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).
The Packard 12-cylinder car, detailing engine specifications and dimensions.
| Identifier | ExFiles\Box 127\1\ scan0032 | |
| Date | 28th March 1917 | |
| R.R. 235a (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. COPY To R.{Sir Henry Royce} from HY.{Tom Haldenby - Plant Engineer} c. to J.{Mr Johnson W.M.} c. to Wor.{Arthur Wormald - General Works Manager} c. to Na.{Mr Nadin} c. to By.{R.W. Bailey - Chief Engineer} X.435 28th. March 1917. Hy{Tom Haldenby - Plant Engineer}1/NJ28317. Report on Packard 12-cylinder Car. Engine. 12 cylinders, 3" bore, 5" stroke, 2 sets of monobloc cylinders of six, the two blocks being set to form a Vee of 60°. Each cylinder block weighs 145 lbs. with valves, but no valve caps. The Valves are ordinary side by side type operated from a single camshaft running along the centre of the crankcase. The inlet manifold is in the form of a round passage cast in the cylinder block and is 1 3/4" dia. Valves. The valves are interchangeable and the rough dimensions are as follows:- [Diagram of a valve with annotations: 45° angle, bore of port in cyl. 1 1/2", 5/16" dia, 1 5/8", 5/32", 6 13/16"] Valve springs of .165" round wire, free length 3-1/16", outside dia. 1 1/4", number of turns 9. working range 2.562" to 2.262", lift of inlet valve .3", lift of exhaust valve .3". Pistons. The pistons are of aluminium alloy and are die castings. Weight of piston complete with 3 rings and gudgeon pin 14 1/4 ozs., gudgeon pin weighs 2 ozs. The 3 piston rings are 3/16" wide and are at the top end of piston. The ring joint is a patent one which I believe is known in America as the "Burd" Contd. | ||