I'm in the middle of a buildup (302w with trickflow heads) and just want some second opinions about the valve stem wear pattern I am seeing after adjusting my lifters. It doesnt look too terrible (in my limited experience), but its not quite on the center of the valve after rotating the crank through 4 rotations as you can see from the photo. What do you guys think?
Is my valve stem wear pattern OK
- Thread starter C0V3R
- Start date
thehueypilot
Active Member
No, they are too wide and should be more centered or just slightly inboard. The width should be about 1/16" wide max. Buy an adjustable pushrod to determine the exact length you will need otherwise you will wear out your valve guides real quick.
The pattern maybe OK, but it needs to be centered on the tip of the stem. You really need to use a set of "checking pushrods" to find out the length you need. Just off hand ( I may be wrong on this, visualizing it in my head) If the wear pattern is closer to the intake side, I think you need shorter pushrods, toward the exhaust side, longer ones.
thehueypilot
Active Member
The trick is to clean the end of the valve stem with carb cleaner. (use on rag) And clean the roller the same way to get all the oil residue off. Color the end of the valve stem with a black magic marker. Place the roller lifter onto the rocker arm stud and push down on the rocker arm firmly and twist back and forth about four to five times. Pull it back off and you should have a perfect witness mark to judge where the roller is touching the valve stem.
Top of the picture is center of the engine.
I am probably not testing it the best way - I tightened the lifters (normal, not solid or modified) to a little beyond zero lash with the pushrods I have available. I am thinking that when the lifters pump up the pattern may move inward more as the lifters are probably compressing during valve lift. Does this make sense?
I am probably not testing it the best way - I tightened the lifters (normal, not solid or modified) to a little beyond zero lash with the pushrods I have available. I am thinking that when the lifters pump up the pattern may move inward more as the lifters are probably compressing during valve lift. Does this make sense?
