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).
Visit to Vauxhall's to finalise the Phoenix engine design, detailing Buick's power improvements.
| Identifier | ExFiles\Box 127\4\ scan0080 | |
| Date | 28th September 1937 | |
| 1097 also 1044 By.{R.W. Bailey - Chief Engineer} from Rm.{William Robotham - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. Da.{Bernard Day - Chassis Design} Rm{William Robotham - Chief Engineer}/CES. c. Da{Bernard Day - Chassis Design}/Jnr.{Charles L. Jenner} Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews} Rml/R.28.9.37. VISIT TO VAUXHALL'S. Da.{Bernard Day - Chassis Design} Jnr.{Charles L. Jenner} and Rm.{William Robotham - Chief Engineer} visited Vauxhall's on Thursday, September 23rd, with the object of obtaining information to enable the design of the Phoenix engine unit to be finalised. In particular, Taub has just returned from the States with the information as to how Buicks had managed to get 10% increase in torque from the push rod engine. It will be remembered that whilst they told us what they had done when we were in America, they would not tell us how they had done it. (1) BUICK POWER IMPROVEMENT. Buick's have modified the shape of their piston so that they get a combustion chamber which approximates to some of the shapes used on side valve engines. We attach a sketch showing roughly what they have done. It will be remembered that generally speaking the side valve engine runs at least ¼ ratio higher than the push rod engine in U.S.A. practice, due to the greater tendency of the overhead valve engine to detonate. It is for this reason that the push rod engine is so slightly ahead of the side valve engine, in spite of the fact that it has somewhat better volumetric efficiency. Buick's claim that by this modification they have raised their useful compression from 5.7 to 6.7, thereby increasing their torque 10% without increasing roughness or tendency to detonate. In production they are only raising their compression ratio to 6.3 owing to a certain amount of trouble they have had with blow-by, and, also, possibly because they want more experience with a modest improvement in power output. The uneven top piston is directly applicable to the Phoenix and our existing engines, and we recommend that we go ahead immediately with this as a project. | ||