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).
Specifications and analysis of engine components, including piston rings, connecting rods, and crankshafts.
| Identifier | ExFiles\Box 125\2\ scan0050 | |
| Date | 14th June 1929 guessed | |
| contd :- -5- Invar struts are used each side to enable a smaller cold clearance to be used. The arrangement of the rings in pairs is of interest; it appears to be a development from having two rings in each groove i.e., they may be trying to reduce the amount of slackness and oil pumping that would result from wear with two rings in one groove. The overlapping edges of the rings do not touch but have about .003" clearance. The gudgeon pins are held in the rods. They are 7/8" dia., and smaller in bore at the centre than at the ends. CONNECTING ROD. This is of no particular interest being an 'I' section forging, whitemetalled direct. It is 10 7/16" long, and weighs as follows : Small end .719 lbs. Large end 1.937 lbs. Total weight 2.656 lbs. Total reciprocating weight 2.281 lbs. The pin is 2.00" dia. by 1.375" wide, and the actual bearing area is 1.150" wide. CRANKSHAFT. This has had a preliminary report, copy of which you have, giving dimensions and bearing areas; we have now completed our tests for stiffness and inertia. The torsional stiffness is 45,000 lbs.ft/radian. We have no reliable figures for existing India IV. and SS.{S. Smith} shafts, as these are under investigation. contd :- | ||