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).
The chalk testing of B3 and B6 Bentley pistons for cracks.
| Identifier | ExFiles\Box 86\2\ scan0161 | |
| Date | 22th November 1933 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from RHC.{R. H. Coverley - Production Engineer} X236. RHC.{R. H. Coverley - Production Engineer}1/BE22.11.33. BENTLEY PISTONS B3 and B6 Pistons have been chalk tested for cracks as requested, the attached print shewing the condition of B3 Pistons, out of the Black Touring Car. Each piston in this set is cracked either across the webs or through the gudgeon pin bosses. B6 Pistons are sound except for two small cracks in No.5, one extending downwards from the bottom ring stop, and the other from one of the scraper ring drain holes to the horizontal slot. Both cracks are approximately in line with the saw cut. EB1299 - LeC 3675 Nº5 PISTON B6 UNIT. RHC.{R. H. Coverley - Production Engineer} TEST. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1800 Miles in Open Car. | ||