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).
Thermal lock seizure tests comparing R.R.56 alloy and cast iron exhaust valve guides.
| Identifier | ExFiles\Box 10\3\ 03-page100 | |
| Date | 15th September 1937 | |
| TEST ON THERMAL LOCK EXHAUST VALVE GUIDES Tests have been carried out on two Exhaust Valve Guides, one made of R.R.56 with a .002" clearance in the bore, and the other made of cast iron with a .00125" clearance in the bore. The object of the test was to find the load required to cause seizure. A head with a standard valve and valve guide was mounted on a test rig. The valve was loaded by means of a spring balance so that the load could be read directly. Heat was applied externally to the valve guide and the valve was reciprocated. With the cast iron valve guide the valve seized at 220°C with a load of 14 lbs after 25 minutes. With the R.R.56 valve guide the valve did not seize up to a temperature of 300°C when the test was discontinued. The heat was not passed through the valve as this would have been more difficult, but the test demonstrates that the R.R.56 guide is better. for DEVELOPMENT | ||