Pushrod Length Question...
Pushrod Length Question... Ok i got a pushrod checker from jegs (7"-8.170") and when this is how i used it. I need to know if this is correct....
1. Took two rockers off that where off there lobes (int and ex).
2. Put the adjustable pushrod down the hole and tightened a rocker arm over it to 22 lb ft.
3. Adjusted to zero lash and then carefully took the rocker arm off and the checker out.
4. Counted number of turns (7 2/3 turns) then did this
7" + (.050" x 7 2/3) + .060" (lifter preload)
and came out with 7.44333333".....
Is this reasonable with all stock ls1 parts but with 5.3L heads that are unmilled and using autozone stock replacement gaskets?
If this is correct what length should i get? Also how do i know if i am doing this on a lifter that hasnt bled down because that would mess the numbers up wouldnt it....I cant push it down when i put the pushrod in and push. Is this normal or should i be able to feel some bounce in the lifter?
Sorry for all the questions...Let me know what all you valvetrain gurus have to say
Thanks!!!
1. Took two rockers off that where off there lobes (int and ex).
2. Put the adjustable pushrod down the hole and tightened a rocker arm over it to 22 lb ft.
3. Adjusted to zero lash and then carefully took the rocker arm off and the checker out.
4. Counted number of turns (7 2/3 turns) then did this
7" + (.050" x 7 2/3) + .060" (lifter preload)
and came out with 7.44333333".....
Is this reasonable with all stock ls1 parts but with 5.3L heads that are unmilled and using autozone stock replacement gaskets?
If this is correct what length should i get? Also how do i know if i am doing this on a lifter that hasnt bled down because that would mess the numbers up wouldnt it....I cant push it down when i put the pushrod in and push. Is this normal or should i be able to feel some bounce in the lifter?
Sorry for all the questions...Let me know what all you valvetrain gurus have to say
Thanks!!!
Last edited by COJO_24; Nov 19, 2008 at 08:29 PM. Reason: used the tool wrong...but still want some input
Yes....i measured the pushrod and then added preload and came out with 7.44"
What i want to know is if this is reasonable or am i doing something wrong....if this is correct would i be ok with using 7.400" pushrods?
What i want to know is if this is reasonable or am i doing something wrong....if this is correct would i be ok with using 7.400" pushrods?
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Yes that's reasonable and ordering the 7.400 pushrods would be perfect.
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Two recent conversations with engine builders have indicated more preload is producing better dyno numbers. I wouldn't run stock lifters with that low a preload, any pump up and you will be tagging the clip, which is a very wimpy piece.
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Joined: Jun 2003
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Who were they? I'm sticking with .020, I've talked with several builders as well one with several records to his name.
How do i know that i wasnt checking the length on a lifter that has already bled down? That would mean with the length that i had on the adjustable pushrod, it would be bottoming out the lifter right? And isnt that bad
Right now i just have the 7.400" stock pushrods in it and it seems to be alright
Let me know what yall think
Right now i just have the 7.400" stock pushrods in it and it seems to be alright
Let me know what yall think
Last edited by COJO_24; Nov 24, 2008 at 06:29 PM.
You would have to push down pretty hard to bleed a lifter. The valve spring will take several minutes to bleed it down and the force is 70% higher than seat values, likely a couple of hundred pounds. With brand new lifters the plunger will move more easily though.
