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).
Issues with rocker shafts, clutch performance, and crankshaft dampers.
| Identifier | ExFiles\Box 178\3\ img167 | |
| Date | 29th December 1932 guessed | |
| (3) I also understand that the rocker shaft has more flex than desireable, this is probably a defect in itself, especially at the overhanging ends, but it may be brought about by the high lift, and the very stiff valve springs. Required __________ Clutch. Clutch jaggers probably not due at all to rubber coupling, but more likely entirely the state of the ferrodo surface, or the new two step scheme, i.e. the pressure not progressive enough. Rubber part could be made solid for trial. __________ Crankshaft-Damper. You will see from my telegram that I am very suspicious that our dampers are not effective, if set up with much friction they fail to slip, when they do slip, they exert very little damped friction. We sent from W/W a dry centrifugal one, but it was said not to work. But Chrysler uses a weighted rubber one in a V grove, which is said to be good. Cannot understand why ours is wrong, if Chrysler is right. I feel there is great advantage in both centrifugal loading and dry friction. [now explained that centrifugal loading increases too rapidly. I therefore repeat 1/2 centrifugal & 1/2 permanent] I have no confidence in going back to well lubricated ferrodo, unless it is free from gummy make up. [we could find what surface is best & if. dry is better than lubricated.] The material I have always favoured is "Vulcanized Fibre", and I suggested it should be used thin, so that the moisture does not make it take up all the clearance. The necessity of limiting the cont'd V | ||