[kk68]

Before tearing this down, anyone have a educated guess as to what’s causing this rocker to be pushed up higher than normal? Stuck lifter?

[400 Lemans]

My guess is the wire retainer clip has come out from above the plunger on lifter. Does it miss, like its running on 7 cylinders?

[steve25]

X2 with the above.
This takes place at times when you rev the motor too high for the spring pressure and float a valve .
If you pull off all of those 4 rockers , the 4 studs and the guide plate you can shine a brite light down in the lifter valley and see the the plunger clip is gone and the plunger is out near the top of the lifter body.

If your lucky the Clip will still be in the lifter valley like I had happen to me once.

[Joe's Garage]

We had this happen just once and the engine didn't really 'miss', it just ran a little rougher, like that cylinder was down on power.

And I would point out that your are REALLY LUCKY that you caught it when you did, before the lifter disassembled itself completely inside your engine.

More than likely no damage is done done except the lifter. (fingers crossed)

Good luck!

[PAUL K]

It looks like that valve spring is broken.... Take a closer look at that first. I can't tell for sure from that picture. It might just be reflection also.

[1968GTO421]

I generally replace those cheap little wire retainers with these C clips available at most industrial supply houses. Works real well. (Same thing, different size, retains floating piston pins.)

https://www.fastenal.com/product?query=1168045&fsi=1

[steve25]

Also to me the other thing that looks like is going on in that photo is that the normal valve tip contact point of the rocker seems to be well off the tip of the valve towards the exh side and the ball socket of the rocker looks to be darn close to riding on the valve spring oil shield.

["QUICK-SILVER"]

Is the push rod end of that rocker arm made taller than the others?

Kinda looks like it in the pic.

What lift cam this engine got in it?

Is the rocker still high if you bump the engine over so the lifter isn't up on a lobe?

Clay

[HWYSTR455]

The wear mark on the pushrod is roughly in the same location on all the other pushrods, so I'm thinking it's possible a rocker arm tolerance/variance or pushrod ball is an issue.

Swap the rocker to another location and see if it's the same. That will eliminate the pushrod and lifter as the problem.

Worse-case scenario, the valve sunk into the valve seat/head. When were the heads done, and what was done?

.

[67Fbird]

Originally Posted by steve25

X2 with the above.
This takes place at times when you rev the motor too high for the spring pressure and float a valve .
If you pull off all of those 4 rockers , the 4 studs and the guide plate you can shine a brite light down in the lifter valley and see the the plunger clip is gone and the plunger is out near the top of the lifter body.

If your lucky the Clip will still be in the lifter valley like I had happen to me once.

NOTE: standard pontiac lifters can benefit from 11/16 internal lock rings

https://www.tractorsupply.com/tsc/pr...retaining-ring

[kk68]

Thanks for all the help. I'll report back with what I find after I've had a chance to investigate further.

[NeighborsComplaint]

Originally Posted by PAUL K

It looks like that valve spring is broken.... Take a closer look at that first. I can't tell for sure from that picture. It might just be reflection also.

Yeah, the stackup on that 1st spring doesn't look right.

[Richie Hoffman]

if they are aftermarket rockers check were pushrod goes in rocker just had that problem rockers were cast different had to order 3 sets to make up 16

[steve25]

Yes, I have seen that with SBC aluminum rockers , but stamped steel rockers like he is using would seem like a far stretch that a push rod socket would be out of place .

[389]

When installing new lifters, I take them all apart, clean them, fill them with oil and put a circle clip on instead of the little hat clip.