
Rolls-Royce Enthusiasts' Club
SILVER GHOST REGISTER
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Ignition Timing of the Rolls-Royce 40/50 Silver Ghost




Battery Ignition
Set the contact breaker gap to 0.20”.
Turn the flywheel until the Number 1 piston is on its firing stroke (inlet and exhaust valves closed) and the mark B.L.I. (Battery Late Ignition) on the flywheel is aligned with the timing pointer on the clutch case. This is approx 1 ½” measured on the flywheel or 10 degrees ‘after’ top dead centre (TDC).
Fully retard the ignition lever (late) on the quadrant, the contact breaker cam should be at the point of opening the contacts and opposite the Number 1 segment of the distributor. Use of a continuity test meter will precisely determine the moment of points opening.
Magneto Ignition
Set the contact breaker gap to 0.015”.
Turn the flywheel until the Number 1 piston is on its firing stroke (inlet and exhaust valves closed) and the mark M.L.I. (Magneto Late Ignition) on the flywheel is aligned with the timing pointer on the clutch case. This should be approx ½” measured on the flywheel or 3 degrees ‘before’ top dead centre (TDC).
Fully retard the ignition lever (late) on the quadrant, the contact points should be at the point of opening the contacts and opposite the Number 1 segment of the magneto. Use of a tweeter will precisely determine the moment of points opening.
Firing Order
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1 – 4 – 2 – 6 – 3 - 5
Flywheel Markings
TDC Top dead centre
BDC Bottom dead centre
IO Inlet (valve) opens
IC Inlet (valve) closes
EO Exhaust (valve) opens
EC Exhaust (valve) closes
BLI Battery late ignition
MLI Magneto late ignition
BAI Battery advanced ignition
MAI Magneto advanced ignition