BBB oil pressure dropping

Discussion in 'Race 400/430/455' started by 71bskylarkk, Mar 21, 2021.

  1. standup 69

    standup 69 standup69

    Looks like your narrowing it down ...any pics of the lifter valley fill
     
  2. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Engine coolant Temps were 180-190
     
  3. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Yes I'll find some. Be warned there is a d**k drawn in my valley. Thanks to my coworkers.
     
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  4. 71bskylarkk

    71bskylarkk Vroom Vroom.

    3/8 holes until the back (behind d/s "7 lifter bore) which is 1/2"
     

    Attached Files:

    Last edited: Mar 22, 2021
  5. 71bskylarkk

    71bskylarkk Vroom Vroom.

    So my old engine with same pump n cover ALWAYS scared me. First startup, hot cold, whatever, there would be a 2-5 second delay before I saw pressure. Never did figure out why.
     
  6. standup 69

    standup 69 standup69

    I personally would double the amount of drain holes ...
     
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  7. 71bskylarkk

    71bskylarkk Vroom Vroom.

    I'm going to for sure. I know I'm not the first one to do this, so all the information helps. My boss swears it's impossible for it to be sucking the pan dry at that low rpm.

    To me, it's the only thing so far that makes sense
     
  8. standup 69

    standup 69 standup69

    I know the SBC iron eagles typically get five or more 1/2 in drainholes in a wet sump engine .that may point it in a better direction as far as return volume
     
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  9. Bens99gtp

    Bens99gtp Well-Known Member

    By chance are you using s remote mount oil filter. Something is not right for sure. I raced a junk yard 430 bottom end....never changed anything in it besides oil pan gaskets in the bottom end.....it would hold over 50 psi at idle when cold and 25psi after passes when fully warm
     
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  10. LARRY70GS

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

  11. 71bskylarkk

    71bskylarkk Vroom Vroom.

    No sir. Screwed directly on the pump housing
     
  12. 71bskylarkk

    71bskylarkk Vroom Vroom.

  13. standup 69

    standup 69 standup69

    I'm willing to bet the farm it's a drainback/ pump starvation issue everything else on the build seems within normal stuff ..the filled valley is the wildcard that keeps nagging me ...rear sump pan?.... Those first 2-3 holes slowly drain onto the shallow part of the pan then into the sump ,with static running only the back few holes were supplying the pickup ..
     
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  14. Jim Weise

    Jim Weise EFI/DIS 482

    First off.. what kind of line do you have on that oil pressure gauge?... 1/8" copper?.. if so, that's why it reads so slow. If you want go copper, 1/4 inch is minimum. A -3 or 4 AN line is your best bet here.

    I tend to agree with your boss, on not enough rpm to drain the pan of oil, and another post that mentioned possible contamination.. What your looking at in those rod bearings is foreign material going thru the journal, scratching the bearing.

    With that little run time, and never being put under load, one of two things is happening.. something is "clearancing itself" putting material in the oil, or some contamination got stuck in the oil passages somewhere, and it was there from the get go.

    Check the oil pressure regulator in the pump, to make sure the valve is not sticky or stuck open. This goes hand in hand with the material in the oil mentioned above. Does not take much to stick that valve.

    Assuming the oil temp was near the water temp, I would not expect to see more than 20psi at idle, with any stock pump, hot oil, and those clearances.

    If you find nothing else, then take the motor apart, and clean it up, and then put the mains/girdle back together and torque it up.. see if the main housings are round.

    JW
     
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  15. 71bskylarkk

    71bskylarkk Vroom Vroom.


    Thanks for chiming in JW.

    I'm running a -6 line for the crossover (too big?) I did get a chance when I pulled the cover to pull pump housing and confirmed the bypass was free and moving in and out.

    He agrees the scratching on the bearing is from a foreign object, which I can only blame myself for not cleaning it well enough, unless it's something eating itself alive.

    Tomorrow night I'm planning on tearing it the rest of the way apart if all goes accordingly.
     
  16. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Can see the line here.
     

    Attached Files:

  17. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Also I will have a oil temp gauge this next time.

    Curious if there would be any benefit to the TA pump cover, and using external pickup, also possibly a HV set up on it?

    While it's apart and down, I don't mind spending money to upgrade. But at the same time want to figure out what the issue actually was.
     
  18. Briz

    Briz Founders Club Member

    May be un related but the filled lifter galley on my last build had/has small drain back holes and that engine did much the same thing in the same way with about the same run time. The build before that had the TA lifter bore girdle and the OP was great on that one until it went over 8K
     
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  19. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Hey neighbor.

    For what it's worth, if I had to do it over again I'd run the TA girdle. Not feeling chipping out a ton of jb weld at this point
     
    Briz likes this.
  20. 482

    482 Big Member

    Any chance of to little clearance between your pick-up screen and Aluminum oil pan bottom? Thin flat Aluminum sheet being more flexable and sucking up closely to the pick-up starving the pump. You've checked the obvious, so now going to the no freakin way level.
     

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