T/A roller rocker installation question

Discussion in ''Da Nailhead' started by 66 buick guy, Sep 24, 2017.

  1. 66 buick guy

    66 buick guy Member

    Hey everyone. I'm just curious if anyone on here using TA roller rockers and their 1423 shorter push rods has had an issue with not being able to get to zero lifter preload on the flat side of the cam.....Problem is; the roller rockers only have about 3 turns of push rod adjustment in and out....All the way out on the adjusters I'm still at roughly 300 thousands lifter preload.

    Thanks
    Mike
     
  2. telriv

    telriv Founders Club Member

    What engine????
     
  3. 66 buick guy

    66 buick guy Member

    Tom, it's a nailhead....NH 600 Poston cam, 1423 TA pushrods, TA rollers, and I had Bob install the chevy valves and beehive springs....

    Thanks Tom

    Mike
     
  4. 66 buick guy

    66 buick guy Member

    Bob said 4 thousands milled off the heads as well...
     
  5. LARRY70GS

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

    Push rods are the wrong length. If you look at the TA Roller rocker instruction sheet, it tells you that when you have adjusted the rocker arm, the adjuster should be flush with the bottom of the rocker. One thread showing, or one thread recessed is acceptable. Any more than that and you need either longer or shorter push rods. Get one adjustable push rod, measure a few valves with the adjuster flush, and order the right push rods.

    http://www.taperformance.com/PDF/Roller_Rockers_Installation.pdf
     
  6. gsgtx

    gsgtx Silver Level contributor

    the nail head roller rockers are different then the 350-455. you can not even go recessed
     
  7. LARRY70GS

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

    OK, but if you don’t have an adjustment range at the rocker arm, the push rod length has to be wrong. Does TA even make roller rockers for the Nailhead or are these Tom Telesco’s?
     
  8. gsgtx

    gsgtx Silver Level contributor

    Larry, they are ta rockers.
     
  9. LARRY70GS

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

    I’m not familiar with the Nailheads, but if you cannot adjust the rocker, then the push rod length must be wrong, no?
     
  10. telriv

    telriv Founders Club Member

    As stated use an adjustable pushrod to check the proper length, of not just one, but ALL the lifter pre-loads. Then add ALL 16 up & divide by 16 to get the correct length. IT DOES MAKE A DIFF. IF the pushrod has 5/16ths. ends or 3/8ths. ends. So use the appropriate pushrod end. You can use a 5/16ths. pushrod end in a 3/8ths. lifter cup BUT not the other way around. I don't know if T/A's rockers can use either end or not.
     
  11. roadrunnernz

    roadrunnernz Gold Level Contributor

    I notice the 1423 pushrods are listed for the 455, 1428 for the 401.
     
  12. TA Perf

    TA Perf Member

    Mike,
    The problem I believe is the fact you had Bob install Chevy valves, now the valve tip height is way off, to high. This will rotate the rocker and push the plunger down. Installing a shorter pushrod will probably not fix it because the rotation of the rocker will also move the pushrod to touch the upper side of the pushrod passage way in the head, putting into a bind. You need to get the tip height back as close to Buick spec's as possible. I believe the tip height should be 1.540" from the gasket surface to the tip of the valve. If you want to use Chevy valves, figure out how much shorter they need to be and have a set made.
     
    322bnh likes this.
  13. 8ad-f85

    8ad-f85 Well-Known Member

    I can think of a few ways I've solved this with Chevy valves.
    I think the best thing to do is contact Bob to have him refresh his intentions as he's done this before, and double check the part number of your pushrods...as suggested already.
    Not throwing stones, but I'd hope the order taker would catch the mismatch before shipping.
    A simple "is this for the same engine?" could have helped if that was the case.
     
  14. 66 buick guy

    66 buick guy Member

    Pushrods are 1423-8300a which does get me fairly close to where I need to be (they are roughly 7/16 of an inch shorter than the stockers)...with 70 thousands thick washers temporarily under the rocker shaft mounts I have plenty of valve lash on cylinder 1 exhaust valve but still roughly 2-5 thousands preload on cylinder 1 intake valve...at zero lash the exhaust pushrod isn't touching the casting hole (very close) but the intake pushrod is touching the casting. ...I talked to Joe about carefully removing the burrs in the hole castings to help with that....I'm hoping if I go with Carmens 8.2 pushrods I will have just enough clearance with 22 thousands head gaskets..... all of these measurements have been without the head gasket installed...

    Thanks guys

    Mike
     
  15. gsgtx

    gsgtx Silver Level contributor

    i have use custom valves and chevy valves both have worked with TA rockers. the TA push rods they sent are about the same length am using. thinking you need a shorter push rod could be the lifter your using the hi rev lifter from poston. either the lifter is deeper or the cup is smaller and the push rod is not seating all the way in the cup. your block was not decked and if your heads were not milled that much, what else could it be ? base of cam lobe ? wouldn't think it would be that much ?
     
  16. dual-quadism

    dual-quadism Black on Black

    I am doing some upgrading on pushrods on several other motors I am building now including a GN 3.8 turbo and several SBC's and LS's. The more I learn about pushrods, the more I realize how you really cannot have a stiff enough one. I think this is especially true with Nailheads do to the inherently bad valvetrain geometry. We don't rpm these motors much, but general pushrod length is 8.700ish which is "long" in general compared to other performance built v8's. Pushrod deflection is a big deal as rpm climbs and load builds. Dont even waste your time with adj pushrods, just Get a comp PR length checker kit and figure out what the motor wants. Of all the nailheads I have built, most have individual lengths mostly do to block/head surfacing and aftermarket gaskets. Basically, each build is unique. I am working on some pushrod/cam kits to come to market maybe early next year. I am tired of the rehashed same 40+ year old tech applied to these and other vintage v8's and am deciding to do something about it.
     
  17. 66 buick guy

    66 buick guy Member

    Im going to send the valves to Tom and have him machine roughly .080 off of them....It's my only option because the ferrea valves are still at 4.910 original height; that tall of a valve height is peaking out the upward travel on a few of my rocker arms..... as of right now my install valve stem height is 1.7 give or take .020...I will also need to get different keepers....I'm guessing I'll be using something close to an 8.4 ish pushrod length in 5/16 diameter. ....Does anyone know the part number for the comp cams lowest possible beehive keeper I can get?

    Thanks guys

    Mike
     
  18. gsgtx

    gsgtx Silver Level contributor

    you need to know first if you have 7* retainers or 10* retainers
     
  19. 8ad-f85

    8ad-f85 Well-Known Member

    Make sure you aren't grinding past any hardening or tip insert if you were intending it for your build strategy.
    That's one of those things preferably already worked out during head work.
    It's easy to hide some stem length when you are slightly enlarging the valve diameter.

    I'd probably set those valves aside and either order more shipped directly to a local shop that grinds in house or purchase different valves altogether... rather than ship valves two ways with more labor added to them.
    Just put your chevy valves back into the next chevy.
    Another way I've shortened stem protrusion is to grind the OD smaller, making the margin thicker and pulling the valve stem in.
    The valve's OAL is the same but it puts more of it into the chamber than leaving stem protrusion.

    Simple shims mocked up didn't solve your problem?
     
  20. 8ad-f85

    8ad-f85 Well-Known Member

    Cutting the valve seats shallower, leaving less of the top cut (above the sealing angle) pulls the stems down some.
    The typical 30* top cut usually worsens flow anyways. It's better to have barely any of it showing for a few reasons.
    That along with a thicker margin valve can lose .080" easily.
     

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