Saturday, February 12, 2011

Valve Tappet Clearance for Rocker Arm Type

Rocker Arm for Valve Tappet Clearance
  The valve clearances for 3/4k for adjustable lifters can be set either when the engine is cold or hot. Both clearance are below in Thousands of an inch and mm.
COLD:
Exhaust valve:
 0.30mm
Intake Valve:
 0.25mm

HOT:
Exhaust valve:
 0.30mm
Intake valve:
 0.20mm



These are for motors with STOCK cams. When upgrading to a bigger aftermarket camshaft consult you cam grinder for new valve clearnaces. Some cams shops even list them in their on-line catalogues.
5k's, having hydraulic lifters do not have an adjustable valve clearance. If converting to solids use the above 3/4k specs (stock cams) or consult your cam grinder (for aftermarket).
When setting the valve clearances always make sure the cylinder you are working on is on its compression stroke. This is easy to do: With the tappet cover off turn the motor over (spanner on crank pulley) until you see the appropiate inlet valve open, keep turning till it closes and then give it another 1/4 turn or so. DON'T go so far that you start to open up the exhaust valve, you basically want it half way between the inlet closing, and exhaust opening. At this point both rockers should be "loose". Adjust both tappet and move onto the next cylinder.
After replacing a head gasket, its not a bad idea to check and re-adjust the tappets if required after around 500km.
Tools to use :
14mm socket or spanner (to remove tappet cover nuts)
Feeler guages
12mm ring spanner
Medium sized flat head screw driver

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