Katech How-To: Check lifter preload
#1
Katech How-To: Check lifter preload
I get asked this a lot so I thought it would be helpful to post:
1) The only way to properly check (and know where you are in the travel) is
to use a special checking lifter or completely compress a stock lifter.
a) Checking lifter consists of a lifter that has been disassembled
to install shims that lock the plunger at the top of travel in the lifter body.
If using this method you would add length to the checking pushrod to put the
final pushrods into the middle of travel of the plunger.
b) Using a stock lifter, you must make certain that you have pumped
all the oil out of the lifter. To do this leave it at valve full open (highest
spring load) for a while with an indicator on the pushrod side of the
rocker. Watch to see when the indicator stops moving (when the plunger is
fully compressed in the lifter body). Once you have compressed the lifter
rotate the engine to close the valve, extend your checking pushrod to full
length. Using this method you will subtract length from your checking
pushrod to put the final pushrods into the middle of travel of the plunger.
2) Typical plunger travel on Gen 3/4 lifters is 0.150 - 0.200 depending on
the manufacturer, year, etc. We recommend 0.075-0.100" from the bottom of
travel (using method 'b' described above) or 0.075 from the top of travel
(using method 'a' described above). That will generally put you close to
the middle of travel. While there are many different strategies for where
to put the plunger, for street use we strongly suggest that near the middle
of travel is the safest for durability.
3) The more precise method of checking is 'a' because you are not guessing
that you got all the oil out.
With this though, I do have to make the disclaimer that since we are not doing the assembly ourselves, we cannot be responsible for any misunderstandings. We recommend assembly by experienced professionals to avoid possible issues.
1) The only way to properly check (and know where you are in the travel) is
to use a special checking lifter or completely compress a stock lifter.
a) Checking lifter consists of a lifter that has been disassembled
to install shims that lock the plunger at the top of travel in the lifter body.
If using this method you would add length to the checking pushrod to put the
final pushrods into the middle of travel of the plunger.
b) Using a stock lifter, you must make certain that you have pumped
all the oil out of the lifter. To do this leave it at valve full open (highest
spring load) for a while with an indicator on the pushrod side of the
rocker. Watch to see when the indicator stops moving (when the plunger is
fully compressed in the lifter body). Once you have compressed the lifter
rotate the engine to close the valve, extend your checking pushrod to full
length. Using this method you will subtract length from your checking
pushrod to put the final pushrods into the middle of travel of the plunger.
2) Typical plunger travel on Gen 3/4 lifters is 0.150 - 0.200 depending on
the manufacturer, year, etc. We recommend 0.075-0.100" from the bottom of
travel (using method 'b' described above) or 0.075 from the top of travel
(using method 'a' described above). That will generally put you close to
the middle of travel. While there are many different strategies for where
to put the plunger, for street use we strongly suggest that near the middle
of travel is the safest for durability.
3) The more precise method of checking is 'a' because you are not guessing
that you got all the oil out.
With this though, I do have to make the disclaimer that since we are not doing the assembly ourselves, we cannot be responsible for any misunderstandings. We recommend assembly by experienced professionals to avoid possible issues.
#3
Whats wrong with using a twist type pushrod length checker with normal lifters installed? Torque the rocker in place and expand the checker pushrod till it takes up all teh play. The weight of teh checker pushrod isnt enough to start compressing the lifter plunger, and you can feel when the play has been taken up. Now you know what length 0 preload is.
Just curious as to why your method would be more accurate?
Just curious as to why your method would be more accurate?
#5
I think their method "a" takes out the potential for someone to get "zero lash" wrong. I know on my Morel's, with the oil out and them new depressing the plunger was very very easy and you had to really feel for it. I was doing the adjustable Cranes though. It took me almost four hours to adjust the valves after I installed them
#6
Originally Posted by GuitsBoy
Whats wrong with using a twist type pushrod length checker with normal lifters installed? Torque the rocker in place and expand the checker pushrod till it takes up all teh play. The weight of teh checker pushrod isnt enough to start compressing the lifter plunger, and you can feel when the play has been taken up. Now you know what length 0 preload is.
Just curious as to why your method would be more accurate?
Just curious as to why your method would be more accurate?
I agree, what is wrong with this method???
#7
Originally Posted by GuitsBoy
Just curious as to why your method would be more accurate?
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#8
Originally Posted by brad8266
Because you will know %100 that the lifter will stay at zero lash by shimming it. Using a regular lifter it may preload without much pressure depending on how much oil is in it.
#9
Originally Posted by GuitsBoy
Not against a checker spring... I bought brand new lifters (no oil) and I could have bruised my hand pushing the plungers down with a pushrod. The checker spring will compress MUCH more easily.
#10
Originally Posted by brad8266
Well i just emptied a lifter and after its empty it pushes in really easy, i could push it with my pinky finger.
#11
Originally Posted by GuitsBoy
but compared to the checker spring which compresses much easier... Ive done it this way many times without issues, and I really cant imagine anyone else having issues with it. But hey, if you feel like going through all the aggravation, by all means, go for it.
It isnt too though hard to tighten the rocker arm and then elongate the pushrod checker till it is snug without loading the lifter.