Lifters

Jump to: navigation, search
m (Break in of flat tappets)
(Replacing lifters: clean up; add text)
Line 62: Line 62:
  
 
==Replacing lifters==
 
==Replacing lifters==
[[File:Lifter expolded view.jpg|thumb|200px|left|Arrow points to check ball retainer]]
+
[[File:Lifter clips 002.jpg|thumb|350px|Three styles of lifter 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.]]  
+
 
[[File:Rhodes v max lifter.jpg|thumb|350px|Retainer clip used on Rhodes V Max lifters]]
 
[[File:Rhodes v max lifter.jpg|thumb|350px|Retainer clip used on Rhodes V Max lifters]]
 
{{Caution}}Lifters and cam lobes become wedded as soon as the engine fires up and the cam is broken in. From that point forward, the same lifter '''has''' to be kept on the same lobe, preferably in the same engine. To replace a faulty lifter with a new lifter (or to replace a used cam with a new cam, reusing the same lifters) is to ask for a catastrophic failure requiring the engine to be torn down to remove the shrapnel left from the destruction of the cam lobe(s) and lifter(s).<br><br>
 
{{Caution}}Lifters and cam lobes become wedded as soon as the engine fires up and the cam is broken in. From that point forward, the same lifter '''has''' to be kept on the same lobe, preferably in the same engine. To replace a faulty lifter with a new lifter (or to replace a used cam with a new cam, reusing the same lifters) is to ask for a catastrophic failure requiring the engine to be torn down to remove the shrapnel left from the destruction of the cam lobe(s) and lifter(s).<br><br>
  
Before replacing a stuck or noisy lifter with a new lifter (which should be considered only in an emergency situation), 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"/>
+
Before replacing a stuck or noisy lifter with a new lifter (which should be considered only in an emergency situation), disassemble the lifter that is in question.  
 +
 
 +
===Disassembling a hydraulic lifter===
 +
{{Note1}}Before beginning work, have a clean well lit work area prepared.
 +
 
 +
Use clean lint free rags or paper towels. To clean, use carb spray, acetone, lacquer thinner, or WD-40.
 +
 
 +
To disassemble a lifter, depress the lifter cup using a wooden dowel or a pushrod. This allows the retainer clip to be easily removed from the groove in the lifter body. Use a pick and lift one side out of the groove and the clip will come out.<br>
 +
{{Warning}}Be careful to not shoot it across the shop.
 +
 
 +
Once the clip is out, the pushrod cup and metering disc can be removed, followed by the inner plunger assembly. The plunger can be stubborn, tapping the open end against a cloth-covered wood block will usually bring the plunger to the top of the body allowing it to be coaxed out the rest of the way. 
 +
[[File:Lifter expolded view.jpg|thumb|200px|left|Arrow points to check ball retainer]]
 +
On the bottom of the plunger you will see a cup and a stiff spring. Remove the spring and set it aside. Inside the cup (left) is a small spring and check ball. The cup is a press-fit onto the plunger, it snaps off and back on. With a lifter that has collapsed or is noisy, often all that has happened is the cup 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.
 +
 
 +
Remove the cup using a pick and see that the tiny spring isn't bent, kinked or missing, and that the check ball is there and is smooth and shiny, and that the seat on the plunger that the ball seals doesn't have any ridges, burrs, or imperfections that would prevent the ball from seating properly. <br style="clear:both"/>
 +
 
 +
===Lifter reassembly===
 +
The plunger gets the cup containing the tiny spring and check ball (no lint!) snapped back into place. Be sure it's seated squarely on the bottom of the plunger. It doesn't take a lot of force, just be sure it's on all the way and sits square on the plunger.
 +
 
 +
Lightly lube the plunger using motor oil, put the stiff spring over the check ball cup on the bottom of the plunger, then insert the plunger assembly into the lifter body (again, no lint). Work the plunger up and down a few times (it'll take a minute to bleed the air from it) to verify it works smoothly and doesn't hang up or have any grittiness.
 +
 
 +
Next replace the metering disc and then the pushrod cup. Using a wooden dowel or a pushrod, depress the pushrod cup and reinstall the retainer clip. Again- be careful to not launch the clip into orbit.
 +
 
 +
At this point the lifter can be depressed and should return smoothly to being fully extended.
  
Remove the cup using a pick and see that the tiny spring and check 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.  
+
{{Note1}}If trying to repair a bad lifter and the lifter's inner bore is OK but the plunger is found to be unrepairable, replace the plunger assembly from another identical lifter and reuse the lifter body, then replace the lifter back on the same lobe it came from.
  
A better choice if the lifter's bore is OK but the piston is found to be unrepairable, would be to replace the piston assembly from another identical lifter and reuse the lifter body, then replace the lifter back on the same lobe it came from.
+
The lifter is the most precisely machined part in the engine. The plunger OD is matched to the lifter body ID, the close tolerances are required to give the correct amount of bleed down. For that reason, swapping out the plunger from one lifter to another will not always work, so plan on having to go through more than one lifter to find a good match to the old plunger OD. The MAIN thing is that the plunger not be too tight. Slightly loose will still perform OK, although there's a chance there could be some slight tapping at idle. But if the lifter and cam cannot for whatever reason be replaced as a set, this is STILL preferable to putting a new lifter on a used cam.  
  
{{Note1}}The lifter is the most precisely machined part in the engine. The piston OD is matched to the lifter body ID, the close tolerances are required to give the correct amount of bleed down. For that reason, swapping out the piston from one lifter to another will not always work, so plan on having to go through more than one lifter to find a good match to the old piston OD. The MAIN thing is that the piston not be too tight. Slightly loose will still perform OK, although there's a chance there could be some slight tapping at idle. But if the lifter and cam cannot for whatever reason be replaced as a set, this is STILL preferable to putting a new lifter on a used cam. 
 
 
*[[Lifters#Roller lifter|'''Return to Roller lifter''']].
 
*[[Lifters#Roller lifter|'''Return to Roller lifter''']].
 
<br><br>
 
<br><br>

Revision as of 03:54, 30 January 2013

Personal tools
Namespaces
Variants
Actions
Navigation
Categories
Toolbox