With sketches comparing T-slot and Trans-Slot piston designs, materials, and performance.
| Identifier | ExFiles\Box 170\2\ img213 | |
| Date | 9th November 1934 | |
| E.C to W.O. By Wd. {Mr Wood / Mr Whitehead} holes on Pistons. Just gathered from Byron Ellis. At present we are using pistons with T slots thus :- These are in Lynite possibly similar to Y alloy. The difference in practice between this and Low-Ex. is not marked. They are all "anodyzed", but the actual effect of anodyzing on wear is doubtful. Probably helps during the break-in period. "Trans-Slot" pistons thus :- with inside pillars thus :- Are proving more successful than the T slots & have as little hot friction | ||
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).