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).
Details on engine lubrication, ignition system, and a piston comparison table for various models.
| Identifier | ExFiles\Box 125\2\ scan0049 | |
| Date | 14th June 1929 guessed | |
| contd :- -4- There are holes .312" dia, and chamfered in the journals, feeding oil to the pins; at the pins the dia. of the oil hole is reduced to .150". There are no grooves in the big ends which are whitemetalled direct, but a small hole in each rod (a "metering aperture") is arranged to register once each revolution with the crankpin oil hole. This is supposed to spray oil on to the cyl. bores and valve gear. The crankcase is ventilated from front to rear. An oil filter on the dash consists of a cartridge containing treated fabric, through which the oil is circulated. The complete cartridge is supposed to be changed every 10,000 miles. The Instruction Book says that the initial clearance is .002" on all engine bearings, and that new main bearings may be installed without reaming or scraping. IGNITION SYSTEM. This is by coil and double distributor, one contact breaker firing cyls. 1 - 3 - 2, and the other cyls. 5, 6, 4. The firing order is 1.5.3.6.2.4. The cam is 3-lobed. There is a semi-automatic spark advance. PISTON. This is a proprietary article and is shewn on fig.4. It is rather heavy as shewn by the following table : ENGINE. | Wt. of piston + pin & rings. lbs. | Bore of cyl. ins. | Piston wt. lbs/sq.in. of bore. Std. 20 HP. | 1.070 | 3.000 | .1515 Chrysler. | 1.562 | 3.250 | .1883 Std. Phantom. | 2.476 | 4.250 | .1746 contd :- | ||