Push rod through rocker

[413 belvedere]

Need help, this is the second time this has happened, first on #1 cylinder, push rod through exhaust rocker (stamped steel) and cup came out of lifter, intake push rod is bent. Installed both new lifters and push rods, started ran break in for lifters went for a drive, got on it hit about 5000 rpm and back fired and heard a noise again, pulled valve cover and #3 push rod through rocker, cup out of lifter and broke ball off intake pushrod and bent it, not cool. Have stealth heads and mother thumper cam, engine builder told me push rods are from a big block Chevy. Any ideas it is a 65 413

 

[413 belvedere]

2 ND time

 

[Mopars & Missiles]

No oil to rockers or too much spring??

 

[413 belvedere]

Lots of oil on the heads, the engine builder check the spring pressures, talked to him after first time he thought bad rocker and wasn't sure what caused the intake push rod to bend

 

[Ski 61701]

I agree lack of oil due to discolored tip. Whats going on with the push rod next to it. Looks like the tip is gone and the pushrod is split. Id pull the distribtor and turn it over while manually turning the oil pump drive to make sure youre getting oil up top. Also check for coil bind on the other valves pushrods might be a little long? How do the valve tips look on the other valves. Is the rub mark on the center of the stem or is it on either the inner or outer edge of the valve

 

[Mike67]

Just curious are those rocker used or brand new? Chinesium?
Spring pressure, installed height, geometry all correct?

 

[Ski 61701]

If memory serves me correctly when the valve is fully opened there needs to be a minimum of .060 space between the coils of the spring so they dont go solid on you and pop rocker arm cups

 

[413 belvedere]

I agree lack of oil due to discolored tip. Whats going on with the push rod next to it. Looks like the tip is gone and the pushrod is split. Id pull the distribtor and turn it over while manually turning the oil pump drive to make sure youre getting oil up top. Also check for coil bind on the other valves pushrods might be a little long? How do the valve tips look on the other valves. Is the rub mark on the center of the stem or is it on either the inner or outer edge of the valve

Tips look fine, discolor is probably from picture, yes intake broke the ball off and is bent. Checked coil bind and there is lots of room between coils, I'll have to look at top of valves but seemed OK, have a lot of oil on top of cylinder heads.

 

[413 belvedere]

Just curious are those rocker used or brand new? Chinesium?
Spring pressure, installed height, geometry all correct?

They are new, not sure of brand engine guy bought them, wondering if roller rockers are on my future

 

[413 belvedere]

1st time
Looks like lots of oil on rockers

 

[Fran Blacker]

Retainer bottoming on valve stem seal? Maybe you should crank up oil pressure by removing distributor and drive gear. I put a 318 shaft on wrong a did the same thing.

 

[Mike67]

Just a guess but I'm going say pushrod lengths...popping through a brand new rocker arm is no easy task....if they were 40 years old sure...

 

[MOPOWER871]

had this happen to me many moons ago on an exhaust rocker on my 383. If I'm not mistaken I replaced them with a direct connection stock style rockers that where beefed up around the ball.

 

[snakeoil24]

It looks like Pushrod turned blue like everyone said. But I am wondering if the lifter piston, spring assembly seized and cut off oil supply.

 

[413 belvedere]

This is pushrod from intake side first time

 

[dvw]

Common issue with used rockers when adding more spring pressure and lift. The ball of the pushrod is riding beyond its original travel creating a different wear pattern. This fatigues the rocker, breaking through. Then the pushrod catches in the hole and bends. How much spring pressure? Were the rockers used? How much lift? Are the pushrod ball ends the same diameter as the stock pushrods? I doubt if only one rocker would be missing oil with the stock set-up unless that feed hole in the shaft was plugged.
Doug

 

[khryslerkid]

You might already know,

The oil holes on the rocker shaft point down and toward the outside of the engine. (Toward valves)

The cup in the lifter should be compressed .040 to .060 when the valve is closed and on the back side of the cam lobe. Some will say .020 and that's what I have my adjustable rockers set for.
If compressed too much, bent pushrods and worse will happen. This is caused by a pushrod that is too long.

Stamped rockers are said to work up to .500 lift but in my opinion that's pushing it with stock stamped rockers.

I just looked up the specs on that cam, if the link provided is the same cam. Should be good with those rockers if new. I'd double check the pushrod lenth. JMO

https://m.summitracing.com/parts/cca-cl21-600-5

 

[Ski 61701]

That pushrod to me looks like a classic too long of pushrod especially with hydraulic lifters. Higher rpms more oil pressure. Hence the lifter goes into for lack of terms a solid lifter and the pushrod either bends or blows the cup on the rocker arm. Like mentioned earlier check for proper preloading of lifter. It might behoove you to get a couple of checking pushrods to set lifter preload and once that is done compare the lengths of checking prods to existing prods and see what the difference is. Id pull out the lifters in question and take them apart to make sure the internals werent damaged as a result of bending the rods

 

[413 belvedere]

I have the mother thumper cam, under .500 lift new rocker and push rods, set up by engine builder, builds drag race motors here in Washington, auburn area, will go back and talk to him again, but that is what I was kinda leaning to, to long push rods or wrong ball size

 

[miller]

engine builder told me push rods are from a big block Chevy.

Of course, some will disagree with this, though considering how a BB Mopar motor oils the top end, the push rods should not have oiling holes in the ends. Mopar push rods should be solid, or at least solid ends. The stamped rockers have a oiling hole at the cup, oils that end of the push rods, and travels down the outside of the push rod to the tappet.
I ordered push rods for my 440, and got those same kind of chevy rods...going back in, and will change them!
But, as said, also looks like push rod length comes into play, too. What kind of preload did you have on the tappets? If too much, tappets/push rods pretty much turn solid.