on second thought if Toyota has a part for the fix it must happen with the oem stuff.

'not quite'

If you look at pg EG1-30 that I posted earlier, you'll see the rocker shafts AND the rocker spacers. Hope that helps.

EDIT: I think your other factor is that the rocker arms are aluminum. IIRC, the ones on the 20R were steel.

Those two factory spacers aren't the issue for me. I moved the rockers around so unworn sides were against the towers. Didn't help.

The adjusters didn't line up perfectly with this assembly on the original head either, but none were out as far as the worst two on this head.

Some pictures are posted in a thread at yotatech: http://www.yotatech.com/f116/22r-rocker-arm-alignment-201856/

I have no experience with this. Is it normal for things to not line up very well until the head bolts are torqued and the engine rotated a few turns? I'm reluctant to ruin a head gasket to find out.

It seems to me that sitting on the locating dowels, the towers can't be very far away from their final positions, even without the head bolts in. They don't have much play on the dowels.

Today I put the rockers back in their original positions and gave each a .025" shim, with 2 shims on the two that were off almost .050". Now those two rocker pads aren't very centered on the cam lobes. Is it better to have the screws or the pads lined up?

This is becoming frustrating.

Is this issue seen only with non-oem heads?

>>>*Morning. I think this is the same one that I have been emailing back and forth for a few weeks now.

The issue is the rocker arms are cast, the rocker stands are cast, the head is also cast. Everything is machined and all mounting location are from the casting, we can see very quickly that moving from one part to another things vary.

The variance is builtin, with plus and minuses, and we see it all the time. It is nearly always harmless. Sometimes we see a situation where everything heads off one direction, this is called "stackup" in the industry, it used to be a terrible problem back in the old days. Neat things like a 427 Ford with a zero deck on one bank and .030" difference front to back on the other, the old 265" Chevy blocks that had the piston down on one bank and sticking out on the other. I have spent hours moving pushrods around on 390 Ford blocks, those came in 5 different lengths from the factory sometimes in the same engine.

Toyota is no different, and until the much more modern technology of today the factories did one heck of a lot of hand fitting.

99.9% of the time everything comes out within that plus or minus swing.

So.... we use a sheet of shim stock and modify slightly. In the case of the specs you give I would be thinking around .010" or so.

Personally, I would prefer as much of the rocker pad on the cam lobe as I can get and if the rocker arm adjustment screw never reaches the edge of the valve tippet, she will work just fine.

There is an old saying, "The man decides to sand his boat, but sands so well the boat won't float."

It's time to bolt her together and see how she runs.....*EB

Yep, that's me.

I guess I'll remove all the shims and use the rocker assembly as is.

I figured as long as I had the chance, why not spend a little extra effort to make things fit as they should, but in this case that doesn't seem possible.

Reminds me of the .50 caliber percussion pistol kit I received long ago. I planned to take my time building it and make a truly nice piece. Unfortunately, the factory had pre-drilled some holes in the stock and partially inletted a portion of where the lock fits. They did such a sloppy job I gave up any hope of crafting a well-fit gun. Those big, disgusting gaps couldn't be fixed.

>>>*From the series of discussion we have had, I think you are a lot like I am.

I always wanted to build an engine that is perfect. By "perfect", that means to me that every clearence at every point, every weight, every part is exact. With the best tooling available at my disposal, I would then be unable to find any variation, any flaw.

I have built or worked on literally thousands of engines, that is likely an understatement.

To date, I have never accomplished perfection. I have had people tell me there were, but I always knew. I have seen my work win races, and knew that at the moment they were the best of the bunch.

Yet always I knew there was a bore off 4 decimal points, one cylinder that was not quite the same, one port that did not flow perfectly with no way for my poor skills to correct.

The truth is that it drives me nuts....*LOL**...Over the years I have come to accept the fact that many other hands, many other pieces of machinery make all those parts, and they all come together at one point.

The job then is to check, double check, and make it all work. The vast majority of the time it does....*EB

This is my first time rebuilding an engine. I'm not seeking perfection. Maybe next time. <img src="/forums/images/graemlins/wink.gif" alt="" /> Landing within acceptable tolerances is good enough for this round. What's acceptable? What's ideal? In many instances the books don't say. This case of rocker alignment is one.

Something an experienced person can eyeball or give a turn or a wiggle to determine whether it's normal, unusual but ok, or a problem, leaves me scratching my head due to lack of experience.

To further digress, not being a machinist (though I wouldn't mind getting into the field), I have to farm out the most important work done in rebuilding an engine. I hand parts to the shop and get back whatever quality of work they've done. That's frustrating. I hate hiring people to do jobs because so many don't care. I mean for anything in general, not just machine shops.

One thing I've learned from this rebuild is using a good shop -- and good luck finding one in your area -- is of utmost importance.

Back to this rocker issue, I've found that the screws and pads line up about the same on my old 1986 head and cam as they do on the Engnbldr head with the 268 cam. Moving the rocker arms around to different positions doesn't make any difference, so it's not like a crooked rocker is the issue.

Both the old setup and the new seem to have noticeable misalignment between the #4 exhaust cam lobe and corresponding valve stem. With no shims, the screw is almost .050" off center while the pad rides slightly over the far side of the cam lobe. Shimming only moves the pad more out of whack.