Adjusting hydraulic lifters

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==Can I replace a damaged lifter with a new lifter?==
 
==Can I replace a damaged lifter with a new lifter?==
[[File:Lifter expolded view.jpg|thumb|200px|left|Arrow points to check ball retainer]]
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;{{Note1}} See [http://www.crankshaftcoalition.com/wiki/Lifters#Repairing_or_replacing_lifters Repairing or replacing lifters]
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[[File:Lifter expolded view.jpg|thumb|200px|left|Arrow points to check ball retainer on the end of the plunger]]
 
[[File:Lifter clips 002.jpg|thumb|350px|Three styles of lifter cup retainers. The [http://www.truarc.com/pdfs/Truarc%20Catalog.pdf internal C-clip type] is stronger and should be used especially with solid lifters or when "zero lashing" lifters.]]  
 
[[File:Lifter clips 002.jpg|thumb|350px|Three styles of lifter cup retainers. The [http://www.truarc.com/pdfs/Truarc%20Catalog.pdf internal C-clip type] is stronger and should be used especially with solid lifters or when "zero lashing" lifters.]]  
Before replacing a stuck or noisy lifter (which should only be done as a LAST resort), disassemble the lifter that is in question. You will see a cup, spring and check ball retainer (left) snapped onto the bottom center of the "piston" of the lifter. Often all that has happened is the cup assembly isn't fully seated into the recess on the bottom of the piston, or a speck of dirt has lodged between the check ball and seat. <br style="clear:both"/>
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When a lifter is noisy, often all that has happened is the check ball retainer assembly isn't fully seated into the recess on the bottom of the plunger, or a speck of dirt has lodged between the check ball and seat. This can be fixed, but requires the intake to come off to get to the lifter. Usually you can clean up the sludge inside the lifter using carb cleaner and it will perform fine again, but first check the surface of the lifter that faces the cam, if it's flat or concave just trash it, it must be sligthly convex.
 
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Remove the cup using a pick and see that the (tiny) spring and ball are there and that the ball isn't scored and that the seat on the piston that the ball seals, doesn't have any ridge or imperfections that would prevent the ball from seating properly.
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Shown above, left, is a disassembled GM hydraulic roller lifter. Most current flat tappet lifters have the same internal construction as this roller lifter, although there are different styles. But as long as the styles are the same, the piston from one can usually be fitted into another body. The arrow shows the location of the cup, spring and check ball assembly mentioned above.
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A better choice if the lifter's piston is found to be unrepairable, would be to replace the piston from another identical lifter, and reuse the lifter body that has broken in to the lobe that it started life running on. The lifter foot and the cam lobe quickly wear in together to become a unit- using a new lifter risks wiping out the cam lobe. This is also why it is not recommended to replace a used set of lifters with a new set on a used camshaft.
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The lifter body ID and the piston OD are a very close tolerance fit- the closest tolerances in the entire engine. Because of this, there's a chance that one piston won't work the exact same as the original. As long as the piston doesn't fit too tightly, this won't be a problem in the vast majority of cases, but should be mentioned just the same. The clearance between the piston and body is what regulated the bleed down rate. But having a slightly different bleed down rate is much preferred over putting a new lifter onto a used cam lobe in this writers opinion.  
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Shown left, is a disassembled GM hydraulic roller lifter. Most current flat tappet lifters have the same internal construction as this roller lifter, although there are different styles. But as long as the styles are the same, the piston from one can usually be fitted into another body. The arrow shows the location of the cup, spring and check ball assembly mentioned above.<br style="clear:both"/> Details are at the page linked to above.
  
 
===Chevy OEM hydraulic roller cam and lifters===
 
===Chevy OEM hydraulic roller cam and lifters===

Latest revision as of 20:09, 1 December 2014

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