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).
High-speed endurance test of pistons, detailing an exhaust valve failure and subsequent analysis.
| Identifier | ExFiles\Box 88\4\ scan0030 | |
| Date | 23th September 1933 | |
| FILES: PISTONS. UNIT.C.XI. EB.495 Piston - A/P 404. Die cast. Ex.11480 Piston grinding. EB.514 Scraper rings (.085 oil groove). High speed endurance has been carried out on the above unit, similar to that of Aug. 26 on C.XIII. After 7½ hrs. running, an exhaust valve collapsed, the head of which dropped into No.3 cylinder, scrapping one piston. Complete new set of valves fitted EB.165 and a new piston to the same specification as above. Up to this time all running had been carried out on Pratts 'Ethyl' fuel, and lead deposit on the valve seats gave rise to the assumption that the valves had been overheated due to this deposit acting as an insulator, thus preventing sufficient heat being carried away to the cyl. head. After a further 7½ hrs. running on DTD.134 fuel, the unit was dismantled for inspection, and the pistons found to be in perfect condition. 11 Hrs. 15 mins at 4000 R.P.M. } 15 Hours. 3 Hrs. 45 mins. at 4350 R.P.M. } Oil consumption for the 15 hrs. run = 1.87 pts/hr. Hs{Lord Ernest Hives - Chair}/C.T.Salt. | ||