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).
Mechanical weakness of miniature sparking plugs smaller than 14mm.
| Identifier | ExFiles\Box 58\2\ Scan095 | |
| Date | 10th May 1934 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. Rg{Mr Rowledge}/Rbr.{Mr Rubbra} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}8/KW.10.5.34. Miniature Sparking Plugs. For car work our greatest objection to sparking plugs smaller than 14 m.m. is that they become mechanically weak. We had to get the manufacturers to improve the barrels of the 14 m.m. plugs to prevent twisting them off the top of the screw thread. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||