Push rod measuring ...... Lets hear your procedure !

[awsomeears]

To be clear this is for a Flat tappet Hydraulic setup w/1.6 roller rockers

Alright guys I will be getting my heads back from Clocks off ( Thanks again Ron ) and I will bolt them up and start measuring the push rods, here are a few good articles that make sense but what I'm not clear on is the Preload of the hydraulic lifter. Reading more and more there are conflicting procedures....

I have the Comp cam tool to be delivered this week for measuring...

http://www.compcams.com/Products/CC-%27Pushrods%27-0.aspx
http://www.carcraft.com/techarticles/116_0401_setting_pushrod_length/index.html


I'd like a clarification on preloading the rockers just as you should when measuring for rod length ?

Yes pre load or just zero lash to get the mark on the valve stem ?

[awsomeears]

So am I just the only one attempting this ?

Ohh Shit :-)

Reading more and more I'm told that using a solid lifter is how you get the correct length, to me it doesn't make sense as a solid lifter has no preload like the hydraulic lifter, you would think the measurment would be off as most preload on a non reving pat 6000 sbc needs 1/2 turn preload.

[badass88gt]

When you are measuring for length you want zero lash. You will adjust your amount of lash with the rocker adjustment during final valvetrain setup. Install your solid lifter into a bore and set your adj pushrod to around stock length.

Make sure your solid lifter is riding on the base of the cam lobe (zero lift).

Color the valve tip with some black ink.

Put your rocker in place and adjust it so that there is zero movement of the pushrod between the solid lifter and the rockers cup.

Rotate engine clockwise until you've achieved one full lift cycle on that valve. I usually do two engine rotations.

Loosen rocker and inspect the mark that the roller tip of the rocker has left on the ink covered valve tip.

You want the pattern on the valve tip to be centered on the valve tip. If the pattern is up high, towards the lifter valley then you need a longer pushrod, if it's low towards the header then you need a shorter pushrod. Keep adjusting your pushrod until you get the mark/pattern dead center and as narrow as possible. Measure your adj pushrod and order that size or as close to it as possible. (Trickflow's are a great deal). You also want the sweep mark to be as narrow as possible. If it is a little off center but that is where it gives the shortest sweep, use that.

Also be sure to check that you have at least .060" clearance between the bottom of the rocker's body and the spring retainer too. Some Rockers do not provide enough clearance. Remember, if you have guideplates you will need hardened pushrods, which are a good idea regardless.

[2006wrxtr]

Yep just as above post says.
I made my own adjustable push rod by cutting a
section out of a spare push rod threading it and
using some allthread in the middle. Cheap and worked
well...

[awsomeears]

When you are measuring for length you want zero lash. You will adjust your amount of lash with the rocker adjustment during final valvetrain setup. Install your solid lifter into a bore and set your adj pushrod to around stock length.

Make sure your solid lifter is riding on the base of the cam lobe (zero lift).

Color the valve tip with some black ink.

Put your rocker in place and adjust it so that there is zero movement of the pushrod between the solid lifter and the rockers cup.

Rotate engine clockwise until you've achieved one full lift cycle on that valve. I usually do two engine rotations.

Loosen rocker and inspect the mark that the roller tip of the rocker has left on the ink covered valve tip.

You want the pattern on the valve tip to be centered on the valve tip. If the pattern is up high, towards the lifter valley then you need a longer pushrod, if it's low towards the header then you need a shorter pushrod. Keep adjusting your pushrod until you get the mark/pattern dead center and as narrow as possible. Measure your adj pushrod and order that size or as close to it as possible. (Trickflow's are a great deal). You also want the sweep mark to be as narrow as possible. If it is a little off center but that is where it gives the shortest sweep, use that.

Also be sure to check that you have at least .060" clearance between the bottom of the rocker's body and the spring retainer too. Some Rockers do not provide enough clearance. Remember, if you have guideplates you will need hardened pushrods, which are a good idea regardless.


One thing I want to double check with you is that I'm running flat tappet hydraulic lifters..... If you know that then Ok I get your procedure !!!

I will then have to borrow a solid lifter from someone :D

Stock sbc length is 7.800 and thats where I will start, yes I have guild plates and am aware of getting hardened push rods

Thanks much !

[badass88gt]

Flat rapper VS. roller shouldn't matter, procedure stays the same.

[badass88gt]

LOL autocorrected to rapper....

[badass88gt]

You could also go to the hardware store and get some very light checker springs and pull a couple of valvesprings. The idea would be to NOT let the hydraulic lifter collapse, which is why you use either soft springs or a solid lifter.

[awsomeears]

You could also go to the hardware store and get some very light checker springs and pull a couple of valvesprings. The idea would be to NOT let the hydraulic lifter collapse, which is why you use either soft springs or a solid lifter.

I totally understand what your saying, cool very cool !!!

One thing I will have to make sure on is the length of my hyd lifter vs the one I hope to borrow from either BCM or a few of my buddys

;)