SV345 - 5 bolt rocker assembly on a 9 bolt head

Discussion in 'General IH Tech' started by trobbl, Sep 19, 2020.


  1. trobbl

    trobbl Farmall Cub

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    I'm working on a spare 345 I acquired cheap. I plan to use this in my pickup while my original engine is being rebuilt. I've had it running and it seems to run good without any funny noises. My plan is to clean the spare up and put in new gaskets and seals where needed. I took the valve covers off and noticed some very sloppy rocker arms. Upon further inspection, I discovered the driver side rocker shaft is considerable worn and the passenger side is even worse. I put a caliper on it and found the worst part is worn by about 50 thousandths. The oil groves on the rockers on that side are completely gone!

    I was able to score a couple used rocker assemblies from the junk yard for $40 each. They are in great shape, but are a different design than the old ones. My old assembly has welded rockers and 9 bolts. The junk yard pair are newer with boat style rockers and 5 bolts. I grabbed the push rods too since they are different than the ones used for the welded rockers. My plan is to use the 5 bolt assembly and plug 4 of the unused mounting holes in the head using short bolts. What do you think? Any known issues with this swap?

    I posted a video on my Youtube channel including my junk yard trip some of you might find interesting.

    Worn out rocker shaft - Yikes! 50 thou
    IMG_0458.JPG IMG_0459.JPG

    Rocker arm with the oil groves completely worn down to nothing. IMG_0460.JPG
    Old assembly - welded style rocker with 9 bolt
    old.png


    New assembly - boat style rocker with 5 bolt new.png
     
  2. jeff campbell

    jeff campbell Lives in an IH Dealership

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    I dont see why it wouldn't work !
     
  3. winchested

    winchested Y-Block King

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    Just use thread sealer on them.
     
  4. Ron A

    Ron A High Wheeler

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  5. jordandoc

    jordandoc Binder Driver

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    The reason they are worn (according to your picture) is the the oil holes were on top. Someone must have used the "boat" rockers on the welded rocker shaft. The "boat style" rockers used the same shaft except turned upside down so the oil holes were on the bottom. The welded rockers used the oil holes on top. I prefer the "boat style" stamped rockers but a lot of times I'll use shafts from the welded rockers but turn them upside down. It's like having a new shaft!
     
  6. trobbl

    trobbl Farmall Cub

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    Good theory. Who knows what combinations may have been used on an engine this old. My theory is oil starvation. There was a lot of sludge inside the rocker shafts and the oil galley in the shaft stand on the worst side was completely plugged up. My theory is oil starvation.

    Rest assured, after cleaning up the replacement rocker assemblies, I made sure the oil holes are one the bottom since I'm using boat style rockers now.
     
  7. Mark Pietz

    Mark Pietz High Wheeler

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    I'm running that a shaft that was turned over just for that purpose. Plus, I added the "missing" stands to make it a 9-stand setup, and ditched the springs. Overkill, probably.
     
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  8. trobbl

    trobbl Farmall Cub

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    That gives me food for thought. I have all the spare parts from the old rockers, so I could go to 9 stand without any trouble.
     
  9. kevingweq

    kevingweq Y-Block King

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    Just to keep the info in one thread ,There is an outfit that rebuilds shafts and rockers , Rocker Arms Unlimited
    I sent them these shafts ...
    20150617_212855 (1024x768).jpg


    And got these back , Built up and reground

    rocker shafts 345.jpg
     
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  10. winchested

    winchested Y-Block King

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    Dude that's awesome! What kinda dough dit it run. I wonder if they'd do my worn ol boat style rockers. And shafts. If I ever run a better cam and get some new lifters this would be worth doing.

    Details? On how much it cost you?
     
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  11. Bill Bennett

    Bill Bennett High Wheeler

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    So, if the company can rebuild the rockers, what if the center bushing could be moved just enough to shorten the distance from the lifter rod to the new center of the rocker shaft. That would increase the rocker ratio and provide a higher lift at the valves? Didn't IH have some engines with 1.6 rocker ratio and some engines with 1.7 rocker ratio? (asking for a friend.)
     
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  12. kevingweq

    kevingweq Y-Block King

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    I don't know what they could do with boat rockers , as they have no replaceable bushing??
    The shafts built up and ground back to stock size ( Quoting from memory, I will try to find the slip) was $100-140) thereabouts
    Just to clarify the rockers in my picture are NOS .
    Normally they will grind and build the shafts and then use undersize bushings in the rockers , I did not price the rebuilt rockers .
    (Bill ) If the bushings would take an offset bore without any other clearance issues ?? I would think these folks could do it .
    Maybe roller rockers would be a better option at that level of modifications ??
    The company was great to deal with and IMO did a fantastic job on the shafts ( installed the proper oil cup plugs also )
    For more info I would call them , When I spoke to them ,the fella who actually owned the place answered my questions
    Good Luck
     
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