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 failure of Bensport gudgeon pin fixings after 5000 miles and the subsequent modifications tested.
| Identifier | ExFiles\Box 86\2\ scan0008 | |
| Date | 9th March 1933 | |
| Files X236 9.3.33. FAILURE OF BENSPORT GUDGEON PIN FIXING. After about 5000 miles running in France which included both track work and consistent high speeds on continental roads, it was found that the circlets retaining the gudgeon pins had become loose in the pistons, and had worn a considerable portion of the aluminium in their direct vicinity. The attached photograph shews the type of failure. It was noticed that the pistons in Cyls.4, 5 & 6, were considerably worse than pistons 1, 2 & 3. The first step taken was to fit aluminium buttons to retain the gudgeon pins as shewn on the prints attached to memo Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}9/KT.9.3.33. A new cylinder block and pistons were sent out to the car made to these drawings. During the preliminary test the car attained the speed of 96 m.p.h. on two occasions, which is equivalent to an engine speed of 4300 r.p.m. The crankshaft was fitted with the Chrysler type of balance weights, and observation on the test bed shews that at 4300 r.p.m. the fringe of the master period is reached. A further modification to the circlet rings is proposed in E.1/HP.8.3.33. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||