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).
Leaking exhaust valves in a standard Bentley head and future work on ramp and modified Bentley heads.
| Identifier | ExFiles\Box 133\2\ scan0083 | |
| Date | 26th May 1944 guessed | |
| (7) LEAKING EXHAUST VALVE (Standard Bentley Head). We have experienced three more instances of a leaking exhaust valve on the standard head, apparently due to hammering of the seat. This trouble occurs after the engine has cooled down, when it is found that the exhaust valve is not seating properly and will not hold compression. So long as the unit is kept hot the trouble is not apparent. This trouble occurs only on the standard head. ------------- FUTURE WORK. No.2 Ramp Head. This head is to be run at increased compression ratio, naturally aspirated and supercharged, with a view to obtaining the maximum power output irrespective of valve timing overlap. Modified Bentley Head. This head has improved trepanning around the inlet valve and will take an inlet valve .150" larger than standard. Tests are in hand on the effect of variations in valve size on performance. ------------- Wd.{Mr Wood/Mr Whitehead} Hs{Lord Ernest Hives - Chair}/Wd{Mr Wood/Mr Whitehead}/CHP. | ||