BBB oil pressure dropping

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

  1. standup 69

    standup 69 standup69

    I also forgot to mention when did the TA cam bearings go in ? Before or after machining ?

    Yes nothing wrong with those clearances for what your doing with it ...I ran those in my last few engines ..stock pump ran it to 7000 plus bearing look great..
     

    Attached Files:

  2. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Cam bearings went in after final cleaning and all machine work was done
     
  3. 71bskylarkk

    71bskylarkk Vroom Vroom.



    Here is a video of that happened.
     
  4. standup 69

    standup 69 standup69

    Looks like your narrowing it down ...any pics of the lifter valley fill
     
  5. Stage 2 iron

    Stage 2 iron 472 IRON HEAD STAGE 2

    That start up is that cold or hot.
     
  6. 71bskylarkk

    71bskylarkk Vroom Vroom.

    Engine coolant Temps were 180-190
     
  7. 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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  8. 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
  9. Stage 2 iron

    Stage 2 iron 472 IRON HEAD STAGE 2

    Looks like the pressure definitely hesitated when you first started it up I had an issue in my stage one back in the late 80s it broke one of the gears in the oil pump the oil pressure was lazy and eventually had no more than 30 pounds of pressure it ended up taking out the crank.
     
  10. 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.
     
  11. standup 69

    standup 69 standup69

    I personally would double the amount of drain holes ...
     
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  12. 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
     
  13. 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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  14. 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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  15. LARRY70GS

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

  16. 71bskylarkk

    71bskylarkk Vroom Vroom.

    No sir. Screwed directly on the pump housing
     
  17. 71bskylarkk

    71bskylarkk Vroom Vroom.

  18. 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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  19. Jim Weise

    Jim Weise 1000+HP

    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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  20. 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.
     

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