Pistons: aluminium step-head type with two compression rings and one oil ring
Valve tappet clearances
Inlet and exhaust valves: 0.024 — 0.026 inch = (0.61 — 0.66 mm)
*note: exhaust valves are of the free rotating type .
Valve stem cap clearance should be from 0.002 to 0.0045 inch.
Permissible wear limit is. 0.008 inch.
Distributor
Type: bosch u-vjur 6bl62t
Contact breaker gap: 0.012 to 0.016 inches = (0.304 mm to 0.406 mm)
Vaccum advance
Deg-adv: 9–11
Begin: In/hg: 4 ¾ --6
End: in/hg: 15
Centrifugal advance
Deg-adv: 14–16
Begin: 350–450 rpm
5° / 590–660 rpm
10° / 800–960 rpm
15° / —- rpm
End: 1180–1350 rpm
Ignition timing
Standard fuel: 3° before top dead centre (btdc) when the dot on the flywheel is in line with the pointer on the clutch housing, #1 and #6 cylinder pistons are 6° btdc. One graduation on the distributor scale or 3 1/6 inch (4.76 mm) of the flywheel rim represents 2°.
premium fuel: 6° btdc
Firing order:
1–5–3–6–2–4
Ignition coil
6 cylinder lucas type no. La121
Spark plugs
Severe service: klg fs-70
Normal service: ac 43, ac 44, campion j10
Plug gap: 0.028 inches to 0.033 inches (0.711 mm to 0.838 mm
