lifter preload
03-31-2008, 02:19 PM
#1
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lifter preload can someone please explain to me how to set lifter preload ive got a loud lifter noise and dont know if its to much preload of ive got a lifter going bad since there are brand new i wouldnt think that is the case. so can someone explain how i check the preload on the lifter and also how i check the valve lash . new to this so please explain fully
03-31-2008, 06:00 PM
#3
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Do a search, there's lots of good information posted. Basically, you rotate the engine to the lowest point of the cam lobe (several methods to do this), measure the pushrod length required to just get the slack out of the rocker (several methods to do this) then add your preload number to that length. So for example:
Using the pushrod length checker (PLC) from comp cams to measure preload for stock lifters,
Rotate the engine until #1 cylinder exhaust valve is fully open
Install the PLC and tighten the rocker on intake valve
Unscrew PLC to just take up the slack
Carefully loosen rocker, remove PLC and count the turns to close the PLC
Let's say turns = 9 & 3/4. 9.75x.050 for each turn = .4875
Add that to 6.8 (base length of the PLC) = 7.2875
Now let's say you want .080 preload
7.2875+.080=7.3675
So your Push rod length in this example would be 7.375s for a .087 preload or 7.350s for a .062 preload since stock lifters call .060 to .120 preload (If I remember correctly).
Check several valves this way to get a good average and ensure the accuracy of your measurements.
Using the pushrod length checker (PLC) from comp cams to measure preload for stock lifters,
Rotate the engine until #1 cylinder exhaust valve is fully open
Install the PLC and tighten the rocker on intake valve
Unscrew PLC to just take up the slack
Carefully loosen rocker, remove PLC and count the turns to close the PLC
Let's say turns = 9 & 3/4. 9.75x.050 for each turn = .4875
Add that to 6.8 (base length of the PLC) = 7.2875
Now let's say you want .080 preload
7.2875+.080=7.3675
So your Push rod length in this example would be 7.375s for a .087 preload or 7.350s for a .062 preload since stock lifters call .060 to .120 preload (If I remember correctly).
Check several valves this way to get a good average and ensure the accuracy of your measurements.
03-31-2008, 06:13 PM
#4
one quick method you can do is, lets say #1 cyl-crank the motor over untill the ex. starts to open-then lossen the intake untill you feel some play in the rocker-now tighten it untill the play is just out of the rocker, then you should be able to get 1 1/2 to 2 turns to tighten (preload)
now crank the engine over untill the intake just starts to close, do the same thing to the ex rocker
this is a quick way to see where your at
now crank the engine over untill the intake just starts to close, do the same thing to the ex rocker
this is a quick way to see where your at
