Adjusting the tappets on pushrod engines
The point in the valve-operating sequence to check a pair of valves is when another pair is ‘rocking’ – the brief moment when the rockers are moving in opposite directions to close the exhaust and open the inlet valve.piston oil seals professional design.
For example, on a four-cylinder engine when the rockers on No. 1 are rocking you can check both valves on No. 4.
Turn the engine in its normal direction of rotation by using a spanner or socket wrench on the crankshaft-pulley bolt until the two chosen rockers rock.
Most engines turn clockwise, but some Honda engines and the Triumph Acclaim engine turn anticlockwise. Consult your car handbook. valve.piston oil seals professional design。
If in doubt, turn the crankshaft back a short way; but if you have gone too far, turn it on almost two more turns in the normal direction and look again.
At the cylinder to be checked, insert the blade or blades of a feeler gauge, selected for the correct clearance, between the rocker and the valve system.
If the clearance is correct, the blade is a close sliding fit between the two parts. If not, it may refuse to enter the gap, or it may be a loose fit, in which case you can move the rocker up and down with the blade in place.piston oil seals professional design.
Adjust an incorrect clearance with the rocker adjuster screw. If the rockers pivot on a shaft, the screw is usually at the pushrod end.When using the ‘rule-of-nine’ method, No.1 valve is fully closed when No. 8 is fully open.
When using the ‘rule-of-nine’ method, No.1 valve is fully closed when No. 8 is fully open.
There may be a slot-headed screw with a locknut. Use a ring spanner to loosen the locknut and turn the screw clockwise to decrease the gap, and the opposite way to increase it.
When the clearance is correct, hold the screw with a screwdriver while you tighten the locknut, then re-check the clearance. valve.piston oil seals professional design。
There may be a self-locking adjusting screw with no locknut. It has a hexagonal head: adjust it with a spanner.
Alternatively, there may be no rocker shaft, each rocker being held by a nut on a fixed pivot post. Adjust the clearance by tightening the retaining nut to reduce the gap, or loosen it to increase the gap.
After re-checking both valve clearances, turn the crankshaft until the next pair of rockers in the sequence rocks, and repeat the check. Carry on until all the valve clearances have been checked.piston oil seals professional design.
The point in the valve-operating sequence to check a pair of valves is when another pair is ‘rocking’ – the brief moment when the rockers are moving in opposite directions to close the exhaust and open the inlet valve.piston oil seals professional design.
For example, on a four-cylinder engine when the rockers on No. 1 are rocking you can check both valves on No. 4.
Turn the engine in its normal direction of rotation by using a spanner or socket wrench on the crankshaft-pulley bolt until the two chosen rockers rock.
Most engines turn clockwise, but some Honda engines and the Triumph Acclaim engine turn anticlockwise. Consult your car handbook. valve.piston oil seals professional design。
If in doubt, turn the crankshaft back a short way; but if you have gone too far, turn it on almost two more turns in the normal direction and look again.
At the cylinder to be checked, insert the blade or blades of a feeler gauge, selected for the correct clearance, between the rocker and the valve system.
If the clearance is correct, the blade is a close sliding fit between the two parts. If not, it may refuse to enter the gap, or it may be a loose fit, in which case you can move the rocker up and down with the blade in place.piston oil seals professional design.
Adjust an incorrect clearance with the rocker adjuster screw. If the rockers pivot on a shaft, the screw is usually at the pushrod end.When using the ‘rule-of-nine’ method, No.1 valve is fully closed when No. 8 is fully open.
When using the ‘rule-of-nine’ method, No.1 valve is fully closed when No. 8 is fully open.
There may be a slot-headed screw with a locknut. Use a ring spanner to loosen the locknut and turn the screw clockwise to decrease the gap, and the opposite way to increase it.
When the clearance is correct, hold the screw with a screwdriver while you tighten the locknut, then re-check the clearance. valve.piston oil seals professional design。
There may be a self-locking adjusting screw with no locknut. It has a hexagonal head: adjust it with a spanner.
Alternatively, there may be no rocker shaft, each rocker being held by a nut on a fixed pivot post. Adjust the clearance by tightening the retaining nut to reduce the gap, or loosen it to increase the gap.
After re-checking both valve clearances, turn the crankshaft until the next pair of rockers in the sequence rocks, and repeat the check. Carry on until all the valve clearances have been checked.piston oil seals professional design.
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