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).
Endurance test report on Hall's metal bearings and modified valve gear for a 3.500' Bore Bentley.
| Identifier | ExFiles\Box 114\2\ scan0220 | |
| Date | 22th November 1935 | |
| 3.500" Bore Bentley. Endurance Test on Hall's Metal Bearings and Modified Valve Gear. An endurance test has been run on B-14 unit built up to specification RHC{R. H. Coverley - Production Engineer}/CP.4/KP.29.10.35, except that the engine was run with a standard induction system. Features of the engine were Hall's metal bearings (.0018 clearance) and modified valve gear with the tappet adjustment on the rocker arms. The compression ratio was 6.4/1. The test conditions were 30 mins. at 4,000 r.p.m., 25 mins. at 4,250 r.p.m., and 5 mins. at 4,500 r.p.m. in every hour. Oil temperature 100°C, inlet, water inlet 70°C. Ethyl fuel was used and Motorine 'C' oil. After 46 hours No.4 big end bearing failed and the engine was shut down. The condition of the engine was found to be as follows :- MAIN BEARINGS. Table Data: No.1 - Top Half: Large piece of brg. metal broken away from shell. Cap: Intact but pitted. No.2 - Top Half: Intact but pitted. Cap: Piece of brg. metal broken away. No.3 - Top Half: Intact but pitted. Cap: ". No.4 - Top Half: About half of brg. metal broken away. Cap: ". No.5 - Top Half: Piece of brg. metal broken away. Cap: Intact but pitted. No.6 - Top Half: Intact but pitted. Cap: ". No.7 - Top Half: Good, slight pits. Cap: ". | ||