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).
Technical memorandum discussing suspension types, engine bore wear, lubrication, and piston/liner issues in various competitor vehicles.
| Identifier | ExFiles\Box 178\2\ img023 | |
| Date | 13th April 1940 guessed | |
| -2- Serial No.78 from Olley. at least ½" deflection vertically under load and preferably more. At the front end, this necessarily implies the type of unit suspension used on the Opel Kapitan and Chevrolet and the trick will be to obtain vertical softness as required without getting softness in other directions, which will make for sloppy handling. Bore Wear. The Chevrolet is the best car at the Proving Ground for bore wear and has been so for years. It will do 50,000 miles before honing the bores. After honing, the car is good for at least another 50,000 miles and is actually better because the distortions of the new casting have been removed by use. The piston ring makers confirm this statement. The Hudson engines are bad for distortion because of lack of water space between cylinders. Hudson can only get by, by pinning the rings and are the despair of the replacement piston ring makers. Splash lubrication with oil troughs in the oil pan as used by Chevrolet, with the oil jets flowing directly at the dippers, is undoubtedly the primary cause for their good cylinder bore conditions and their better oil consumption. Experiments in the nitriding of cast cylinder bores have been made but are not seriously regarded in the U.S. because if 50,000 miles can be obtained, the cylinder bores are considered as good as the rest of the car. The tin-plating of pistons is very largely practiced and the tin lasts surprisingly well, there being traces of it on the piston skirt after 25,000 miles. Co-directional honing of the bores is being practiced on automobile work just in an experimental way at present. Co-directional honing of the piston rings, however, is well advanced. Ernie Wilson says the Ford cylinder liners cannot be regarded as satisfactory, even for ordinary use in the hands of the public. What happens is that carbon accumulates behind the turned over flange at the top of the liner, causing overheating of the upper end, which then collapses and tries to seize the pistons. This occurred at 8,000 miles on the 1940 Ford Mercury. P.T.O. | ||