Hole in my rocker!!

[midnight sun]

Went on a cruise today of about 125 miles.  A little more than half way I developed a pronounced miss.  Pulled wires until I found the dead cylinder.  #5.  Pulled the plug and it was wet.  Limped home and did a compression check and it came up ZERO on #5.  Pulled the valve cover and the push rod had punched a hole right through the rocker arm.

Anyone got a guess as to what happened or why? Chevy SB.

Thanks

[oiler]

Went on a cruise today of about 125 miles.  A little more than half way I developed a pronounced miss.  Pulled wires until I found the dead cylinder.  #5.  Pulled the plug and it was wet.  Limped home and did a compression check and it came up ZERO on #5.  Pulled the valve cover and the push rod had punched a hole right through the rocker arm.

Anyone got a guess as to what happened or why? Chevy SB.

Not the first time i've seen that, the higher mileage vortecs do it quite a bit.
Just wear is the only explanation I've got.
Several that I've fixed I've replaced all 16, I imagine a performance cam or higher than stock valve spring tension would cause this problem.
All the ones we get are stock though
Jeff

[32coupe]

Yeah, I agree. It is only wear and tear. Nothing to be worried about, it happens all the time. When I go on a long trip, I carry a spare rocker and a push rod in my tool kit. Just in case.

[Sean]

I've seen it happen before too. A buddy of mine has a couple setting on a shelf in his garage. One has a hole like what you are describing, the other has the whole end broken out of it.

Work hardening making them brittle maybe? Both of his came out of Dirt track engines that were running fairly high-lift Roller Cams. Maybe just poor quality control at the factory...

[phat46]

Went on a cruise today of about 125 miles.  A little more than half way I developed a pronounced miss.  Pulled wires until I found the dead cylinder.  #5.  Pulled the plug and it was wet.  Limped home and did a compression check and it came up ZERO on #5.  Pulled the valve cover and the push rod had punched a hole right through the rocker arm.

Anyone got a guess as to what happened or why? Chevy SB.

Thanks

I was under the impression that this was caused by the hole in the pushrod getting plugged and stopping the oil flow to the rocker. I found one in a small block once before it had worn through the rocker arm, but was seriously scored. The pushrod i removed wasn't plugged though, so who knows.....

[river1]

at what kind of mileage does this usually occur?

later jim

[EMSjunkie]

Work hardening making them brittle maybe? Both of his came out of Dirt track engines that were running fairly high-lift Roller Cams. Maybe just poor quality control at the factory...

Got a few myself in my "trophy" case from my dirt track days.
high lift and high rpms are tough on valve train componets.


Vance

[midnight sun]

Went on a cruise today of about 125 miles.  A little more than half way I developed a pronounced miss.  Pulled wires until I found the dead cylinder.  #5.  Pulled the plug and it was wet.  Limped home and did a compression check and it came up ZERO on #5.  Pulled the valve cover and the push rod had punched a hole right through the rocker arm.

Anyone got a guess as to what happened or why? Chevy SB.

Not the first time i've seen that, the higher mileage vortecs do it quite a bit.
Just wear is the only explanation I've got.
Several that I've fixed I've replaced all 16, I imagine a performance cam or higher than stock valve spring tension would cause this problem.
All the ones we get are stock though

I would agree if this engine were old and worn out.  It has less than 1000 miles on it.  Guess Ill go with the poor quality control.  Guess Ill be adding a few more parts to the old tool box too!

Thanks again.
Jeff

[kb426]

I had that happen to a 302  that was in a 38 chevy I used to own. It has been common in my knowledge.  I haven't found plugged pushrods, either. I put on a fresh rocker and went forward.  This motor had a fairly active life, though. Drag racing, street racing, former owner drank a little, etc.