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).
18,000-mile engine wear report on vehicle 21-G-IV, detailing issues with bearings and valves.
| Identifier | ExFiles\Box 5a\4\ 04-page228 | |
| Date | 27th February 1935 | |
| x5840 To Eg. from HH/GWH.{George W. Hancock - Head Chateauroux} c. to Mer. c. to E.{Mr Elliott - Chief Engineer} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Al. c. to Mx.{John H Maddocks - Chief Proving Officer} Hm{Capt. W. Hallam - Head Repairs}/GWH.{George W. Hancock - Head Chateauroux}10/KS. 27.2.35. Report on 21-G-IV - 18,000 miles. ENGINE UNIT C-14. At 18,000 miles the engine oil was changed from Castrol 'H.{Arthur M. Hanbury - Head Complaints}' to Wakefield's 'CW' oil, to obtain a comparative test on the wear of the bearings. Upon dismantling the engine we found that with the use of the thinner oil a certain amount of disintegration of the connecting rod bearings had taken place, chiefly on the loaded side, i.e., top halves. Number five connecting rod top half had started to break up. A piece of the lead bronze metal had broken away from number three main. Cylinders & Head, 14F. K.58676. Valves & Fittings, 18F. K.55577. The exhaust valve clearance on No. 5 cylinder during the latter part of the mileage was not maintained and it had to be adjusted frequently. Upon examination the valve head was found to have cracked three quarters of the way round on the underside. It is assumed that the use of Ethyl in the petrol was the cause. The remaining exhaust valves were in a poor condition, the seatings having distorted. This had caused faulty starting up from cold. The inlet valves had not been affected and were in a good condition. No valve springs had broken. We found two of the retaining clips had come out of the groove of the valve stem. The remaining clips do not appear to have sufficient spring tension to hold them firmly in position. The cylinder head was in good condition. The cylinder bores had been well lubricated and showed no signs of score marks. | ||