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Technical Lil' ticking after reaching operating temp

Discussion in 'The Hokey Ass Message Board' started by Hotrodjohn71, Sep 22, 2021.

  1. Hotrodjohn71
    Joined: Feb 25, 2018
    Posts: 67

    Hotrodjohn71

    Oil weight question.

    I'm in the '500 mile break-in' phase of my bone stock 1965 Pontiac 326 engine.
    Im using Driven BR30 break-in oil for the 500 mile break-in.
    I have a hydraulic flat tappet cam which I did correctly break in, drained the oil & changed filter afterwards.
    When the engine is cold, and until warmup, the engine is nice and quiet, but I've noticed that when it's hot, theres a little bit of audible ticking from the rocker arms.
    Not audible in the car, but audible in the engine compartment.
    My question is could this be caused by the 30 weight here in warm California and if so, which weight is recommended to add after 500 miles?
    Thanks
     
  2. harpo1313
    Joined: Jan 4, 2008
    Posts: 2,303

    harpo1313
    Member
    from wareham,ma

    Did you adjust the lifters by the book?
     
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  3. Hotrodjohn71
    Joined: Feb 25, 2018
    Posts: 67

    Hotrodjohn71

    On this 1965 Pontiac 326. There in no adjustment whatsoever. The nuts are not self locking. You just run all of the nuts down and torque to 20+ pounds.
     
  4. Primered Forever
    Joined: Jul 7, 2008
    Posts: 424

    Primered Forever
    Member
    from Joplin,MO

    Did you check all your of pushrods for length and the preload on each?
     
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  5. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 3,524

    2OLD2FAST
    Member
    from illinois

    Lifter pre-load is set by the machinist doing the valve job setting the installed ( stem) height correctly . unfortunately , most machinists who knew this have long since hung it up !
     
    SEAAIRE354, Deuces, fauj and 2 others like this.
  6. I have zero Pontiac experience but is it possible to swap adjustable rockers from a different year?
    For example, my 340 Duster had shaft rockers that were not adjustable but earlier 273's could be had with adjustable shaft rockers that I could have swapped on if deemed necessary.
     
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  7. Hotrodjohn71 likes this.
  8. onetrickpony
    Joined: Sep 21, 2010
    Posts: 529

    onetrickpony
    Member
    from Texas

    There are several of ways to increase the lifter preload on a Pontiac. The easy way is to add a hardened machine washer under the nut but hardened washers with both faces machined flat and parallel can be hard to find.

    The second way is to order longer push rods. They used to be available with an extra .015" length but may not be available with out custom ordering now.

    The rocker or ball could also be worn out. You may just need a new one.
     
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  9. Mr48chev
    Joined: Dec 28, 2007
    Posts: 30,040

    Mr48chev
    ALLIANCE MEMBER

    Unless the machine shop took a lot of material off the tips of the valve stems dressing them the preload should be should be more rather than less as the valves will be slightly deeper in the seats.
    The average automotive machine shop isn't going to be setting those heights on a regular valve job on a set of daily driver heads though.
     
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  10. Could it be rocker noise ,,,,,kind of like a ticking sound .
    Sometimes there will be slight noise from the rocker face and valve tips not being perfectly new and smooth .
    Just an idea .

    Tommy
     
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  11. MAD MIKE
    Joined: Aug 1, 2009
    Posts: 674

    MAD MIKE
    Member
    from 94577

    30 is good for ~95°F max ambient.
    40 is good for ~105°F max ambient.
    50 is good for ~120°F max ambient.
    I run 40 weight in just about everything unless it is the cooler months and then I'll switch to 30 weight.

    50 is too thick for anything outside of Arizona heat or race events.

    Ideally you would have an oil temp sensor and see what that shows. Use an oil appropriate for those temps.
     
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  12. Can also use poly locks instead of the stock rocker nuts.
     
  13. ottoman
    Joined: May 4, 2008
    Posts: 318

    ottoman
    Member
    from Wisconsin

    No not with the the style rocker stud he has. You just tighten the rocker nut untill it hits the stop on the stud. I have put shims above the pivot ball or longer push rods if needed
     
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  14. Hotrodjohn71
    Joined: Feb 25, 2018
    Posts: 67

    Hotrodjohn71

    I had assumed that there *wasn't enough lifter preload, hence the ticking, but it appears my assumption might be 180° off.
    I checked the preload and it appears that with my studs (which dont have adjustable nuts - just torque to 20#) that each nut seems to turn about 1 3/4 turns after zero lash.
    I've read that a half turn should be enough.
    Could this be the reason for the ticking?
     
  15. Deuces
    Joined: Nov 3, 2009
    Posts: 21,294

    Deuces
    Member
    from Michigan

  16. krylon32
    Joined: Jan 29, 2006
    Posts: 7,503

    krylon32
    Alliance Vendor
    from Nebraska

    This may sound stupid but I have encountered the same thing on my 40 coupe with a small block Chevy. I listened and listened and when cold the engine was quiet and as it reached operating temperature at highway speeds it began to tick. After much frustration with the noise I finally chased it down to a slight exhaust leak when the engine was at operating temp. Got out a wrench and went over the exhaust manifold and header connection and the tick seems to have went away.
     
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  17. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 2,465

    Elcohaulic
    Member

    I've owned well over 15 Pontiacs in my day. 389s, 421s, 455s, 400s.. Every one with a hyd. cam ticked or chattered. The ones with the solid lifter cams ticked but it was in time with the engine speed, the hyd tick is kind of all over the place.. Frankly I don't know why more people dont run solids in Pontiacs.. They really do run better..
     
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