Technical Very worn rocker ball pivot

1972 SBC 350 rebuilt 30,000 miles ago Was noticing a ticking after longer drives. Pulled valve cover a found a very loose rocker on #7

Any ideas on what went on here, what to check? Push rod is straight, oil hole clear. Stud is same height as others

 

Could be bad material but as it’s just the one I’d put it back together and use a priming tool on the oil pump and confirm you are getting oil feed to that rocker.

 

they never wear out that much.....Squirrel s gonna want to chime in on this one....my guess....that's the wrong one someone installed on a Monday morning after a bender...

 

I've never seen one worn that bad... Ever.
Did you use the original rockers and pivot balls for the rebuild? If you did... Did you keep them paired together or mix them up?

 

They were brand new comp cams roller tip rockers, balls nuts, pushrods, springs, etc cam and lifters. 30k miles ago

 

X3 No way it can wear out and be uniform.

Why so much oxidation on the top’s for only 30,000 miles?

 

Nut looked the same amount of threads as others. Stud is at the same height as his neighbors

 

I think that brownish color is how they come

 

Video of how I found it

rocker itself has little to no wear compared to his buddy next door

https://streamable.com/llzdgg

 

Should add I was having intermittent loss of power as well. It came and went. Thought it was ignition related. If I shut engine off and restarted it would get better sometimes. Could only do 55mph on the highway towing a 20ft camper at one point.

 

Either the pivot ball wasn't hardened properly from the manufacturer, or that rocker arm wasn't getting oiled enough.
You know you're going to have to dig deeper to see what damage the metal shavings did. I'm curious as to how the lifter looks.

 

I had a similar issue on a 283 recently. Pushrod clear, but barely little to no oil on three rockers.
@1971BB427 as well as a buddy who does many SBC’s suggested backing OFF the nut until it ticks. Run at fast idle for 15 minutes.
By golly, it worked! A trickle at first, then flowing like the others. Lifters weren’t oiling right for some reason. Saved pulling it down.
I had drilled out a steel rocker cover so that made it easy to watch.

 

I asked my shop, confirmed here on the HAMB, that’s not necessary for PR’s, arms, etc.
thread is a few years back, but no issues.

 

What does the rocker arm look like? Thin??

 

Pretty much identical in wear compared to the one next to it. Just shiny where the ball rubs. Need to take a real good look to tell. I weighed the two arms I took off and the trouble one actually weighed more by almost half a gram

 

If you know someone with a tester, rockwell the ball. If not rub a file on it. Could be soft

 

Used a fine file and it was somewhat easy to cut, somewhere around middle hardness of things I’ve filed

 

Personally I would try just replacing that one rocker ball and running it, keeping a close eye on it for changes in valve lash for a while.

 

wrong one

 

I'd suggest replacing the pivot ball and the rocker arm.
It seems something is going on there.

 

When you found the bad rocker/ball, was it bone dry? Were the others damp/soaked with oil?

Any chance that one rocker has some casting flash or whatever, blocking the oil from making it out of the pushrod?

Clearly, in my opinion, that one rocker appears to have been starved for oil for quite a long time ... either the oil isn't making its way out of the lifter and up the pushrod or the oil IS making it into the pushrod but not out onto the rocker.

I'd say you replace that rocker/ball then use a pre-oiler tool to see what is going on. As others have mentioned, play with the rocker adjustment while oiling.

 

Not hardened properly , like their cam lobes ?
Did you check the lift on the problem pushrods , check the valve stem for galling ?

 

Drag a file across a good one in a non-wear area, see how it compares to the bad one. I'd be somewhat concerned with where all that metal has gone, I'd cut open the filter for a look. You could do a couple oil changes after maybe 100 miles.

I would also pre oil the engine, make sure all the rockers are getting enough oil.

 

There should be some heat staining if it was starved for oil to the point of wearing that much material. The fact that it isn't file hard is a major red flag.
I deal with contact wear on metal parts and bearings all day. Frankly i would be blown away that it wore so perfectly without smearing/galling. Dang near looks like it was short to begin with, but your other indicators suggest otherwise. I'm curious as to how the rocker making surface looks and how much glitter is in the pan.

 

Only have a pic of the under side of the rocker right now. Will get a pic of the other side.

Rocker wasn’t dry but not dripping in oil either. The video I posted is the only pic I have before I took it apart. The hole in the bad ball pivot was very sharp around the edges.

Will drain oil and check it. I had just did an oil change before the 6 hour drive that I started having power issues but I did have ticking before that trip that I thought was an exhaust leak.

Sent comp cams a facebook message and all they said was to send an email (5-8 day response time) and to check valve lash and spring pressure. Tried calling but gave up after an hour on hold

 

Oh them things. I tried those once, took them off after a week and went total roller rockers.

 

Hard to believe it could wear that smoothly and evenly. I'll throw in with the wrong part suggestions.

 

I don’t have a definite answer as to what happened but I do know a bit about sintered metal, I worked with that material for 20 years at GM’s locomotive plant. When powder metal parts were suggested to top management in Detroit they immediately said no way, that stuff is OK for light duty applications but it will never survive in a locomotive. Electro-Motive Division’s process engineering department was looking to eliminate some forgings and castings and a lot of the machining that was needed. The answer was raising the sintering temperature from 2050 F to 2250 F and increasing the time in the high heat zone of the electrically heated furnace, the result was superior parts.
We were pressing to 7 grams per cubic centimeter with a press capable of exerting 40 T per square inch.
Sintered metal does have some porosity (think Oil-Lite bushings, although those are pressed to a much lower density) but it is durable for many applications and depending on the part it eliminates all machining. You are pressing on the vertical plane so a horizontal hole will need secondary machining for example.
Rocker arm balls are one example of a good application for PM, press them, sinter, deburr and ship ‘em. As to what happened to the OP’s rocker ball the only possibility I can think of is the die cavity somehow did not get completely filled (causing lower density) resulting in a weaker part. I did the file test on a high temperature sintered part we produced at EMD 40 years ago and it was no different that an old rocker ball I checked. Easy to nick but certainly durable for it’s intended application.
We did not Rockwell test our PM parts, we checked production on a Tunius-Olsen tensile tester, the part was loaded hydraulically and the tell-tale needle gave a direct readout of the load it took for the part to fail. The T-O machine can test by loading until the part yields, or pull a part held in jaws until it yields.
If the rocker looks OK I’d put another ball in, even a nice used smooth one and run it.

 

Here's a GM part that's clearly a lot shallower than your Comp Cams set.

 

Here’s some pictures. The bad rocker is so close in condition to the good one I can barely tell which is which. The marks on the ball pivots are from my filing