Rockers - how bad is too bad?

B

bobdobbs

New member
I took my rocker shaft apart and it looks like there were some oiling issues in the top end. The head is getting rebuilt at the machinist's right now, so it's a good time to decide what to do about this. If it matters, I'm getting 75 thou shaved off of the head. Coupled with the aftermarket gasket, this should net a 50 thou decrease in distance. My understanding is that the hydro lifters can compensate for this.

I just put the timing cover and oil pan back on, so swapping the camshaft is out of the question. :banghead:

Option 1: File rocker pads down and use them.
Option 2: Start replacing parts.

The issue is where to mount the old parts to the new. New lifters on old cam? New rockers on old pushrods? New rockers and pushrods on old lifters?

Pictures here:
http://s711.photobucket.com/user/ctcobra/library/mav

Cody
76 maverick L6-250
 
:unsure: Well if the lifters are still in good condistion and you kept them in order so they each go back on the same cam lobe then there's no real need to replace them. But if they show signs of excessive wear on the bottoms then it would be better to replace them. Yes for sure since your rebuilding the head you should also do something about the condistion of those rocker pads. If you have the ability to true up the pads that would be about the minimum to do. If the rocker shaft and rocker bushings have excessive play then maybe hunt for a better set or get a rebuilt / new set. Good luck :nod:
 
Hi,X2 keeping old lifters in order if you plan to re use them. If the bottom of the lifters are dished they are worn. We used to clean the shaft with scotch brite pads and solvent, and sometimes lightly hone the rocker arms just to clean them up. I would lightly dress the tip of the rocker arm, maybe try a sharpening stone and file. Check your pushrods for the mohawk. From the looks of the rocker arm I would guess some of the push rod need to be replaced. Good luck
 
Thanks 4 da pic Cody
bobdobbs":10qi90ju said:
Option 1: File rocker pads down and use them.
Option 2: Start replacing parts.
The issue is where to mount the old parts to the new. New lifters on old cam? New rockers on old pushrods? New rockers and pushrods on old lifters?
Click to expand...
bubs: “…something about the condition of those rocker pads. If you have the ability to true up the pads that would be about the minimum to do. If the rocker shaft and rocker bushings…”

Bron: “…lightly dress the tip of the rocker arm…”

the shiny part of the rocker 'fingers' looks a lill 'off center". Would correcting that (as above) be important?
Do U think some washers under the pedestals would increase performance even w/the "adjustable"?

I re-used my shaft after a lill emery cloth smoothing. Looked a lill worse than yours. Slipped thru pedestals easier.
 
I'll post more pictures, and grab the pushrods and take pictures of them.

I'd like to just put in a new rocker assembly, but I don't know if the new rockers would mate with the used pushrods, or suffer accelerated wear?

Say I put in a new rocker assembly and pushrods too: will the new pushrods mate with the old lifters?

Does that make sense?
 
Hi, if I was putting in a new rocker shaft assembly it would be an adjustable one which means matching cup style pushrods, with a 1.6 ratio. You need the Falcon Six Handbook. Good luck
 
Pushrods don't really 'mate' to anything...
Lifters will wear into their lobe on the cam, when you replace just the lifters then those lifters will wear into the cam. It's not like it's something that can only be matched together once. Obviously if you have a lifter that is eating the cam lobe then yes you are going to have to replace the cam as well as the lifters, but if you have a lifter that's bypassing or something, the procedure is to just replace the lifter. Not the whole cam and all the lifters and everything attached to everything. If you just need to replace the rockers then replace them. Use some ZDDP additive and you'll be fine.
It's just two pieces of metal moving together, it's not rocket science.
 
I'm not sure if you pulled the lifters yet, but if they are worn concave, toss them and get new ones. New lifters will be slightly convex, not flat. That allows the cam lobe to rotate them as they are lifted. As long as the cam lobes aren't worn out, that's the best route. Just break them in the same way you would a new cam.

I would really consider replacing the rockers and rocker shaft. You could file the pads but there's a curve that you need to follow. It's not flat. There also looks like several thousandths wear in the shaft and the rocker bushings are also probably worn. When you start stacking it all up, the assembly will be kind of sloppy. The wear on the shaft coupled with the wear on the rockers could allow too much oil to leak past and starve the front rockers that are the farthest away from the oiling pedestal in the rear. It could also be noisy, even with hydraulic lifters.

All that said, you could toss all the parts back in just as they are. The engine will run. It will probably run better, just by virtue of being cleaned up. But to get it to run really well for a long time, you need to replace some parts, in my opinion - lifters, rockers, rocker shaft, pushrods.
 
What's the best way to inspect the cam shaft for replacement (I wouldn't re machine as the cost would run past a new purchase)?

It seems like the only part of the assembly you've left out in that list
 
MustangSix":14ig1mat said:
I'm not sure if you pulled the lifters yet, but if they are worn concave, toss them and get new ones. New lifters will be slightly convex, not flat. That allows the cam lobe to rotate them as they are lifted. As long as the cam lobes aren't worn out, that's the best route. Just break them in the same way you would a new cam.

I would really consider replacing the rockers and rocker shaft. You could file the pads but there's a curve that you need to follow. It's not flat. There also looks like several thousandths wear in the shaft and the rocker bushings are also probably worn. When you start stacking it all up, the assembly will be kind of sloppy. The wear on the shaft coupled with the wear on the rockers could allow too much oil to leak past and starve the front rockers that are the farthest away from the oiling pedestal in the rear. It could also be noisy, even with hydraulic lifters.

All that said, you could toss all the parts back in just as they are. The engine will run. It will probably run better, just by virtue of being cleaned up. But to get it to run really well for a long time, you need to replace some parts, in my opinion - lifters, rockers, rocker shaft, pushrods.
Click to expand...

I think that's where I'm headed: New lifters, ball&cup pushrods, and an adjustable 1.6 rocker assembly. I've shaved 0.075 thousandths off the head and put in 302 springs. The Ford Falcon manual says with a 1.6 rocker assy I'll gain "just less than 0.030 more lift". Is there a math formula that I can use to verify I won't run into any coil bind?
 
Technically, yes. Multiply the cam lift by the rocker ratio and compare that to the spring install height and bind point.

Should always check before running. I've got a 1.65 ratio setup and dampened springs. I had my machinist check to .500 lift, which is beyond where I'll end up in the end.
 
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