VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Noisy rocker arm shaft(s) in a 216?

The 3836114 rocker arm stands are from a 1954 or later 235 engine. I have no demensions for them. The book always listed a different support for a 1950 and up 235 engine - I do not know the difference.
In 1954 the rocker arm shafts had the smaller bolt holes and did not use the sholdered bolts. Also the shaft had a slight flat spot on the bottom. After 1955 if you purchased new rocker arm shafts for a 1940 and up you got the late style and had to use the non-sholdered bolts.
Seeing you checked out the demensions I don't think your problem is in this area.

My question is about the "short lifters with the concave tops".
The 1939 lifter had a tall body and had no cap on top. The push rod sat in the floor of the lifter only the thickness of the metal between the push rod and the camshaft.
The 1940 and up 216 lifter had a simular body but the push rod sat on top of the lifter and the lifter had a little extension on top about 1/4" or more above the main body.
The 1956 and up truck solid lifter did not have the extension on top and the push rod sat almost on top of the lifter - it had (the lifter) only a little dish on top for the push rod. Looked alsmost like a hydraulic lifter. It was the same height as a hydraulic lifter and used a push rod that was 11 13/32" long.

It is not necessary to do anything with the rocker arm adjustiing screws when tightening dow the rocker arm assembly. The camshaft lobes that are up will push the valves open as you tighten down the rocker are shaft bolts. The rockers arms then WILL require a fine tuning adjustment for valve gap.

Having the later type rocker arm shafts is no problem as long as the non-sholdered bolts are used. I don't think the supports are the problem. The problem lies in either the push rods or the lifters.
I appears that at some point a rocker arm assembly from a 1956 and up 235 engine was installed. Not sure as to what lifters were used.

If you send me your email address I will send pictures of lifters.

37Blue
By valves that are open is that there is always some valves that are meant to be opened by the camshaft. If these valves are closed the cam lobe lift will have to go somewhere and holding the rocker shaft off the head is the result. 3/16" would be somewhere close the cam lift height.
I dont have access to a open engine or I would post photos to help explain.
Tony

Thanks, Tony. I understand now. I worked today on this and had some help so Old Blue may be closer to being back on the road soon.

Here is what we think is/was the problem with the rocker arm assembly not seating correctly, which resulted in about a .25" gap etc.

As may be recalled I have assemblies from a '40 version of the 216 I am trying to use on a '39 version. Both engines have been rebuilt or worked on otherwise by previous owners. Over time some parts were changed as necessary, so neither engine is completely "stock".

I previously measured the stands and checked casting numbers. All seemed fine. BUT,in measuring the stands I was only measuring the length. Part of the problem appears to be that the stands are in fact different in dimension from the bottom of the stands to the bottom of the hole the rocker arm shaft slides through. The difference is about .15". Another issue is there appears to be valve recession of about .10".

Instead of only needing to use the rocker arms and valve lifters I need to also use the stands from the donor engine. This addresses part of the gap problem.

I want to avoid, at least for as long possible, pulling the cylinder head to verify this and potentially installing valve seats. I am considering using shims. It seems that large washers measure .10". By slipping a washer under each stand and bolting the assembly in place the valves can be adjusted.
This MAY be an acceptable solution given the truck typically gets less than 500 miles per year and total engine time is less than 25 hours per year.

Any thoughts?

If the distance between the head face of the stands and shaft centre are different it will cause the problem you describe. Could you use the longer stands and not need the washer. While the washer idea will work and rarely be seen by anyone but you it isnt really a proper repair.

If there is a difference in rocker cover depths the rockers may now contact the shallow cover after lifting them that far.

Tony

The longer stands would be used to remedy part of the gap problem. Even with the the longer stands there is a .10" gap. The washers (shims) would address what is suspected to be valve recession. I agree the "solution" would not be a proper repair. It certainly is not the preferred option. I am wanting to postpone replacing, the engine for as long as possible. There are are other issues with the engine. The block has a small crack. I have been monitoring that for some time.

The range of valve adjustment with the rocker arms adjusting screws would take care of at least .100" or more either way. (up or down)

I agree. But, for the adjusting screws on two valves only two threads remain for final adjustment. That seems to be barely enough for a long term solution.

I think I now understand why the previous owner didn't try to install the correct arms.

An engine replacement seems more and more likely, given the cracked block and patchwork needed to keep this one going over the long term.

I've taken digital photos and will post a link for these when I get time.

37Blue

The head could have the incorrect length valves .

Wow! I hadn't considered that possibility. Given the variety of incorrect year parts encountered thus far, the incorrect length valves would not surprise me. If the engine was "rebuilt" by the previous owner I would think the valves were reground/replaced and new valve seats installed; but maybe not.
If it wasn't for the fun I'm having in learning about all this I'd probably can that engine now.

A sequence of photos and captions of Old Blue's rocker arm saga are posted at the link shown below.

http://s886.photobucket.com/albums/ac64/37Blue/

Great News!!!!
Old Blue is back on the road and she sounds GREAT!!!! The valves were adjusted and cover replaced. I took her on a 45 mile cruise for a little more than an hour today. She purred like a kitten and seemed to have added zip. I think, in looking back, that the valves were not adjusted correctly all along.

Thanks to all that offered guidance and suggestions.

This will be the last post in the Saga of Old Blue's Noisey Rocker Arms. It was a worthwhile learning experience.

Are you saying that the valves were not adjusted properly and that was the problem all along ???????

No.
The problem(s) were as described earlier. The valve adjustment was another unrelated and previously unrecognized issue.