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).
Investigation into the cause and remedy for a camshaft squeak.
| Identifier | ExFiles\Box 13\2\ 02-page057 | |
| Date | 4th November 1929 | |
| X.7090 To Ev.{Ivan Evernden - coachwork} from Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} c.c. Mor. c.c. E.{Mr Elliott - Chief Engineer} c.c. Sft.{Mr Swift} Mx.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}3/AD4.11.29. RE - CAMSHAFT SQUEAK. We have been investigating a squeak that has developed in the camshaft on production cars. We have found after numerous tests that the squeak is caused by the rubbing of the tappet face on the cam face producing a vibration which becomes audible with the resonance of the crankcase. To overcome the squeak it is necessary to produce the tappet guides with the minimum clearance in conjunction with a perfectly smooth surface, also the base of the tappet must be very smooth and polished. The grinding of this face should be in the direction of the rotation of the cam and not as produced at the moment, which is crosswise. We have definitely proved that the squeak is not confined to any one tappet which at first was thought to exist is No.11 & 12 only and that the rear bearing was responsible. The rear bearing is a weak point, in so much that there is too much overhang of the camshaft. The minimum clearance of the camshaft bearings .0015" should be used as far as possible to damp out the vibration set up in the camshaft. We are further experimenting with bronze guides and with larger bearing surface of the tappet. Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} | ||