401 rebuild with tapping noise...

Discussion in ''Da Nailhead' started by 1966buickgs, Aug 22, 2016.

  1. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

  2. John Codman

    John Codman Platinum Level Contributor

    If all 16 lifters aren't identical, and the engine builder supplied them, it should be his problem and not yours.
     
  3. doc

    doc Well-Known Member

    OK.... both Tom and Larry are right,,, the diagram that Larry sent shows you how the system works.... if the bolts at those front locations are not the ''waist '' type ,,,, check all your bolts holding the rocker arm assemblys to the heads... the builder most likely just installed them in the wrong location,,, if you dont find them then you can take the bolts that are in there and ''machine'' them with your bench grinder or a large flat file just above the threads up to a quarter inch below the head..... :Smarty: just grind flats about 1/4 in wide,,, no more,,,, and then tighten the bolts down to 35# with a torque wrench , no more.... and then you should get plenty of oil to the rocker arm shafts....
    Like said,,, you need to get your self a good shop manual.... either factory ones or the old motors manual.... shop manuals dont cost,,, they pay off,,,, big time... you can save a ton of money by using them to do things your self... plus you get a bunch of self satisfaction... :Smarty: now back to the oiling,,, the rocker arm shafts are hollow all the way thru to transport pressurized oil to all the rocker arms... in the rocker arms there are small holes drilled to feed both the cup side and the rocker arm tips... on the tip side oil comes out of the hole runs down the top of the rocker arm and splashes onto the tips... on the cup side the oil comes out between the ball on the pushrods and the cup... YOU SHOULD BE GETTING OIL COMING OUT AND DRIPPING DOWN AT THE TIP SIDE AND THE CUP SIDE + AT THE JUNCTION OF THE ROCKER ARM AND SHAFT... IF NOT ,, THERE IS A PROBLEM.... the shafts, over time, will ,, will,, fill up with cold sludge and the oil cannot get thru,, this is why it is important to clean inside the shafts at rebuilding time.... with a rifle cleaning rod and brush....and solvent,,, then follow with compressed air,, also break down the whole assembly to clean inside the rocker arm oil holes with a small drill or wire....
    If you submerge the parts in simple green cleaner ,, the pure stuff,, and let them soak overnight ,,, they will come clean as new,,, just rinse them in water and blow out with compressed air....
    you will ruin the end plugs taking them out , because you have to drill a small hole in them and run a sheet metal screw in there to pull them... dorman sells replacements,,, take the old ones to the store to match up... if worse comes to worse , you can solder the holes you drilled out and then swage the old ones back out to size and re use them... maby this will help.... :TU:
     
  4. wkillgs

    wkillgs Gold Level Contributor

    These are the correct bolts:
    DSCF1513 (Copy).jpg
     
  5. GSBuick65

    GSBuick65 Well-Known Member

    What lifters did you use?


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  6. Aussie V8

    Aussie V8 Well-Known Member

    On my rebuilder engine some of these bolts are missing. Do only the front 2 shaft housings need these bolts, or all 8 ?
     
  7. wkillgs

    wkillgs Gold Level Contributor

    Just the front bolt on each side..... that's where the oil comes up from the head. Oil flows along the skinny portion of the bolt shank and into the rocker shaft.
     
  8. Aussie V8

    Aussie V8 Well-Known Member

    Thanks Walt. :TU:
     
  9. bullheimer

    bullheimer Well-Known Member

    so one better not pull the bolts out without marking them or your going to get no oil to the rockers? oiee!
     
  10. doc

    doc Well-Known Member

    The most common thing to restrict rocker arm oil is sludge that collects inside the rocker arm shafts over the years.... they need to be scrubbed out with simple green and a rifle brush at each rebuild and then blown out good with compressed air....:Smarty:
     
  11. 1966buickgs

    1966buickgs 1966buickgs

    I went with Delphi lifters from Russ Martin this time. They are made here in the U.S.A. by the uaw.I bought the rebuild kit from old parts source and the lifters that were in that kit failed,at least 2 that I found. I think they were called rebuilders choice. Any how,thank you all for the help an so far so good with Brad Pen break in oil and DelphI lifters. Oh an I've had that dictionary of a chasis model the whole time an some information is better explained from someone who has experience working on these motors an the problems I've had. I would rather ask an get clarification than read the chassis model not quite understand something an end up making a costly mistake. An let's face it there is no room for mistakes on these antique motors! Thanks again!
     
  12. GSBuick65

    GSBuick65 Well-Known Member

    Good deal, maybe I need to try Russ' lifters

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