Sheared Distributor Roll Pin

Discussion in 'Street/strip 400/430/455' started by Brett Slater, Apr 18, 2022.

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  1. Brett Slater

    Brett Slater Super Moderator Staff Member

    Well....went to take the car for an inspection sticker and maybe do a few things to it on my day off.

    Got in, started right up, idled for an bit then died. I had a sneaking suspicion and pulled the distributor to find the gear still sitting on top of the oil pump shaft.

    This is the second one I've sheared a roll pin within a couple hundred miles or so and I'm beginning to get annoyed.

    Motor is new with about 2K miles on it. I'm using Valvoline VR1 10-30 and the big money TA cover that I ran on my old motor.

    What say yee?
     
    Brett Slater, Apr 18, 2022
    #1
  2. Bigpig455

    Bigpig455 Fastest of the slow....

    Something is clearly binding. What's your oil pump end play? When the first one went did you see any scoring in the pump assembly?
     
    Bigpig455, Apr 18, 2022
    #2
    Mark Demko likes this.
  3. BQUICK

    BQUICK Gold Level Contributor

    How much oil pressure on cold start-up?
     
    BQUICK, Apr 18, 2022
    #3
  4. Brett Slater

    Brett Slater Super Moderator Staff Member

    I didn't.

    I'm
    I didn't. I'll check when I get back to the car and am unaware of the end play. All I know is the TA cover was left as it was when they sent it to me.
     
    Brett Slater, Apr 18, 2022
    #4
  5. Brett Slater

    Brett Slater Super Moderator Staff Member

    Using the grid Scott Moody sent back with my recalibrated factory gauge, the needle is a hair above the "H" which calibrates to right above 60 lbs.
     
    Brett Slater, Apr 18, 2022
    #5
  6. BQUICK

    BQUICK Gold Level Contributor

    That should be fine. I've seen them shear at 90+ or if relief valve is stuck.
     
    BQUICK, Apr 18, 2022
    #6
  7. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Where are you sourcing the pin?

    Is it a clean shear or is the pin loose and working its way out first?
     
    436'd Skylark, Apr 18, 2022
    #7
    Schurkey likes this.
  8. Brett Slater

    Brett Slater Super Moderator Staff Member

    I had a box of them I've had for a while. Are there different ranges of quality roll pins?

    Sheared clean off.
     
    Brett Slater, Apr 18, 2022
    #8
  9. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    I would assume they come in all sorts of different grades. There must be a difference between the distributor roll pin and a pin that simply holds a cabinet handle in place... the cheaper ones probably are not hardened..
     
    436'd Skylark, Apr 18, 2022
    #9
    Brett Slater likes this.
  10. Stage 2 iron

    Stage 2 iron Platinum Level Contributor

    Brett, contact TA performance I believe they sell heavy duty pins.
     
    Stage 2 iron, Apr 18, 2022
    #10
    Brett Slater likes this.
  11. LARRY70GS

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

    With a 60 lb. sender, a bit above H could be anything over 60. For all you know, it is 90. If you have an adjustable regulator, back it out.
     
    LARRY70GS, Apr 18, 2022
    #11
  12. CJay

    CJay Supercar owner Staff Member

    I dont think a hair above H translates to excessive pressure
     
    CJay, Apr 18, 2022
    #12
    dentboy and Brett Slater like this.
  13. john.schaefer77

    john.schaefer77 Well-Known Member

    I sheared 2 myself. Then I stopped using the cheap harbor freight ones i had in my garage and used some old American made ones I found a Ma & Pop hardware store. Been on for 9 years now.
     
    john.schaefer77, Apr 18, 2022
    #13
    Mark Demko, Max Damage, Dano and 1 other person like this.
  14. LARRY70GS

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

    My point is a 60 lb. sender pegs the gauge at 60 psi. It can't go any higher. So 70, 80, 90 psi will produce the same reading.
     
    LARRY70GS, Apr 18, 2022
    #14
  15. 12lives

    12lives Control the controllable, let the rest go

    Larry - At what pressure would you expect the pin to shear?
    Brett - Might be a good idea to put a gauge in the sender hole and see what you actually get on cold startup.
     
    12lives, Apr 18, 2022
    #15
    Brett Slater likes this.
  16. LARRY70GS

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

    Depends on oil temperature, RPM, and pressure. If you rev the engine to 4000 at 60 psi, it might shear it with cold thick oil, or it could do that at half the RPM at 90-100 psi. I think it is a good idea to see what the actual pressure is. For all we know, it's at least 60 psi, maybe more, maybe a lot more.
     
    LARRY70GS, Apr 18, 2022
    #16
  17. standup 69

    standup 69 standup69

    Had one shear off my Mallory comp 9000 years ago at a cold Friday night race ..oil got a bit cold between rounds ,sheared off at 60ft ..fixed it at the track then at home drilled the gear and distributor larger for a bigger pin .that was about 17 years ago still working
     
    standup 69, Apr 18, 2022
    #17
    Brett Slater likes this.
  18. Brett Slater

    Brett Slater Super Moderator Staff Member

    I have some gauges I'll be installing when I have time dedicated to tinkering again.
     
    Brett Slater, Apr 18, 2022
    #18
  19. Brett Slater

    Brett Slater Super Moderator Staff Member

    What's the tee look like to run both the factory oil sender and aftermarket gauge?
     
    Brett Slater, Apr 18, 2022
    #19
  20. Brett Slater

    Brett Slater Super Moderator Staff Member

    This is the sheet Scott sent back with my gauge and this sending unit.

    20220418_201933.jpg
     
    Brett Slater, Apr 18, 2022
    #20
    Max Damage likes this.
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