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 engine teardown of Chassis 3.AZ.20, the Continental Trials Car, detailing worn and broken components.
| Identifier | ExFiles\Box 146\1\ scan0209 | |
| Date | 16th March 1938 | |
| To Rolls-Royce Ltd. Derby ........ Ey. Copy to ....... Rm.{William Robotham - Chief Engineer} ........ Hd.{Mr Hayward/Mr Huddy} 1245 R/MTHS{Reg Matthews} SWDL{Len H. Swindell} Levallois Sr/VA4/ET.16.3.38 Re: CHASSIS 3.AZ.20 - CONTINENTAL TRIALS CAR Total mileage: 32,645 ------------------------------------------ We have partly dismantled the engine of this car in order to fit a set of connecting rods incorporating big-end bearing shells in Hall's A.C.6 alloy, as per Works memos Am2/R.18.1.38 and HPS.{Horace Percy Smith - Experimental Factory Mgr}I/VS.{J. Vickers}20.10.37. We attach two sheets showing the ovality and wear of the cylinder bores of "A" and "B" side cylinders. Upon dismantling the engine, we found that all the com-pression rings (top rings) were broken, with the exception of N°6 on "A" side and N°5 on "B" side. We are rather at a loss to account for this, except for the fact that there is a rather pronounced lip at the top of the majority of the cylinder bores. For your information, we fitted a new set of connecting rods (E.84691) on 31.1.37, after the car had covered 15,203 miles. The pistons rings, however, are the original ones. We find that the compression ring (top ring) of each piston shows signs of having hammered in the groove of the piston, as we find there is a .007" clearance between the ring and the groove. We shall be glad to have your opinion as to the probable cause of the breaking of the piston rings and what you consider that we should do. We are preparing a report concerning the bearings and the camshaft and tappets. These latter parts are in a poor condi-tion and will have to be changed. Sr/VA. | ||