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Valve train Geometry.

  
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Valve train Geometry.

 
Pontiacman8 Pontiacman8
Moderator | Posts: 5770 | Joined: 02/08
Posted: 12/16/13
08:12 AM

1 The first step is to install a solid lifter and an       adjustable pushrod. Mark the tip of the valve with a marker.
Verifyvtgeometry1

2 Install your rocker arm and set it up with zero lash. Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.

Verifyvtgeometry2

3 Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.
Verifyvtgeometry3

4aPushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip
Verifyvtgeometry4a

4bPushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.
Verifyvtgeometry4b

4cPushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.
Verifyvtgeometry4c  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8