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).
Report page analysing Bentley cylinder bore wear across different chassis series and piston types, with an accompanying graph.
| Identifier | ExFiles\Box 132\4\ scan0108 | |
| Date | 19th October 1937 | |
| -16- SW/Lths.3/H.19.10.37. In order to find if any particular series was bad for wear we have separated the figures according to series and the results are shown on Fig. IV. The increase in wear since the adoption of Aerolite pistons is very noticeable as shown by the increase in wear from series DG to series EF, when the Aerolite piston was first introduced on production. Another interesting feature of Fig. XIV is that since adopting the extra cylinder lubricating hole in the connecting rod, bore wear has not decreased. There are two possible reasons for increased wear since the adoption of Aerolite pistons. (1) Increased ring pressure from 9 lb/sq.in. to approx. 12 lb/sq.in. (2) Increased piston clearance. Figs. XV. and XVI show a comparison of centrifugally cast rings as represented by the Light Production Co. and Wellworthy's and single cast rings as represented by Hepworth and Grandage and Sealed Power Co. Contrary to expectations the hardness of the centrifugally cast ring is by no means as uniform as the single cast ring neither is the Brinell number as high. Graph Text: FIG. IV BENTLEY CYLINDER BORE WEAR Y-Axis: CYLINDER WEAR PER 1000 MILES (INCHES/10,000) X-Axis: SERIES OF CHASSIS. X-Axis Categories: AE AH BL BH CR{Mr Cra???ster / Mr Chichester} CH DG DK EF EJ FB FC GA GP Annotations: EB 1299 WITHOUT EXTRA CYL. LUBRICATION EB 1299 WITH EXTRA CYL. LUBRICATION AEROLITE. SMALL BORE. AEROLITE. LARGE BORE. Handwritten Note: MTHS{Reg Matthews} 11/37 | ||