What do you use to measure lifter preload?

[Drewster]

I tried to use the back end of 12" dial calipers to measure lifter preload. i got measurements around .100in. (difference between loaded and unloaded lifter plunger). i wanted to find the most accurate method as the calipers were not on centerline when measuring
I saw the GNTtype article about using a wire style gap tool but that didnt make sense trying to measure depth.
what is an accurate method? maybe dial indicator on top of the rocker arm and pushrod?

Andrew
motor almost done.

 

[JDEstill]

I used a wire type method that I think is the same as that on the GN T-Type site. It's just measuring the gap between the top of the plunger and the snap ring that holds the plunger in the lifter body. I found a paper clip whose wire diameter was approximately the dimension I was shooting for (measured it with my micrometer), bent it into a straight piece with a short L at the end, and then just lengthened my adjustable pushrods until I could get that L in between the plunger and the snap ring.

Later on when I switched to a roller cam and needed to order new pushrods I just got an adjustable pushrod checker. With that you just install the checker as if it were a normal pushrod, lengthen it until you take up all the slack (which is at the zero preload point), check the length of the checker, then acquire pushrods that are 0.035ish longer.

John

 

[Just a Six??]

I used a wire type method that I think is the same as that on the GN T-Type site. It's just measuring the gap between the top of the plunger and the snap ring that holds the plunger in the lifter body. I found a paper clip whose wire diameter was approximately the dimension I was shooting for (measured it with my micrometer), bent it into a straight piece with a short L at the end, and then just lengthened my adjustable pushrods until I could get that L in between the plunger and the snap ring.

Later on when I switched to a roller cam and needed to order new pushrods I just got an adjustable pushrod checker. With that you just install the checker as if it were a normal pushrod, lengthen it until you take up all the slack (which is at the zero preload point), check the length of the checker, then acquire pushrods that are 0.035ish longer.

John

X2

 

[Drewster]

thanks for the info

do you measure the push rod checker with calipers, micrometers? or are there graduations on the push rod length checker?

 

[Just a Six??]

There are but I didnt use them & measured. Every turn is X amout & there are lines on it but I felt better measuring. I used a ruler & then at the machine shop. I was off by about 4 thous.

 

[bison]

Go to zero lash/preload and then count the number of turns as you preload. Then base the depth off the thread type.

 

[Rodney87GN]

or are there graduations on the push rod length checker?

There are...one full turn equals .050". But it's still quicker to just measure it.

 

[Drewster]

thanks again

Thanks again....I just got the Comp Cam length checker and will give it a spin.

Andrew