scale formed on the exhaust valve and slight twisting of the valve when closing due to the spring. The fact that the seats which have worn show no signs of over-heating, burning or cutting, gives us this impression. We have operated valves in the cylinder by means of a belt. On the valves we put a little abrasive paste. We found that we could get the seats to wear in a similar manner; the valves wore at about the same rate. On the engine it may happen that the exhaust valve is protected by a hard scale. We have heard that the R.A.E. had a similar experience and it has only occurred in cases where a high chromium valve was used. It would appear to be a very useful experiment to try different materials for the valve seats. Hs.{Lord Ernest Hives - Chair} | ||