Valve Lever Misalignment

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Jim Becker
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Re: Valve Lever Misalignment

Postby Jim Becker » Tue Mar 02, 2021 4:47 pm

I would try swapping same-numbered parts to different positions to see if the alignment improves. After doing the best I could by that method, I would add shims to get contact across the full end of the valve stems. They do not have to be centered across the contact surfaces of the rockers. I would not try bending the rockers as it may disturb the orientation of the curved surfaces of the rockers, leading to an uneven contact with the valves.

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Re: Valve Lever Misalignment

Postby arlen » Tue Mar 02, 2021 4:52 pm

Jim Becker wrote:I would try swapping same-numbered parts to different positions to see if the alignment improves. After doing the best I could by that method, I would add shims to get contact across the full end of the valve stems. They do not have to be centered across the contact surfaces of the rockers. I would not try bending the rockers as it may disturb the orientation of the curved surfaces of the rockers, leading to an uneven contact with the valves.

:thanx:

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Re: Valve Lever Misalignment

Postby arlen » Tue Mar 02, 2021 10:56 pm

Jim Becker wrote:I would try swapping same-numbered parts to different positions to see if the alignment improves. After doing the best I could by that method, I would add shims to get contact across the full end of the valve stems. They do not have to be centered across the contact surfaces of the rockers. I would not try bending the rockers as it may disturb the orientation of the curved surfaces of the rockers, leading to an uneven contact with the valves.


I swapped 4 of them, and made 2 of them much better, and didn’t make any worse.
I found these shims on Amazon. There is a couple that could use .030 to .060 to make them darn near perfect.
https://www.amazon.com/gp/product/B004K ... UTF8&psc=1

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Re: Valve Lever Misalignment

Postby Gary Dotson » Wed Mar 03, 2021 8:10 am

Those look like they should do the job nicely. The extras are a welcome addition to the parts bin, probably come in handy, down the road.

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Re: Valve Lever Misalignment

Postby arlen » Wed Mar 03, 2021 10:44 am

Gary Dotson wrote:Those look like they should do the job nicely. The extras are a welcome addition to the parts bin, probably come in handy, down the road.

One thought I had, is shimming them .030 or .060 going to cause an issue with the push rods? It looks like there isn't much room for them to move in the tappets side to side, and it looks like the contact area with the tappets are flat, so I suppose they can't tolerate much of an angle. I suppose I will just have to make the final shimming decisions when the head is installed. Maybe I'll get lucky the shims will actually improve the fit with the pushrods too.

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Re: Valve Lever Misalignment

Postby SamsFarm » Wed Mar 03, 2021 11:23 am

The push rods should be captured in the lifters, and have a cupped end to capture the ball end stud on the rocker arms.

A .030" shim shifting your rocker arms sideways with a 10" push rod is gonna shift the angle by .171 degree!

Very trivial amount! (As long as they dont rub in the head or block!)

(10 inch is just a guess on the push rod length!) :)
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Re: Valve Lever Misalignment

Postby SamsFarm » Wed Mar 03, 2021 11:55 am

Speaking of those stainless shims on amazon.

Generally stainless is soft and not a good wear surface.

If it was me, I would want to use a precision ground, hardened shim.
Something that might be more available at your local bearing supply house or maybe mcmaster carr or msc!

Does it matter, you decide! :)
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Re: Valve Lever Misalignment

Postby arlen » Wed Mar 03, 2021 10:58 pm

SamsFarm wrote:The push rods should be captured in the lifters, and have a cupped end to capture the ball end stud on the rocker arms.

A .030" shim shifting your rocker arms sideways with a 10" push rod is gonna shift the angle by .171 degree!

Very trivial amount! (As long as they dont rub in the head or block!)

(10 inch is just a guess on the push rod length!) :)

I see what you mean. For some reason I thought the tappet end of the push rod was flat, but I see it has a radius and can tolerate a bit of an angle.

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Re: Valve Lever Misalignment

Postby Gary Dotson » Thu Mar 04, 2021 8:24 am

My only concern, with the push rods, would be clearance where they pass through the head. I wouldn't worry about wear on your shims, there is virtually no side load on the rocker, you never see wear on the side of a rocker. Use them and forget about it!

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172 Runner Planter
53 Fertilizer
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Re: Valve Lever Misalignment

Postby SamsFarm » Thu Mar 04, 2021 9:29 am

The rocker arms are captured on the rocker arm shaft and shimming one sideways will not change the angle of their operation.

The change in angle will be the push rod.

The ball tips on the rocker arm adjusting studs are made to be forgiving of a wee bit of angle.

Since the radius is parallel with the rocker arm shaft, that is probably why IH was not too concerned if they were off a bit!


There is a cut-away view of the engine in the A & B service manual (in the manual section if you dont have a hard copy), and if you look close, you can see that the push rods are angled.

Dont forget that the radius on the rocker arm tips that contact the valves is hardened, and if anyone thinks of heating their rocker arms and bending them, you risk the chance of softening the tips which would lead to them wearing prematurely!
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