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Hot Rods Another 392 Hemi Question?

Discussion in 'The Hokey Ass Message Board' started by moparjack44, Nov 29, 2023.

  1. moparjack44
    Joined: Nov 8, 2005
    Posts: 659

    moparjack44
    Member

    Pulled my plugs yesterday, oil on the plugs and contacts on all plugs, and the poreclain black. Oil pressure good, 50 at 60 MPH, 40 at idle, 60 at first start up. Oil level good, no smoke. Ant ideas? Appreciate any suggestions why, and solution.
    Thanks,
    Jack
     
  2. Multiple thoughts. 1st: did oil run into the cylinders when you removed the plugs? There's a reason that racers mounted the oring seals in the plug areas on the heads. 2nd: use a leakdown meter and see how it tests. If you have sealing problems, the leakdown will tell you where to look. 3rd: is this a fresh ring job or something else? More info required. :)
     
    Desoto291Hemi likes this.
  3. Oil pressure has little to do with actually burning oil. Do more research.
     
    Desoto291Hemi likes this.
  4. bchctybob
    Joined: Sep 18, 2011
    Posts: 5,768

    bchctybob
    Member

    It’s common for there to be fresh oil on the threads and the tip of the spark plugs when you remove them from a Hemi with stock spark plug tubes.
    While running, oil can run down and collect along the outside of the tubes. When you unscrew the spark plugs the tubes can rise slightly allowing the collected oil to get onto the threads and tip of the plugs and into the cylinders. It’s not an indication of anything, just a design quirk.
    As mentioned, they do (did?) make seal kits for the outside of the spark plug tubes but they are mostly used in racing applications.
    If there is oil on the porcelain body of the plugs above the sealing surfaces, that is strange. Maybe oil vapor condensing under the spark plug wire covers? I would inspect the tubes themselves looking for holes possibly caused by corrosion. They are made from thin aluminum. If the core engine sat outside for years, water could have accumulated in the tubes and created pinholes that went unnoticed. I’ve seen a few in unprotected junkyard engines.
     
    Pist-n-Broke likes this.
  5. bchctybob
    Joined: Sep 18, 2011
    Posts: 5,768

    bchctybob
    Member

    Photos of the engine and spark plugs would be nice.
     
  6. jaracer
    Joined: Oct 4, 2008
    Posts: 2,929

    jaracer
    ALLIANCE MEMBER

    I don't know how many times I looked at cars using oil and the customer said there is no smoke. The way I tested for oil getting into the combustion chamber was to run the engine for 2 or 3 minutes or so at around a steady 1800 - 2000 rpm (fully warmed engine). Then let off the throttle then snap the throttle a couple of times. If it is using oil you will see smoke sometimes quite a bit.

    I learned this when I was service manager at a Dodge dealership. If you ever overheated a Dodge Omni, the rings would lose tension and the engine would start using oil. Well it was burning the oil it didn't obviously smoke. The above test worked every time.
     
    ChevJerico likes this.
  7. moparjack44
    Joined: Nov 8, 2005
    Posts: 659

    moparjack44
    Member

    1st. Yes 3rd. No, close to 100000 miles.
    Talked to Eric at Hemi Hot Heads, he advised common the tube (head end) gets out of shape over time. He advise be sure to have it flat, by using a hammer and piece of wood, and flat surface to lightly tap top of the tube against a the flat surface. Going to give that a try when I receive my new wires and plugs.
     
  8. moparjack44
    Joined: Nov 8, 2005
    Posts: 659

    moparjack44
    Member

    Cleaned plugs and reinstalled, until I get my new plugs and wires.
     
  9. dart4forte
    Joined: Jun 10, 2009
    Posts: 730

    dart4forte
    Member
    from Mesa, AZ

    Are you using the seal rings on the plugs? Suppose to run the plugs without those rings. The bottom of the tube acts as the gasket. If you are the plug seal rings are distorting the bottom of the tube allowing oil to seep through
     
    73RR likes this.

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