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).
Letter from Buick Motor Company answering technical questions about their engine design, including push rods, pistons, and crankcase ventilation.
| Identifier | ExFiles\Box 124\3\ scan0425 | |
| Date | 4th January 1937 | |
| BUICK MOTOR COMPANY FLINT, MICHIGAN VALVE-IN-HEAD Buick STRAIGHT EIGHT January 4, 1937 Mr. L. H.{Arthur M. Hanbury - Head Complaints} Grylls Rolls Royce Ltd. Derby, England Dear Sir: Your letter of November 10th written to Mr. Chayne has been referred to the writer as Mr. Chayne is at present out of the city. We are answering your request in the same order as listed in your letter and trust that the information included will be of value to you. Wish to assure you that we are ready at all times to help you with whatever information we may have. 1. We use tubular push rods because they are lighter and will not bend as readily as solid steel push rods. We believe this warrants the additional expense over solid steel. 2. We are submitting a set of lash curves with the alumium rocker arm brackets, malleable rocker arm brackets and malleable rocker arm brackets with cooler, also a description of valve lash variation which explains in detail the reasons that alumium brackets compensate for the elimination of the oil temperature regulator in the rocker arm shaft. 3. The heat conductivity of Buick pistons is quite high and in order to reduce the heat carried to the top piston ring, and to distribute the heat as evenly as possible to all the rings, a heat deflecting groove between the top ring and the top of the piston has been provided. Heat from the top of the piston must either go through this groove or around it, and the heat conductivity of both air and carbon is much less than the heat conductivity of the piston. While this groove is slightly more efficient when free from carbon, it is still of great value when partly or completely filled with carbon. 4. The crankcase ventilation system removes fuel vapors, water and acid fumes from the crankcase. As fresh gases are drawn into the combustion chambers when starting the engine, a small amount of vapor may work past the rings and pistons into the crankcase where, if not removed, it will dilute the oil. Water vapor is formed during combustion and while most of it passes out of the exhaust system, a slight percentage of this vapor finds its way into the lower crankcase where it condenses into water. Considerable water is also "BUICK'S THE BUY" [Handwritten notes at top of page]: 1049. Please return GRY{Shadwell Grylls} | ||