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).
Exhaust valve failure on a Phantom II during an endurance run.
| Identifier | ExFiles\Box 14\6\ Scan259 | |
| Date | 2nd August 1932 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} 87230 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}9/ATL.2.8.32. FAILURE OF EXHAUST VALVE - PHANTOM II We have recently had an exhaust valve failure on the Phantom II. The exhaust valves had done a considerable amount of running at a maximum of 87 lbs. with the valve closed and was doing an endurance run at 93 lbs with the valve closed when the failure occurred. The object of the run was to prove out some springs which showed slightly less signs of surging than those we ran on the 10,000 mile test. We think that the failure definitely shows that we are getting near the limit of what we can do with the 40/50 exhaust valves unless we salt-cool them. One would normally attribute the failure to allowing the valve to bounce and it may be that these valves have bounced momentarily though we do not believe so. It must be borne in mind that a similar valve has run a 10,000 mile test without any trouble. We have done a considerable amount of work with this valve on the test bed with the silencer fitted and we do know that the exhaust back pressure has a disastrous effect on the valves, also that the car running in France had a freer exhaust system. Summarising the failure, we do not think we can ask you for any alteration in design until we have a reproduction of the trouble. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} P.S. We hand you the valve herewith. | ||