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).
Instructions for timing the F.XI and XII engines.
| Identifier | ExFiles\Box 33\4\ Scan111 | |
| Date | 1st May 1928 guessed | |
| TIMING OF RR.F.XI & X11 ENGINES. For Instruction Book. (1) Set the inlet tappets on A1. and B6. cyls. with a clearance of .025". (2) With the camshaft drives disengaged, turn the engine until A1. piston is exactly on top dead centre, using the indicator provided. (3) Turn A.{Mr Adams} side camshaft so that A1. inlet valves are just about to open with a .010" feeler between the rocker and the valve stem, and engage the camshaft drive (A.{Mr Adams} side only.) (4) Before moving the engine, insert the indicator in B6. cyl. and then turn the engine forward until B6. piston is at T.D.C. (5) Set B. side camshaft so that B6. inlet valves are just about to open with a .010" feeler between the rocker and the valve stem, and engage the camshaft drive. (The camshafts are now correctly timed). The telescopic cover tubes must be released to hold the drive in position. (6) Replace the indicator in A1. cyl., and turn engine forward until the piston is at the next T.D.C. setting the indicator scale to the mark provided. (7) Rotate the engine back (to ensure freedom from error due to backlash in the gear, the engine should be turned back slightly beyond the mark and then brought forward to the M.A. position) a fraction of a turn corresponding to the movement shown from T.D.C. to M.A. on the indicator - or, more accurately, to a distance on the thrust housing (E.30357) circumference = 1.18" for an F.XI engine and 1.1" for an F.Xll engine. (8) With the distributors removed, and the distributor brushes opposite the no.6 segment, time the magnetos so that the contact points are just breaking in the position corresponding to full throttle when the controls are interconnected. (9) Reset tappets on A1. and B6. to .020" clearance. This should give an engine timing to correspond with the timing diagrams, and if a degree plate (timing disc) is available, a check should be made on the inlet Closing and M.A. positions with the clearances stated. contd :- | ||