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).
Chassis 93-NK after 5,447 miles, detailing engine and steering column issues.
| Identifier | ExFiles\Box 180\M3\M3.5\ img032 | |
| Date | 16th April 1925 | |
| R.R. 493A (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -1- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/GMH/Cm16.4.25. REPORT ON CHASSIS 93-NK CAR AFTER 5,447 MILES. ENGINE. The engine had run particularly smooth up to the big-end going on No.2 conrod. All the white metal has run out of this end. We have no explanation to give but that some foreign matter had passed through the filter. This we know can happen, as very fine pieces of white metal had passed through to the filter of the oil relay, where it had been held up by the filter there. We had been doing some high speed running, but the car had slowed down on a corner when the bearing went. This was nine miles from the garage. The journal on the crankshaft does not appear to be damaged. There are the marks of the grooves of bearing caps, but these are white metal marks. The oil filter was fairly clean. We have taken cyl. head off - Nos. 1, 2 and 3 pistons shewed considerable over-oiling. Nos. 4, 5 and 6 pistons were all well oiled. There was a thick deposit of carbon on the pistons, also outer ridge of cylinder. Valves also have a heavy deposit of carbon. Exhaust valve heads have distorted slightly, bedding being approximately half way round seat. These have all been ground in and are now O.K. Inlet valves were very good. Guides of all valves are good - no undue wear appears to have taken place. Mag. and Dyn. drives O.K. Water pump housing and packing O.K. Exhaust boxes have retained their positions since last fitting up, when more clearance was given to dowel pins. Cast iron choke valve in down take pipe seizes slightly occasionally, but becomes free on its own. At no time has it remained open when car has returned to garage. Carburetter - butterfly throttle has given no truble. Car has been particularly good for absence of exhaust explosions on overrun. Filter - very small amount of dirt and fluff. Air valve diaphragm - the diaphragm has now a movement of .0312" up and down, due to the whole becoming elongated where pin goes through dash pot. Oil relay - leather washer has got hard, and top half broken away - new washer required. It still functions, but is sluggish. Filter in same had fair amount of fluff deposit, also small particles of white metal. Front engine suspension O.K. Steering column. Bottom corner of steering column flange, nearest engine, found broken. This has broken away close to tube. Other parts of steering are O.K. Side steering tube and cross steering tubes are quite O.K. contd :- | ||