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).
Specification sheet comparing Packard Super Eight and Packard Twelve engine components like pistons, connecting rods, and crankshafts.
| Identifier | ExFiles\Box 127\1\ scan0217 | |
| Date | 9th May 1935 guessed | |
| -3- Packard Super Eight Model 1203-1204-1205 | Packard Twelve Model 1207-1208 PISTON, CONT'D: Width of compression rings | 1/8 | 1/8 Width of oil rings | 5/32 | 5/32 Depth of ring groove (oil) | .158 | .158 Location of rings | Above pin | Above pin Height - c.l.of pin to top | 2 1/4 | 2.693 Piston ring gap | .007 min. | .007 min. CONNECTING RODS: Weight | 2 lbs. 15 1/4 oz. | 2 lbs. 8 3/8 ozs. Bearing material | Copper-lead Alloy | Copper-lead Alloy Centre to centre length | 10 3/8 | 9 Type of crank pin brg. | Removable steel backed shell | Removable steel backed shell Length of crankpin brg. | 1 1/2 | 1.1/8 Diameter of crankpin brg. | 2.3/16 | 2 1/2 Caps attached | Two bolts and nuts | Two nuts CRANKSHAFT: Type | Counterbalanced | Counterbalanced Material | Steel forging | Steel forging Number main bearings | Nine | Four Main bearing diameter | 2 5/8" | 2 3/4" Thrust take-on | No.7 | No.1 | ||