Lashing Valves and setting plunger depth.
05-13-2018, 10:53 AM
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Lashing Valves and setting plunger depth. So I read through countless threads yesterday about this subject and not one person has mentoned this happening, at least from the explanations I could surmise. I am hoping to find someone whom has encountered this phenomenon I am having and can offer a remedy.
I have 2 5.7l Gen 3 motors In my shop. One I am rebuilding and the other is getting a cam swap. The issue I am having is the EXACT same on both. The rebuild has Summit Rockers, the cam swap has Harland Sharp with the shaft bar linking the pair per cylinder. The rebuild obviously has new lifters, but the cam swap has original lifters.
Now how can I have this issue with both, yet unable to read anyone ever have this issue....So I'll describe it now. But just to let you know so the trolls can settle down first, I have been working on cars for years, NEVER had this issue, but its obvious I have little experience with non adjustable valvetrain.
I setup my dial indicator to measure to the plunger depth at 22ftlb torque, and the lifter plunger doesnt move at all. Instead the valve draws down. 1 to 7 rocker ratio means .040 lifter plunger depth will not equate to .040 valve lift. So I can't just go off how much the valve is is being lifted off the seat. This is happening on both motors, where one set of lifter is brand new and the other has 180k miles.
To further complicate the situation, I left the shop the other night to go home, with the dial indictor in position and valve off the seat. Cam back to the shop 12 hours later next day and the lifter must have settled down. The dial indicator read .050 plunger depth and the valve didnt move when I looened the bolt, the lifter plunger did. But when I tried again only the valve lifts off the seat and the lifter plunger stays solid.
So WTF.... I need to wait 12 hours on each lifter to get the proper reading of depth???? This is happning on both old and new. I know where the base circle is so don't even try to say otherwise. The Harland Sharp rockers say to lash valves while on the compression stroke. The Summit rockers I am following the age old EO-IC (exaust opening Intake closing) procedure.
I know where and how the base circle is, I know what zero lash is, I have adjusted valvetrain for 30+ years, BUT Never had issues like I am having with non adjustable valvetrain.
So my questions are:
Are guys just ignoring the 22ftlb rule and making adjustments 1/2 turn after zero lash?
IS it normal to have the lifter plunger so stiff?
Do I need to remove the valve spring and put in a solid piece, or valve height checker in there at the current installed height, then run through the motions of torquing to find true plunger depth? Or heaven tell me there is an easier way?
Is there a racer reading this that could tell me what he does to avoid this by using a different technique to find exact measurements of his valvetrain?
I have 2 5.7l Gen 3 motors In my shop. One I am rebuilding and the other is getting a cam swap. The issue I am having is the EXACT same on both. The rebuild has Summit Rockers, the cam swap has Harland Sharp with the shaft bar linking the pair per cylinder. The rebuild obviously has new lifters, but the cam swap has original lifters.
Now how can I have this issue with both, yet unable to read anyone ever have this issue....So I'll describe it now. But just to let you know so the trolls can settle down first, I have been working on cars for years, NEVER had this issue, but its obvious I have little experience with non adjustable valvetrain.
I setup my dial indicator to measure to the plunger depth at 22ftlb torque, and the lifter plunger doesnt move at all. Instead the valve draws down. 1 to 7 rocker ratio means .040 lifter plunger depth will not equate to .040 valve lift. So I can't just go off how much the valve is is being lifted off the seat. This is happening on both motors, where one set of lifter is brand new and the other has 180k miles.
To further complicate the situation, I left the shop the other night to go home, with the dial indictor in position and valve off the seat. Cam back to the shop 12 hours later next day and the lifter must have settled down. The dial indicator read .050 plunger depth and the valve didnt move when I looened the bolt, the lifter plunger did. But when I tried again only the valve lifts off the seat and the lifter plunger stays solid.
So WTF.... I need to wait 12 hours on each lifter to get the proper reading of depth???? This is happning on both old and new. I know where the base circle is so don't even try to say otherwise. The Harland Sharp rockers say to lash valves while on the compression stroke. The Summit rockers I am following the age old EO-IC (exaust opening Intake closing) procedure.
I know where and how the base circle is, I know what zero lash is, I have adjusted valvetrain for 30+ years, BUT Never had issues like I am having with non adjustable valvetrain.
So my questions are:
Are guys just ignoring the 22ftlb rule and making adjustments 1/2 turn after zero lash?
IS it normal to have the lifter plunger so stiff?
Do I need to remove the valve spring and put in a solid piece, or valve height checker in there at the current installed height, then run through the motions of torquing to find true plunger depth? Or heaven tell me there is an easier way?
Is there a racer reading this that could tell me what he does to avoid this by using a different technique to find exact measurements of his valvetrain?
