bent push rods again

[79 underconstruction]

rebuilt my 351m AGAIN bent push rods. why cant i get this right? im begining to think the builder who done the heads screwed up. i completly rebuilt engine, started to run break in, (comp cam instructions said 30 mins at 2500rpms) 1 min in to it, motor started popping thru carb. i shut it down, pulled rocker cover, BAM, same thing that happend in the first build, bent push rod! gotta be a clearance issue right? if so why is there only one bent? last time 4 bent

 

[Rons beast]

check with the cam manufacturer as to the length of pushrod that should be used with your cam and valvetrain.

You mentioned the heads were rebuilt. Was the head to deck surface milled? If so it reduces the valve to piston clearance and lifter to rocker length. What rockers are you using? How are you adjusting them? Is the installed spring height stock? Stock springs or aftermarket? thicker springs could bind if not used with the proper valve train components.

All things concidered, is sounds like as the motor heats up and things expand there is a clearance issue.

Gotta check all to find out what.

 

[79 underconstruction]

the machinist who done heads used all stock components, he checked springs said they were fine, he did say he trued deck surface a little, when i asked him he said he wouldnt call it a shave, less than.010

this set up is pedastl mount, just tourque to spec. im def gonna check with comp to see if they can give me recomended push rod length. good advice.