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).
Technical report on piston flexibility tests, including a blueprint diagram, a table of results, and analysis.
| Identifier | ExFiles\Box 66\1\ scan0114 | |
| Date | 14th October 1926 guessed | |
| contd :- -2- BLUEPRINT DIAGRAM LABELS: CLOCK GAUGES 'V' PIECE PISTON 30 lbs WT. 2.50 TABLE: PISTON. | LOAD, LBS. | DEFLN: OF POINT 'A'. | FLEXIBILITY REL: TO STD: PISTONS. Present standard. | 30 | .007" | 1 Pedestal pistons. | 30 | .0105" | 1.5 Pedestal pistons with slot extended 180°. | 30 | .0155" | 2.21 We tested some pedestal pistons having the slot extended for 180° in an engine but found they gave rise to knocks or 'slap' even when cold - an indication that the flexibility was too great when used with the std. piston clearances. It therefore seems that the limiting value of flexibility which can be usefully employed on these pistons lies between these latter two values. We hope shortly to test some of the single bolt type pedestal pistons. Hs{Lord Ernest Hives - Chair}/A.{Mr Adams} C. Lovesey. | ||