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).
Recommendation to modify the piston locking screw design for the 40/50 chassis to prevent distortion.
| Identifier | ExFiles\Box 35\2\ scan 148 | |
| Date | 8th October 1919 | |
| R.H. 235 A (100 T S.F. 575, 16-4-19) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2354. To Ds. from EH. c. to H.{Arthur M. Hanbury - Head Complaints} c. to Ly. c. to Ep.{G. Eric Platford - Chief Quality Engineer} ORIGINAL EM/LGS.10.19. 8th. Oct. 1919. PISTONS FOR 40/50 CHASSIS. X.3400 On the present piston we are using two locking screws in the gudgeon pin. The idea of the extra locking screw is to balance the other one. The holes for the locking screws are reamed to size. The limits for drilling the gudgeon pin and drilling the holes in the pistons are such that the holes can be out .008". It has been found on some pistons that if the locking screws are forced in, the piston is distorted. We recommend that the hole in one side of the piston for the locking screw should be made a clearance hole, when that is done the screw will simply be there to balance the other one. We cannot see that any possible harm can come because all our pistons on cars on the road have only one locking screw. EH. | ||