Rocker Revival

[240260280z]

Some pics of cleaning up a rocker.

Here is what a "good" used rocker looks like.

It has had a lot of quality time with the cam and polished to shine with smooth undulations in the surface.

Not much surface for holding oil when so shiny like chrome.

Here are the 3 best rockers out of a used set of 12. I refreshed the worst of the 3 by using a flat slab of marble and sand paper.

I measured variance to be 0.001" across the surface's peak. The front (engine side) is where the drop off is.

It was interesting that simply placing the rocker on the flat surface gave the results; so it seems the machining surfaces are parallel (see below) and registered off the bottom of the rocker.

Pulling the rocker towards me with 500, 600 then 800 grit accomplished the following:

I did the same for the lash pad side.

I took off the ridge and the surface's peak was measured to be less than a thou. across the surface.

The ridge (the silver square is actually indented) took a while at 500 grit to remove.

To finish, I washed thoroughly with detergent to remove all abrasive then coated with Clevite 77 break-in lube.

Edited April 14, 2015 by Blue

[siteunseen]

You mentioned shiny not holding oil. When I got my rockers and cam reground I noticed a mildly rougher finish on both. Now I know why. They will smooth themselves together.

Edited April 14, 2015 by siteunseen

[grannyknot]

Blue do think I should do the same 500,600, 800 grit paper on the rocker you are sending me or just use it as is?

[Captain Obvious]

Blue, Those look great.

 

Any considerations about surface treatment of the contacting surfaces? Do you know if there was any special treatments done that you might be wearing through? I thought I saw a thread on hybrid that talked about that sort of thing, but I can't find it. My search-foo is weak,

[240260280z]

Blue do think I should do the same 500,600, 800 grit paper on the rocker you are sending me or just use it as is?

I'm sending you all three

[240260280z]

Blue, Those look great.

 

Any considerations about surface treatment of the contacting surfaces? Do you know if there was any special treatments done that you might be wearing through? I thought I saw a thread on hybrid that talked about that sort of thing, but I can't find it. My search-foo is weak,

I'd like to surface harden but I'm not sure how much or how to. Some sort of eddy current device would be nice.

I am guessing the inserted pad in the rocker is of a special alloy that helps.

What ever was on the small surface was worn off or compressed at least 0.002"

btw thanks for saying nice work... from you that means a lot for machined stuff!

[rossiz]

nice! i thought about trying that on mine when i was in the middle of my rocker dilemma, but went with delta. yours look just as good. it would be interesting to see how they wipe on the cam - cover in sharpie and see what kind of pattern you get. would be a good measure of surface trueness in relation to the cam.

[grannyknot]

I'm sending you all three

That sounds great! But which one do you think I should use?

[240260280z]

Have fun prepping the other two and use the best. If you want to drive fast just use the prepped one when it arrives.

[240260280z]

2004 instruction from the great Norm on Zcar.com ~2004

Directions on how to resurface rocker arms

For those that would like to save some money and reuse your old Nissan rocker arms when installing new cams, I have posted the complete instructions below.

If you are not a GOOD mechanic then you may be better off having a professional resurface your arms for you.

Start with a flat surface and about five different grades of emery paper and a bottle of WD40 or liquid wrench and a bottle of Brake Cleaner.

Start with 180 grit emery paper placed on a hard EVEN flat surface and liberally spray down the paper with liquid wrench or WD40 and then work the unworn raised end edges of the rocker arm pad down in a sideways motion until the edges are even with the rest of the rocker arm pad. DON'T go to far and create a dip. Check often on your progress and stop when the old ridge is even with the worn part of the contact pad .

Use a different FRESH part of the emery paper EACH TIME you start with a different rocker arm.

This will ensure uniformity.

Do all twelve rocker arms in this fashion and spray all the rocker arms off completely with Brake cleaner to remove all emery grit and then switch to 220 grit sprayed liberally with liquid wrench or WD40.

Next, in a rolling motion pull the rocker arm towards you across the 220 grit being sure that the entire surface of the rocker arm contact pad touches the emery paper at some time during the rolling motion.DO NOT go back and forth.Start at the same end each time and pull the rocker arm towards you.

Use a different FRESH part of the emery paper EACH TIME you start with a different rocker arm.

This will ensure uniformity.

After a number of pulls after which all 12 rocker arm pad contact surfaces look new and even across the entire surface, switch to 320 grit and repeat cycle and then switch to 400 grit and finish off with 600 grit.

Note: sometimes there will be pin holes on the rocker arm contact surfaces form past usage. DO NOT worry about getting these out as they will not harm the cam.

Keep the emery paper sprayed down with liquid wrench or WD40 at all times and use a different FRESH part of the emery paper EACH TIME you start with a different rocker arm.

This will ensure uniformity.

.

Also, smooth the rocker arm tips where they contact the lash pads in the same manner as described for the rocker arm contact patch and then fully clean the rocker arms with Brake cleaner until NO trace of grit remains anywhere!

Smooth the sharp lengthwise edges of the rocker arm contact patch and the rocker arm tip that rides on the lash pad to eliminate stress risers so that there is a very , very slight rolled edge. This is done in the same manner as described above but while holding the arm at a 45 degree angle and is done just to take the sharp edge off. Don't let the now smooth rocker arm contact patch be marred.

MAKE certain you FULLY clean EVERY little piece of grit from the rocker arms.Get a Bottle of Brake cleaner and hold the rocker lengthwise and soak it down until it is 100% clean.

Failure to FULLY clean ALL GRIT from EVERY nook and cranny will result in cam damage!

I used this exact method when I installed my new Crane cam over 80,000 miles ago and both cam and rocker arms still look good today.Make sure and use the cam break in lube and directions whenever installing a new cam.

BTW, do not use Crane rocker arms as they are WAY inferior to Nissan and can break in half under extreme rpm.I know this from personal experience!

Later,norm

[Captain Obvious]

it's clear from the fact they built a multiple alloy assembly for the rockers that they were trying to utilize properties of different materials in different areas. I don't have rockers laying loose anymore to inspect, but I suspect the pad that contacts the cam was brazed into place similar to how they attach carbide bits to a saw blade. I also suspect it's properties run pretty much the same through the whole pad. By that, I mean I bet a couple thousandths down into it is pretty much the same as at the original surface.
 

If there were issues, I would expect them to surface (get it?) at the lash pad end. I believe surface hardening runs deeper than .001" so if they did something like that at the factory, you shouldn't be through it at just .001. And there's no way I would try to home heat treat those things! I've done a little hardening with my oxy-acetylene torch and a can of quench oil, but there's no way I'd try it on something like that! Not nearly consistent or predictable enough.

 

As for how good the workmanship looks... I've heard stories of the training of the old school European machinists and their apprentice days. One of the stories is that some apprentices spent their first year or two doing nothing other than hand filing. Maybe not even with a goal in mind other than to spend time filing. 

 

I'm clearly still an apprentice and with that in mind, I just spent a bunch of time hand filing a Z project yesterday. Turned out fantastic...
 

[Zed Head]

A note from the past, and a thought:

 

the first Nissan rocker arms for this application were chrome plated.  Very, very smooth, I assume.   So, surface roughness of any kind may not be desirable.  The roughness for cylinders is more to get the two surfaces, cylinder and ring, matched for sealing purposes, not long-term wear.  I think.

 

And since you have fresh metal now, assuming that the ZDDP basics are correct, you should treat that new rocker pad surface with ZDDP-containing break-in oil or break-in paste.  To rebuild that critical "anti-wear" layer.  The ZDDP action is at the molecular level, much, much finer than any roughness level you could decide to shoot for.  

 

I'd go for a super smooth surface with ZDDP-containing paste and oil for break-in.  Of reputable brand.  Based on the stuff I just packed n to my brain over the last few days.