Pushrods not rotating

[TR6oldtimer]

What are some of the reasons this would happen on a newly rebuilt engine? FYI, the valve lash is properly set, and the pushrods, rockers, and lifters are all new.

 

[trfourtune]

Hi,
I can think of 2 possiblilities:
1. something is binding(probably not)
2. the cam and lifters are not ground properly.
the lifters need the correct radius on the end which needs to match the cam grind properly. The end of the lifters have a radius that is not easily visible. Talk to the cam supplier to check what this should be and verify the end of the lifter. My cam supplier requires between 80-100 inch radius on the lifter.Put a straight edge across the end of the lifter and check for light passing under the ends. We are NOT talking about any kind of edge chamfer-there should be almost none depending on the cam. Also try more revs in the engine when inspecting to make sure.
keep us posted
Rob

 

[Deleted member 8987]

Another cause can very well be the socket on the top end and the ball adjuster.
If too tight or burred, won't rotate.
Rotation is, as stated, caused by radius on end of lifter, and it is not positive.
It's a faint effect, kinda like waving the Vermouth lid over your Martini.
Find a rod that is loose, i.e. valve fully closed with "rattle" in the rocker, see how much tension it takes to rotate the rod.

Did you oil the socket end before assembly?

It should break in if just a tad too tight.