bending push rods please help

[optimus]

just installed a used engine in my sisters truck and I'm having major push rod problems. the #4 cylinder valve closest to the front and #6 cylinder closest to the front will bend within a few minutes of starting the engine running at an idle. before they bend the engine runs great valves and springs are moving up and down as they should then it starts tapping and bending. I have already replaced the rocker arms with some i know to be good and am stumped.

somebody who has experience with this issue please respond

thanks in advance
James

[optimus]

I'm going to pull the injectors in the morning and swap them with some good used ones to rule out over fueling and hydro-lock might even go buy a camera to check inside the cylinder.

any ideas guys?

[optimus]

swapped the injectors and still bending push rods I can see the lifter and the retainer they appear fine. it has me stumped it will run just fine till it clatters once then its bent.

anyone have any thoughts?

[SWIFTSERVICE]

maybe a valve guide that worn severly causing it to bind,is it smoking any

[optimus]

We figured it out the lifters were pressuring up and binding causing to much lift and bending the push rods we put some BG M-O-A in the engine and ran it with the rockers slightly loose for 20 min re-torqued the rockers and all is good so far.