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).
Endurance test of 'pedestal' pistons for a Phantom engine, investigating failures and piston knock.
| Identifier | ExFiles\Box 48\1\ Scan175 | |
| Date | 4th April 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to CJ. BJ. c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} X4490 Hs{Lord Ernest Hives - Chair}/ACL1/LG1.4.26. EXPERIMENTS WITH "PEDESTAL" PISTONS FOR PHANTOM & RECENT INVESTIGATION OF "PISTON KNOCKS". X4490 X8040 We have just completed an endurance test on the pedestal type pistons on a Phantom engine. The test was run at an average speed of approx. 2800 r.p.m. with reduced throttle giving 57 B.HP. or about 50% full throttle. One piston failed after 25 hrs. and another after 29 hrs. Both these pistons had the skirt break completely away from the crown just below the bottom ring groove. After the first failure the remaining pistons were carefully examined for cracks at the ends of the horizontal slotted portion but no trace could be found. A sketch showing the position of the fracture is given, which was exactly the same in each case. Previous to this endurance test the experiments have been chiefly directed towards curing piston knocks which are still manifest on Phantom engines. It cannot be claimed that this piston has overcome the trouble and with regard to contd :- [Text on blueprint image] POSN. OF FRACTURE ON PEDESTAL PISTONS SCH.701 FRACTURE | ||