Rocker arm regrind

[ME 109]

Recently had reason to install some s/hand rockers on my RS.
These s/hand rockers were essentially unworn, other than these fine facets across the contact area. The cause of the facets is open for discussion.
I wasn't content to install these without resurfacing. My attemps to find one of the local engine reconditioners capable of performing this task proved futile.



So I made my own. I call it the 'dance floor.'





A squirt of oil on the plate, and a squirt down the rocker shaft bore, and the rocker skates on the plate quite nicely with two handed operation. The oil squirted into the bore of the rocker provides a small vacuum and significantly helps to keep the rocker 'planted' on its end, as it glides across the dance floor. I carefully lapped one end of each rocker to ensure no raised areas.
Two handed operation allows me to grind the full radius in one pass. The rocker starts is grind in front of the grinding wheel and moves around to the side of the wheel.
It was quite easy to develop a grind technique that provided a consistent pressure and travel speed. One of my old rockers was the dummy.
The grinding wheel is a basic 6" fine wheel.
Grinding the lobes? was a quick procedure with all four done in about fifteen minutes. Two or three light passes was sufficient with minimal removal of precious metal. Then I needed to deburr them and polish.

Hot off the press. The ground surface was better than appears in the photo. Radius surfaces are difficult to photograph!



Course black, to maroon, to green scotchbrite did the rest.

[Kurt in S.A.]

I thought there was a bit of hardening on these surfaces that can be lost by grinding. I understand the cam followers are that way...thought that the rockers would be too.

Kurt in S.A.

[ME 109]

I thought there was a bit of hardening on these surfaces that can be lost by grinding. I understand the cam followers are that way...thought that the rockers would be too.

Kurt in S.A.

Consensus on adv at least, seems to be that the whole tip is hardened, shown as the 'blued' end of the rocker arm.
The material removed in my grinding operation is insignificant when compared to the amount of wear evident on my original rockers, and they were quite pitted but still functioning ok.

I had the valve stem ends reground as well.

[Kurt in S.A.]

Consensus on adv at least

What do they know?

Kurt in S.A.

[Bamboo812]

Consensus on adv at least

What do they know?

Kurt in S.A.

[Major Softie]

Definitely needs something: hardfacing or case hardening would be safest. Hardening the whole arm the way the factory appears to have done, you run the risk of making the arm brittle if you don't have it just right.

[ME 109]

Definitely needs something: hardfacing or case hardening would be safest. Hardening the whole arm the way the factory appears to have done, you run the risk of making the arm brittle if you don't have it just right.

Case hardening would not be sufficient to cater for wear of the rocker contact surface. I think the rocker surface would shed flakes once case hardening had thinned/worn thru.
The fact that the wear surface can wear away without exposing/revealing the case hardening, leads me to think that thru hardening is the technique used by the manufacturer. Not sure if that would be heated and slow cooled, or a quench.
So through hardening would not be affected by very light grinding as not enough heat is generated.
I don't know this for sure.....

[robert]

You could tig weld a stellite hard face on the tip without weakening the rocker. Grinding an accurate radius might be tricky.
I think the later rockers are ok to reface as ME 109 posted.---RG

[Major Softie]

Definitely needs something: hardfacing or case hardening would be safest. Hardening the whole arm the way the factory appears to have done, you run the risk of making the arm brittle if you don't have it just right.

Case hardening would not be sufficient to cater for wear of the rocker contact surface. I think the rocker surface would shed flakes once case hardening had thinned/worn thru.
The fact that the wear surface can wear away without exposing/revealing the case hardening, leads me to think that thru hardening is the technique used by the manufacturer. Not sure if that would be heated and slow cooled, or a quench.
So through hardening would not be affected by very light grinding as not enough heat is generated.
I don't know this for sure.....

could be right. Testing will tell.

[daz]

Definitely needs something: hardfacing or case hardening would be safest. Hardening the whole arm the way the factory appears to have done, you run the risk of making the arm brittle if you don't have it just right.

Testing will tell.

Machine shop can do a Rockwell test to answer the question. Little cost.