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).
Report on cylinder rebores for the month of May, including case examples and general reasons for regrinding.
| Identifier | ExFiles\Box 103\2\ scan0089 | |
| Date | 10th June 1938 | |
| To By.. from GWH.{George W. Hancock - Head Chateauroux} Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}19/N.10.6.38. Cylinder Re-grinds. -------------- With reference to your memo BY.20/G.2.6.38, I am enclosing the report for month ending May for cylinder rebores. On sheet 1, giving the rebores, the following may be of interest: Resale B.172.JD.{J. Draper - Frames} 22069 miles, taper .011 ovality .008" Paid R.20. Private B.139.EJ, 59963 miles, charged in full. Resale B.24.AH. 66225 " " " " Private B.78.BN.{W.O. Bentley / Mr Barrington} 30741 " " " " Resale B.117.AE. 46000 " " " " Private B.68.HK.{Col. T. Harker - Sales} 29693 " charged half price owing to Owner objecting. The bores were .009" taper .0055 ovality. Resale B.115.AE. 57287 miles, charged in full. The general reason for regrinding is: (1) increased oil consumption. (2) piston slap can be dismissed as far as K.{Mr Kilner} is concerned. (3) over-oiling is rare, possibly one case per quarter and generally this is due to worn valve stem packing (4) smoking exhaust very rare, does not worry K.{Mr Kilner} Cylinder re-grinds are governed by the wear factor, principally the amount of ovality. Up to .008" taper .002" ovality in the case of an owner's complaint of heavy oil consumption, HP rings provide an almost certain solution. Above .008" taper and .003" ovality an R20/30,000 miles, it is doubtful whether new rings fitted will control the oil and give a reasonable consumption even with lapping. -- GWH.{George W. Hancock - Head Chateauroux} | ||