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  •  » Rocker arm problems

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    2/26/2021 12:05 AM  #1

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    Rocker arm problems

    OK got my new 289 built and was installing the stock rockers and discovered that the sides hang down and hit the top valve retainer before the the valve stem. Not good. 

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     

    2/26/2021 6:21 AM  #2

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,499

    Re: Rocker arm problems

    Hmn, I'm assuming the heads were rebuilt?

     

    2/26/2021 9:42 AM  #3

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,853

    Re: Rocker arm problems

    "Pictures-worth-a-1000-words".........
    Do you have studs or is it pedestal mount?
    What has changed (so much) from the original "pre-rebuild engine"?
    Were the heads milled?...Was the block decked?
    Roller rockers may "fix-it" butt......... why the big change is the question.
    6sal6

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    2/26/2021 10:04 AM  #4

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,499

    Re: Rocker arm problems

    It initially sounds like the pushrods are too short.  The pushrod should set the height of the bottom of the rocker.  Are these the original pushrods?  Have you changed the style of lifter (gone from roller to flat tappet for example)? 

     

    2/26/2021 11:15 AM  #5

    Raymond_B
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    From: Fort Worth, TX
    Registered: 4/01/2013
    Posts: 1,205

    Re: Rocker arm problems

    I think 6S6 is on to it. Didn't of the late 60's-80's model SBF come with pedestal rockers and have caps on the end of the valves that required that type of rocker? Are these the same rockers that came with the 289 or have they been sourced elsewhere? Pretty sure you're going to need new rockers.

     

    2/26/2021 11:30 AM  #6

    Greg B
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    Registered: 4/01/2013
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    Re: Rocker arm problems

    You have the wrong valves, or the wrong rockers.  The solution is going to be to change the valves, or change the rocker arms....And add guide plates.

    Last edited by Greg B (2/26/2021 11:31 AM)

    If multiple things can go wrong, the one that will go wrong will be the one that causes the most damage.
     

    2/26/2021 11:47 AM  #7

    Greg B
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    Re: Rocker arm problems

    http://www.pbm-erson.com/content/erson_fordtech

    If multiple things can go wrong, the one that will go wrong will be the one that causes the most damage.
     

    2/26/2021 1:02 PM  #8

    red351
    I FYI 24-7

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    From: Carlisle, PA
    Registered: 5/31/2018
    Posts: 445

    Re: Rocker arm problems

    Cab4word67 wrote:

    OK got my new 289 built and was installing the stock rockers and discovered that the sides hang down and hit the top valve retainer before the the valve stem. Not good. 

    So are you saying the 2 outside guild rail are in contact first. Some heads had no pushrod guides, so the 2 rails keep the rockers centered on the valve tips.
    Wrong valves or wrong rockers?

     

    2/26/2021 1:19 PM  #9

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
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    Re: Rocker arm problems

    Valves are wrong heads have been returned for correct valves all other parts were correct

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
       •Thread Starter
     

    2/26/2021 2:26 PM  #10

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    Re: Rocker arm problems

    Greg B nailed it. Shop found the box had wrong valves in it. Miss labeled.

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
       •Thread Starter
     

    2/26/2021 5:16 PM  #11

    MS
    Forum Originator

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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,260

    Re: Rocker arm problems

    You have installed rail type rocker arms on non-rail type valves.

    OPTION 1
    Change the rocker arms to non-rail type used with hardened pushrods, screw-in studs and guide plates.  Be sure to use correct length pushrods for this combination.

    OPTION 2
    Change the valves to rail type having longer stems.  Be sure to use correct length pushrods for this combination.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    2/26/2021 5:29 PM  #12

    red351
    I FYI 24-7

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    From: Carlisle, PA
    Registered: 5/31/2018
    Posts: 445

    Re: Rocker arm problems

    I have 1 set early 289 heads (rail style) in the archives that have valve tip caps for clearance.   Factory?   I don't know.

     

    2/26/2021 5:39 PM  #13

    MS
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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,260

    Re: Rocker arm problems

    Factory exhaust valves on the longer valves did have lash caps.  Cannot remember if ever saw them on intakes.

    Also, some early heads using non-rail type rockers did have self-guiding holes in the heads where the pushrods came through. That type head should NOT be used with guide plates.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    2/26/2021 5:46 PM  #14

    MS
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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,260

    Re: Rocker arm problems

    Had you fired that engine, it would have immediately released every valve keeper, dropping the valves into the cylinders and destroying the entire engine block.  Good thing you noticed!

    Apologies to Greg B.  I did not see his reply before posting mine, stating exactly the same thing!   Great minds think alike...

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    2/26/2021 7:30 PM  #15

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    Re: Rocker arm problems

    MS wrote:

    You have installed rail type rocker arms on non-rail type valves.

    OPTION 1
    Change the rocker arms to non-rail type used with hardened pushrods, screw-in studs and guide plates. Be sure to use correct length pushrods for this combination.

    OPTION 2
    Change the valves to rail type having longer stems. Be sure to use correct length pushrods for this combination.

    MS, these are all stock parts from my motor, just had wrong valves installed by the shop, he says the box had the wrong valves in it.
    Thank god I never turned the key for the 20 minute cam brake in
     

    Last edited by Cab4word67 (2/26/2021 8:00 PM)

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
       •Thread Starter
     

     

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