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).
Engine manifold design and harmonic damper considerations for various engine types.
| Identifier | ExFiles\Box 173\4\ img128 | |
| Date | 9th December 1935 | |
| -3- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/KW.9.12.35. Also a really large capacity manifold at least 4" dia. reduces the surging of pressure in the pipe and causes less blow back into the cylinders on opening the inlet valve. Very likely on losing the 30º seat and venturi the inlet timing will have to be made later. As regards harmonic dampers, these can be smaller than Lanchester ones and more effective, but do not cope with the 6 cylinder master period. The inertia should be 20% that of the crankshaft assembly including rods and half the pistons, and it should be tuned to 55% of the natural frequency. The best type is the Buick arrangement driven by leaf springs which supply the necessary damping. On the 45º Cadillac V-12 a small damper is all that is required. Timing chains greatly increase the ease of removal of torsional periods. A V-8 with timing chain and stiff crankshaft does not usually require a damper. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||