[Gene_J]

An occasional push rod will bend just because....

But a large number of them could be because the valves kissed the pistons or the valve springs were binding because of too much lift for the installed height of the springs.

 

[bishir]

Sometimes an overeagar lad overtightens the rocker arms.

 

[70calypsomach]

Well I can think of 4 causes of bent pushrods.
1. REALLY bad valve geometry.. Not very likely if you have the right parts (rockers, pushrods, valves, spring retainers, cam). Look for contact of the rocker to the top valve spring retainer.
2. Too light a valve spring. Floated a valve and kissed a piston.
3. Too much lift/ duration. Kissed a piston.
4. Timing is way off so valves and pistons are trying to occupy the same space at the same time. I think that goes against one of the laws of physics. I doubt it would run at all if timing was that far off.

 

[DoctorRons66]

I just pulled the valve covers off and just noticed that one of the pushrods was broken???

The engine has the stock A-code cam AND this problem happened before anybody even had the chance to tighten down the rocker arms on the newly installed push rods?????

Thanks,
Ron

 

[kevinstang]

I've seen motors that have sat along time end up with bent pushrods when they were turned over, either stuck valves, or stuck lifters seemed to be the culprit.When the engine rotated some parts didn't move so good....

 

[boss1]

I put in "rebuilt" 289 in my first mustang back in 1993. The idiots at the builders installed the cam gear off by 5 teeth. Bent all intake pushrods, broke all rocker arms. Engine started briefly. What a MESS! I should have rebuilt the motor myself. I ended up pulling the heads 4 times to finally get other problems corrected.

Rob

 

[DENVER]

Have it to over rev the RPM's once and this will cause bent push rods too.

 

[Art]

Take one 16 yr. old, add 3 Mountian Dews, one viewing of Smokey and the Bandit, 35 year old valvesprings, empty stretch of hiway = Bent pushrods