Pushrod problem

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Pinger

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1) Tighten the rocker until you can roll the pushrod between your thumb and forefinger with the slightest bit of resistance.

2) At this point tighten between an additional quarter to half of a turn.

Working on my 5.7 Vortec today I noticed a load of pushrods as per step 1). Does that mean I need to adjust them as per step 2)?
When adjusted as per step 2), is it possible to do the twirl thing or are they too tight for that?
 

smokymtn65

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Working on my 5.7 Vortec today I noticed a load of pushrods as per step 1). Does that mean I need to adjust them as per step 2)?
When adjusted as per step 2), is it possible to do the twirl thing or are they too tight for that?

To tight unless you are superman! You will feel the difference pretty quick from spinning with your finger tips.
 

Supercharged111

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Setting preload with poly locks is the bees knees. You take up all the preload by hand then add your desired preload. FWIW factory spec is 1 full turn.
 

Captainfab

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What do you mean by intalled correctly? I removed everything that was supposed to be taken out and also went ahead and replace the valve seals

Did you install the cam correctly in time with the dots on the timing gears lined up? It also sounds like you had the valve lash seriously out of spec. You can not honestly at this time say that you do not have any bent valves if ypu have not done a compression test, leak down test or pulled the heads.
 

Alexisobs95

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Did you install the cam correctly in time with the dots on the timing gears lined up? It also sounds like you had the valve lash seriously out of spec. You can not honestly at this time say that you do not have any bent valves if ypu have not done a compression test, leak down test or pulled the heads.
Yeah I intalled correctly dot to dot in timing truck started right up with no problem and like I said no valves were bend already did a compression test
 

Frank Enstein

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Here is the procedure to adjust the valves on a new 8 cylinder engine:


Turn the crank clockwise while watching the number one cylinder pushrods.


Watch the exhaust pushrod go up and down and then the intake pushrod go up and down.


Continue to rotate the crank after the intake pushrod goes all the way down until the timing marks


Line up on 0 degrees.


(This will be LESS than 1/2 turn of the crank after the intake pushrod is all the way down.)


Install rockers and tighten the nut while rattling the pushrods up and down until the rattle just stops.


At this point you are at ZERO LASH.


Tighten further to add your preload ( typically 1/2 turn after the rattle stops ).


Do this to both rockers for number 1 cylinder. Cylinder number 1 is DONE!


Now turn the crank 90 degrees ( 1/4 turn) and set the rockers for the next cylinder in the firing order.


After the second cylinder in the firing order turn the crank 90 degrees and set the third cylinder in the firing order.


Repeat this procedure for the remaining cylinders, one for each 90 degrees of crank rotation


ending with the last cylinder in the firing order.



After the last cylinder is adjusted you should not need to touch them again.
 

Alexisobs95

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Here is the procedure to adjust the valves on a new 8 cylinder engine:


Turn the crank clockwise while watching the number one cylinder pushrods.


Watch the exhaust pushrod go up and down and then the intake pushrod go up and down.


Continue to rotate the crank after the intake pushrod goes all the way down until the timing marks


Line up on 0 degrees.


(This will be LESS than 1/2 turn of the crank after the intake pushrod is all the way down.)


Install rockers and tighten the nut while rattling the pushrods up and down until the rattle just stops.


At this point you are at ZERO LASH.


Tighten further to add your preload ( typically 1/2 turn after the rattle stops ).


Do this to both rockers for number 1 cylinder. Cylinder number 1 is DONE!


Now turn the crank 90 degrees ( 1/4 turn) and set the rockers for the next cylinder in the firing order.


After the second cylinder in the firing order turn the crank 90 degrees and set the third cylinder in the firing order.


Repeat this procedure for the remaining cylinders, one for each 90 degrees of crank rotation


ending with the last cylinder in the firing order.



After the last cylinder is adjusted you should not need to touch them again.
Thanks also I called the shop that sold me the cam and they told me they forgot to sell me the right pushrods that they were gonna call tomorrow to sell me the right ones would that be the issue ?
 

PlayingWithTBI

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I called the shop that sold me the cam and they told me they forgot to sell me the right pushrods that they were gonna call tomorrow to sell me the right ones would that be the issue ?
Could be, along with improper valve lash adjustment. What kind of shop would sell you the wrong push rods (if that's truly the issue)?

Another reason I like to use a length checker.:biggrin:
 

TechNova

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Bended is not a word. If you bent the pushrods there is a cause and probably a result other than the pushrods. Look for the cause not the result. a Pushrod a little too short would not bend, a pushrod a little long could bend but it would be because something hit such as retainer into guide or seal, which would damage them. The stud also could pull up. I would also be concerned about lobe damage and/or lifter damage. It needs to come apart and inspect everything, experience says push rods don't bend on their own.
There is no way I would put in pushrods and turn it over, you have other damage.
The problem with valve lash is there are different methods and some people use a little from multiple methods. Using the Comp Cams method on their website and rotating the pushrod works the best, wiggling ain't going to do it, prone to errors.
 

Pinger

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Given that my pushrods are easily turned, how soon do I have to adjust them - what are the consequences of running with them as they are?

On the plus side, them slackening is in the opposite direction of what would happen with valve/seat recession - something some motors on LPG are susceptible to.
 
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