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).
Front end drive systems, comparing timing gears to silent chains, and issues with coachwork rattles.
| Identifier | ExFiles\Box 178\2\ img210 | |
| Date | 23th February 1934 | |
| -3- He/Rm.{William Robotham - Chief Engineer} 5/KW. 23.2.34. FRONT END DRIVE. The following points emerge - (1) Silent chain drives are almost universal over here. (2) Cadillacs run 100 hour endurance tests at 4250 R.P.M. These chains are not their limiting factor they say. Numerous eights run over 4000 R.P.M. (3) When I put Mobile A.{Mr Adams} in the Bentley the gear sing can be plainly heard. Mobile A.{Mr Adams} is S.A.E.30. Mobil Artic is S.A.E.20. Manufacturers recommend, and most people here use, an ultra thin oil Standard S.A.E.10 for cold starting, and yet I do not remember hearing a front end howl or sing. (4) Nobody seems to have appreciable production difficulties with silent chain. Considering the costliness of our timing gears, the balanced cam, etc, that we have to fit to make good their deficiencies, ought we not to run an American engine to destruction to prove to our own satisfaction that we are right in sticking to timing gears. Is not the virtue of the chain its spool gear characteristics and its freedom from ring ? COACHWORK. I am repeatedly having rattles taken out of the Bentley body. I think we ought to put a medium priced American car through a 10,000 miles test to see if the all-steel body is really as free from rattles as we imagine, because whenever we treat a Rolls-Royce car as the chassis is built to be treated, rattles become a nightmare. I have been told that before Lincoln puts a Custom built body in production they produce as many as 30 or 40 experimental models and submit them to searching tests. I will try and get more first-hand information on the subject. He/Rm.{William Robotham - Chief Engineer} | ||