'96 vortec 454 push rod broken after head job
 

We have broken about 7 intake push rods, while idleing after installing rebuilt heads. The dealer shows no service bulletins. Any ideas?

Lynn

How close are the springs to coil bind at max lift? Also retainers may be hitting tops of guides.

I saw this happen once with Rhodes lifters, engine would idle all day long soon as it was revved up cam key would shear off. Not a bent pushrod but maybe pushrods are the "fuse" this time.


Are you using the correct lifter and pushrod combination?
Seems to me the Vortec big blocks use different lifter & different pushrod length than the earlier gen 4 big blocks.

454 broken push rod
 

Greg, I'll ck with machine shop. He might not realize this is a vortec, or there is a difference. Thanks for the tip. I'll let you know how it goes.

Lynn

Also check valve stem to guide clearance. Too tight will stick valve and bend pushrods. BBC's need a little extra clearance.. Been there.

Dhevy 454 broken push rods.
 

Thanks, the machine shop assembled the heads and they installed a "bearing" as they call it below the spring. Perhaps this has something to do with it. I'll check back with them. Will update the site when I know.

Thanks again.

lm