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).
Page 3 of a report detailing engine specifications for camshafts, ignition, and lubrication systems.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan35 | |
| Date | 28th January 1926 guessed | |
| contd :- -3- Inlet open 9º B.T.D.C. Inlet closed 49º A.B.D.C. Exhaust " 51º B.B.D.C. Exhaust " 8º A.T.D.C. The camshaft bearings are split diametrally like the big ends but in this case the rollers are arranged in a staggered order in the cages. There are seven bearings per camshaft. From the rear ends of the camshafts, drives are taken - one, a flexible drive to a Jaeger Tachometer and from the other a small cardan shaft to the two magnetos. The power absorbed in driving the complete valve gear was 4.3 H.P. at 5000 r.p.m. IGNITION. Two Bosch jump-spark magnetos driven as described above were timed to give a spark at 50º B.T.D.C. fully advanced. One magneto was used as a stand-by with a changeover switch to bring it on and cut the other out, if necessary. Much trouble with plugs was experienced at first but K.L.G. 180s and later K.L.G. 221s were found to give good results. LUBRICATION. Dry sump lubrication is adopted, a gear type pressure pump drawing the oil from the tank (arranged underneath the centre of the car and finned to assist cooling), and distributing it to the bearings and camshaft casings. The supply to each bearing is controlled by the size of the orifice or jet in the bearing housing or crankshaft. The cams are lubricated through a hole drilled on the periphery of the base circle. A scavenger pump returns the oil by way of a Mark honeycomb oil radiator to the tank. Castor oil is used. contd :- | ||