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 seizure of connecting rod bearings in Chassis 3.AZ.20 during continental trials.
| Identifier | ExFiles\Box 146\1\ scan0242 | |
| Date | 29th April 1938 | |
| Files SWDL{Len H. Swindell} 1245 To Rolls-Royce Ltd. Derby.......... Rm.{William Robotham - Chief Engineer} Copy to By.{R.W. Bailey - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} HPS.{Horace Percy Smith - Experimental Factory Mgr} Levallois Sr/VAI/ET.29.4.38 Re: CHASSIS 3.AZ.20 - CONTINENTAL TRIALS CAR Mileage: 52.244 Kms. With reference to Sr.'s conversation with you concerning the seizure of the bearings of N°6 connecting rod, the following is our report. We fitted to this car (engine in position) the complete set of new connecting rods incorporating big end bearing shells in Hall's AC.6 alloy sent to us as per Works memo HPS.{Horace Percy Smith - Experimental Factory Mgr}I/VS.{J. Vickers}30.10.37. Prior to fitting the new rods, we did not measure up the crankpins or the big end bearings, because we assumed these to be correct for size. Every precaution was taken during the fitting of the rods. The mechanic who fitted them had previously fitted two sets. After the rods were fitted up they were found to be free for side play on the crankpins. We carried out an oil flow test to the bearings and oil flow was O.K. from all the bearings. Prior to the engine being started up, the casing of the oil pressure filter was filled up with oil and the engine well primed. The engine was then run slowly with the car stationary for about three quarters of an hour. The car was then taken on the road and N°6 big end seized after the car had covered 80 Kms., during which time the engine was progressively run in. Upon dismantling the rods we found that the bearing shells of N°6 rod had seized half way across the bearing, which also caused the white metal for the strap rod to run. The remainder of the bearings were O.K. In view of the above and owing to the presence of a rather large quantity of white metal in the engine, this being the 3rd set of rods fitted to this car, we decided to remove the engine from the frame and entirely dismantle it and thoroughly clean all parts, etc... | ||