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hotrodharley 05-29-2017 08:11 AM

Push rod length
 
Building a 496 bbc;deck has only been cleaned and flaten out;;head gasket is .080[needed to drop comp due to decide to street use eng and wanted to be able to use pump gas]have afr oval v2 alum heads;;comp hyd roller cam xm284hr-12[547 lift]howaeds hyd roller lifters #91161;;;and comp cams #1620-16 roller rockers;;;put stock push rod in and checked patteren on valve stem and riding on edge of valve stem[toward outside of head]put my adjustable push rod in and rechecked;;same location;;no matter how short or long i make the adjustable push rod i still showing rocker roller setting on edge of valve steam;;;what am i missing or doing wrong;;first time checking push rod lengths;[i'm using marker on stem so can see line where rocker is riding and rotating eng where valve opens and closes at least 2 times];since heads says will need .200 to .250 longer push rod i figure i should check it;;;lot of money in eng and don,t want to destroy it by having wrong push rods;;

curtisreed 05-29-2017 03:53 PM

If you can't get it to move no matter where you put the length of the pushrod checker, I would look toward the rocker having the wrong pivot to roller tip length.

You might watch this video about checking midlift geometry.

https://www.youtube.com/watch?v=o5is9BsH5OU

dustinarens 06-23-2020 01:49 PM

When you are trying to check pushrod length with a hyd roller lifter the plunger is getting depressed due to the valve spring is overcoming the spring inside of the lifter. You will need to use a solid lifter with the same seat height/ a checker spring on the head/ or dissemble the lifter and take out the spring and replace with washers to make that lifter solid.


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