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).
Piston seizure in a Bentley Car B.E.V. engine, detailing previous decarbonisation and engine specifications.
| Identifier | ExFiles\Box 97\5\ scan0252 | |
| Date | 29th December 1940 | |
| Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} File 4006 Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager}4/ML.29.12.40. BENTLEY CAR B.E.V. We have just had No: 1. piston seize up in the engine of the above car, Unit B.V. No: 7. - after running a total mileage of 17,219 miles. This engine was decarbonised after 10,887 miles, by removing the cylinder head and scraping the tops of the pistons, and we attribute the seizure to particles of loose carbon having worked down the top land of the piston and sticking up the top ring. The engine was given a top decarbonisation because of excessive detonations. The combination of a 7:1 compression ratio and raised crown pistons, which are carbon conscious, coupled with Pool petrol necessitated the cylinder head and piston tops being kept reasonably clear of carbon. Cylinder Block EX.34206 Nickel Chrome Molybdenum B.V. Pistons. Raised Crown Plated. 7/1 compression ratio. Identification No: EA.17. Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} | ||