Because stock components, in theory, don't require any adjustments. They're all machined to exact tolerances. The only time this becomes an issue is when things start moving around, like deck height, pushrod length, a machined head, etc.

 

Or a even a whole new head, like the OP is asking about.

 

I at least know they all have oil...when i built it i ran a drill motor on the oil pump for at least half an hour total time while rotating the crank a quarter turn every couple of minutes. I cant verify what happened inside but i made sure that all the rocker arms filled with oil. One of them, 4 or 5 shot higher than the rest...didn't understand what that meant but since they all had oil i marched on... I had a mech gauge plugged in and was running about 60 psi. This was while the engine was still on the build stand

 

Yeah like I said they might be ok for a while but also your vacuum will suffer if misadjusted. Best to do it.

 

So I finally got around to installing the rocker arms. I actually installed them twice to verify I was coming out to the same results. Here's what I did:

1. Rotate until I saw the intake pushrod rise and felt suction, then keep rotating until I felt compression.
2. Lightly rest a screwdriver on top of each piston and slowly crank until the screwdriver stopped moving up. I may have over-rotated a few degrees--how precisely do I need to hit TDC?
3. Install each rocker/pivot/bridge with Lucas assembly lube between: pushrod/rocker; rocker/pivot; rocker/valve.
4. Alternately finger tighten each bolt until I felt some resistance turning the pushrod.
5. Wiggle/jiggle/shake each rocker assembly. This would usually cause enough settling to cause the pushrod to spin freely again.
6. Finger tighten again until resistance in the pushrod was felt.
7. Wiggle/jiggle/shake and verify that the pushrod resistance was still there.
8. Mark the index.
9. Alternately tighten each bolt ~1/8 turn at a time until reaching 21 ft/lbs.

Cylinder 1 had both index marks hit at exactly 1 full turn both times. The rest of the cylinders came out like this:


It might be hard to tell, but the index mark for the rocker on the right is past one full turn, at about 2 o'clock.

For cylinders 2-6, the intake rocker was at or just under 1 full turn, while the exhaust rockers were always right around 2 o'clock after 1 full turn. FWIW, I replaced the cracked 0331 with a new Clearwater head & valves.

So my questions:
1. Do I need to get some shims?
1a. Is this what I need? https://hesco.us/products/30810/valv...-set-pnhesrask
1b. If I do need shims, do they have to be installed on both rockers (would be my guess) or just the rocker that is out of spec?
1c. Use the .030 shims?
2. Instead of (or before) shimming, should I just go ahead and buy new rockers/bridges/pivots and pushrods and see what the lash comes out to with those?
3. Is my (slight) lack of precision with TDC a possible culprit for the out of spec exhaust rockers?
4. Anything else I'm missing?

As always, any input is appreciated!

 

Without reading past the first few sentences, wrong. You're supposed to set it at base circle, not TDC.
Best also to do it cold engine then check after hot. I had assumed you read all the other posts.
Ill read on and see what else.
Yes, shims or custom pushrods. Shims are easier and quicker. As long as within spec you're ok.
Those is the link may work, but I used the ones from Crane Cams I think they were a bit smaller like 20 and 40
Yes you should shim both equally.
If you are going to buy new gear, absolutely you must use them when you check. Or do it over. It will make a difference.
Your lack of precision in setting TDC is an understatement, as stated you set at base circle which is much easier to find as its the part of the lobe where it isn't lifting.
Any 'out of spec' is simply the changes you made, head and new gasket, adjust to 20 to 60 and you're done. Kind of a trick to find the same shim on both i and e that will land both i and e within spec but I was able to.
If not you have to order a pushrod or two. Youre on the right track, sounds like you have the counting turns method concept. Hope that helps. If at first you dont succeed, why try again.

 

Wouldn't TDC compression stroke be right in the middle of the base circle for both intake and exhaust? Both valves are as closed as they ever will be at that point to allow the power stroke. Of course you would have to go to the same point for each cylinder in turn.

 

In the two posts from Dave1123 and CCKen (here and here for reference) that I linked to earlier in this thread, both explicitly state the need to set the index at TDC. I've been through a bunch of the other rocker arm related threads and this is the first I'm seeing base circle mentioned. Can someone clarify or explain this for me?

 

OOPS! I think I got confused! I was thinking you want to be on base circle and was imagining the lobe of the cam all the way up and thinking, top dead center . My bad! YES you want to cam to be on base circle. However you do that is fine. I think its not so critical that you be dead nuts on TDC to be on the cam base circle.
So yeah if you're satisfied with your measurements, a full turn would be too much if I recall. I know I had a couple of mine that were a turn, turn and a quarter. So some adjusting there. Again I apologize for my confusion. In my confusion I jumped to a wrong conclusion! Maybe I should delete that.

 

Ill follow that up by saying if you're finding that its moving when you move slightly around what you think is tdc, then you aren't on base circle. Base circle you should be able to rotate the crank quite a bit with no movement of the lifter. If you're trying to get BOTH valves on base circle at the same time? I don't think that is required. You're only checking one at a time.

 

Phew, thought I was losing my mind for a minute there. I can see how focusing so much on cams you could lock on to 'top of lobe' rather than 'top of stroke at the crank'. This is why we come here to hash it out. All straight now.

For OP, if you are not familiar with this deep into the engine, we aren't talking about TDC of the number one cylinder, which is what gets talked about almost all the time because most people don't go deeper than checking spark timing. In this case we are talking about going to TDC of the one cylinder you are working on so that both valves are fully closed as a result of the lifter being on the base circle part of the cam (the fat end of the egg shaped lobe). That way you are getting a true lash on those two valves. As pointed out, TDC isn't strictly necessary as the base circle covers at least 200 degrees of a street cam on any one lobe, and there is significant overlap of both closed to allow compression and power strokes. Lot's of people just watch the valves as they rotate the engine and a little after intake closes and exhaust was already closed, you are on the base circle. The only other thing to watch on this is after you do this on one cylinder, you have to watch the valves on the next cylinder as you rotate the engine so that now it is on all base circles. And so on through the whole engine. I think that is what you already described doing, but I figured I would put it out there just in case.

 

Well said. When I did mine I just used the serp belt looped around the crank to turn the crank. With the plugs out it's fairly easy. Never bothered with finding tdc, of any cylinder. Just rotate back and forth you can find that 200 degree flat spot pretty easily. Thanks for clarifying.

 

Yeah, I was finding TDC for each piston before torquing down the rockers.

Rockauto only has 2 sets of rockers in stock so I'm gonna bite the bullet and go to O'Reilly today. I also went ahead and ordered the .030/.060 shims from Hesco, but obviously they won't be here until next week at the earliest.

The .020/.040 shims would be preferable, but I haven't been able to find any via Google. 97grand, do you happen to have the part num or a link to where you got yours?

 

99179-1 for the Crane shims. But, they are the 30 and 60 also. And don't forget your assembly lube!

 

How did this work out for you?