Oil Pressure

Discussion in 'Technical' started by BIG T, Jun 14, 2015.

  1. BIG T

    BIG T Member

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    Hello, here is what I have.
    1. 5.0 Short Block used.
    2. New Main and Rod bearing
    3. New Melling 5.0 oil pump standard volume.
    4. before start, I primed the oil pump, gauge showed 60 lbs.
    5. Car starded right up, no oil pressure shut it down
    6. re-primed oil pump gauge showed 40 lbs
    7. Re-stared , gauge showed 20 PSI at idle, ran 10 minute Oil pressure went to zero.
    8. Tried to re-primed, still no oil pressure I'm using a boss 302 oil pan and pick up. (I did fill with 6 QT) I order the oil pump for a 5.0. I did find the oil pump will not turn clockwise by hand using the ARP primer rod. It will turn by hand counterclockwise. I did prime by spining the drill counterclockwise. I also change the oil pressure gaug, It still show zero.
    Any help would be welcome.

    Thanks
    Tony
     
    BIG T, Jun 14, 2015
    #1
  2. Mavman72

    Mavman72 Gone backwards but lookin' forward

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    Is your oil pump drive shaft engageing the distributor??? Oil galley plug fell out or missing/leaking oil past one of em. Gonna have to pull the timing cover to see. Bypass valve in pump stuck open... These are tho common reasons other than excessive bearing clearances...Good luck!!!
    OOPs...Almost forgot the Plugged oil filter...Seen it man...It happens.
     
    Mavman72, Jun 14, 2015
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  3. Krazy Comet

    Krazy Comet Tom

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    Well a pump that won't spin in both directions has a problem, whether that is your issue I dunno... Have heard mentioned that Melling pumps aren't what they used to be, often had burs of metal inside left over from machining...
     
    Krazy Comet, Jun 14, 2015
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  4. BIG T

    BIG T Member

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    UP-DATE 06/15/2015. I pulled the oil fliter, it was full. With the oil filter off, I barely hit the drill with the primer rod attach and oil came flying out.:clap: That should mean the oil pump ,pick-up tube is good. Going to change the oil fliter and hope for the best. Thanks for the replies.
    Thanks
    Tony
     
    Last edited: Jun 15, 2015
    BIG T, Jun 15, 2015
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  5. BIG T

    BIG T Member

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    Up-date 06-15-2015 Tonight. I pulled the front timing chain cover and timing chain and gears. When I hit the drill I could see the #1 main getting oil, The cam thrust plate was oilimg. When I pulled the cam thrust plate and hit the drill my gauge shows 40 psi. What up with that?
    Later
    Tony
     
    BIG T, Jun 15, 2015
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  6. Krazy Comet

    Krazy Comet Tom

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    Well if temp was around 45 - 50* I'd say normal, as all oil is really too thick flow well at those temps... At '70*+ I'm guessing it would be less maybe 25psi(but really dunno)... Still at room temp oil sort of drags through the galleys which creates resistance to flow, thus you have oil pressure... At operating temp, pressure would no doubt be all but zero...

    What weight oil are you using??
     
    Krazy Comet, Jun 16, 2015
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  7. BIG T

    BIG T Member

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    Up-Date 06-16-2015. I clean up the trust plate and installed, set the bolts to 10 foot pound with thread locker (red). I have oil pressure on the gauge. The faster the drill, the more oil pressure. My set up is 6 quarts of 10/30W, NAPA GOLD filter (1515). It is about 65 deg in Ventura CA.

    Thanks
    Tony:thumbs2:
     
    BIG T, Jun 16, 2015
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