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).
Technical report on the engine of an Alfa-Romeo car.
Identifier | ExFiles\Box 179\3\ img027 | |
Date | 3rd March 1932 | |
To R.{Sir Henry Royce} From Hw/Gry.{Shadwell Grylls} c. to Dr. c. to Or. c. to Rg.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to HY.{Tom Haldenby - Plant Engineer} Hw/Gry.{Shadwell Grylls}3/W.J.3.3.32. Kus. 82. Re. Alfa-Romeo Car. Technical Report. (1) ENGINE. The six cylinder engine has a capacity of 1750 cc., 65 mm. bore x 88 mm. stroke and is supercharged giving 76 HP. at 4400 RPM. It is three point mounted on two feet (part of the crankcase casting) at the rear and a single point at the front; this latter is on the supercharger casing, and exerts no torsional restraint. Power is transmitted through a multi-plate clutch to a four speed central change gearbox. The crankcase (both halves) are of Aluminium and the block and detachable cylinder head of cast iron. (a) Crankshaft Assembly. This is a five bearing crankshaft with disc webs, and integral balance weights balancing exactly the crankshaft only. The rear of the crankshaft ends in splines on which is mounted the flywheel flange secured by a locked nut. This flange in turn carries a sleeve consisting of Nos. 4 and 5 bearings separated by a skew gear that drives the dynamo and water pump. Behind this sleeve and just in front of the flywheel flange is a bronze bevel wheel that meshes with the vertical drive to the camshaft. The front end of the crankshaft ends in internal teeth that drive the supercharger. The following figures were found by measurement :- Stiffness of crankshaft 62,000 lbs.ft/Radian. Polar moment of inertia of crankshaft 145 lbs. in.2 Inertia of supercharger rotor 12.4 lbs. in.2 Inertia of big end of Con. rod. 17.2 " " Inertia of reciprocating mass 8.7 " " Inertia of flywheel 278 " " (Calculated master period 7200 R.P.M.) Wt. of con. rod 1.172 lbs. Length between centres 7.500 ins. Weight of piston .750 lbs. The steel con. rods (286 Brinell) are off set. The gudgeon pins are located sideways by a set screw in the little end that mates with a flat on the gudgeon pin. | ||