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).
Foreign matter in the oil passages and connecting rod issues on a Continental Trials Car, Chassis 3.AZ.20.
| Identifier | ExFiles\Box 146\1\ scan0247 | |
| Date | 9th May 1938 | |
| To ROLLS-ROYCE Ltd. Derby..........HPS.{Horace Percy Smith - Experimental Factory Mgr} Copy to Rm.{William Robotham - Chief Engineer} By RHC.{R. H. Coverley - Production Engineer} Levallois Re: CHASSIS 3.AZ.20 - CONTINENTAL TRIALS CAR. Referring to HPS.{Horace Percy Smith - Experimental Factory Mgr}2/VS.{J. Vickers}4.5.38, the contents of which we fully appreciate, the following are, however, our comments: I. FOREIGN MATTER IN THE OIL PASSAGES. With reference to paragraph 8 on page I of our Sr/VAI/ET.29.4.38, we think that our remarks: "this being the third set of rods fitted to this car", needs explaining more fully to you, otherwise our remarks might appear to be misleading. When this car had covered 15.203 miles, we dismantled the connecting rods for inspection of the big end bearings. Two were found to be in a bad condition, the remainder being fair. Sr. sent a report to Rm{William Robotham - Chief Engineer}/Grys. as per Sr9/ET.1.4.37 concerning the above. The original rods were sent to the Works for examination and we fitted a new set. When the car had covered a further 17.442 miles, or a total mileage of 32.645 miles, we dismantled the connecting rods etc., in order to fit those sent to us as per your HPSI/VS.{J. Vickers}30.10.37 The condition of the dismantled rods etc., was fully reported upon in a memo which we sent to Ey., viz Sr/VA9/ET.17.3.38. You will therefore observe from the above that no actual failure occurred to the bearings of the original connecting rods or to those fitted at 15.203 miles. When we fitted the connecting rods incorporating Hall's alloy bearings, we did not remove the engine from the frame for a complete strip, for reasons of economy and we should mention that, in view of the mileage run by the car, which we do not consider as being very high, we did not suspect the presence of large plugs of foreign matter in the crankpins. The plugs removed were of a gummy, half solidified substance, as found in certain engines which have covered a very large mileage. They did not, however, cover up the oil holes in the crankpins (we should have been surprised if this had been so). This we particularly observed on N°6 crankpin, after the removal of the crankshaft. The size of the plugs was more what would have been expected with a car that had run twice the mileage, or more. Prior to fitting the new rods, the interior of the engine was cleaned as far as it was possible to do so with the engine in position, which is not an easy job. | ||