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).
Observations on engine noise insulation, induction, percolation, and hot-spots.
| Identifier | ExFiles\Box 178\2\ img114 | |
| Date | 2nd January 1935 | |
| -6- (2) Noise Insulation. This has been gone into earlier in this memo., and we think much more lavish use of noise insulating material should be made on the dashboard and floorboards. (3) 6-Cylinder Induction Pipes. A very small or even negative overlap is considered the best method of obtaining good slow running. Graham-Paige, who have done considerable work on 6-cylinder induction pipes, are emphatic that our arrangement of valves in which the end valves are inlets is wrong, and that inlets 2 & 3 and 5 & 6 should be together. It is easy to try this arrangement. Further, no American engine ticks over below 400 r.p.m. With the present efficiency in noise insulation such a fast tick over is not in any way objectionable. (4) Percolation. We think it worth while to experiment with a float chamber surrounding the choke. Strombergs say this cures the trouble of the engine not starting when hot, and Buicks maintain this is also beneficial in preventing a double transmission chunk on suddenly opening the throttle at low speeds. (5) Hot-Spots. Owing to the extremely cold conditions in Winter in the States, and the price of glycerine, alcohol is used as an anti-freeze. To prevent this rapidly boiling away, water temperatures run below 65°C. For this reason exhaust hot-spotting is necessary, also water heating is not adequate for immediate full throttle driving after starting the engine in cold weather. But for these two conditions the Americans would prefer water heating. | ||