1. 1970fury124

    1970fury124 New Member

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    Hey guys I went to install the rod bearings on my 383 and the new ones don’t have the notch for the oil on the cap. Are they the wrong bearings or is that fine?
     
  2. CBODY67

    CBODY67 Old Man with a Hat

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    As in "no groove" on one of the halves?

    IF that's what you have received, I believe that that's normal for a "normal" Chrysler B/RB block. The old Direct Connection Race Manual mentioned this, but if more oiling was desired, then the "full groove bearings" could be had for "more oil". A "hot rod upgrade", in times when more oil was deemed advisable, when possible.

    What might have been missed was the load factor on the bearings. Less bearing area means more specific loads on the remaining bearing surfaces. Plus that as the crank/bearing interface wears, a "hump" can develop on the crank itself as it wears against the bearing surface. None of this happens "overnight", but after many thousands of miles. Easier to see on a 100K engine, by observation. But the "full groove bearings" are a better way to increase oil flow through the bearing than grooving the crank journal.

    The normal Babbitt type bearing is a very "forgiving" bearing. It's softer material will allow particles to be embedded into it more than other harder-material bearings. But with a slightly shorter service life. Still with a 100K+ plus service life with decent maintenance/oil changes, even with the oils of yesteryear.

    The tri-metal bearings (under the prior name of "Clevite 77), is a harder bearing on the surface. Any particles which might have been embedded into the Babbitt would have remained "in solution" with the oil and would have scratched the crank journal as it passed through. BUT also remember that they would have had to get past the oil filter first. But their main "claim to fame" was higher load capacity, which generally meant "high performance" applications. Including what might be termed "Magnum-cammed" 383/335 and 440/375 style Mopar motors, typically. Maybe the 340s, too, but I'd have to check on that. Reason I mention "Magnum-cammed" is that the 383/330 has the normal 4bbl cam, but the 383/335 is "Magnum-cammed" (or "Road Runner/GTX cammed", as appropriate).

    Seems like the old DC Race Manual suggested buying two sets of bearings, using only the grooved halves, to make a set of full-groove bearings?

    What engine specs and what bearings did you purchase?

    Enjoy!
    CBODY67
     
  3. 66 Monaco 500 365

    66 Monaco 500 365 New Member

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    Are you talking about the little hole to feed oil to the grove through the channel in the parting line of the rod bearing to squirt oil at the cylinders?
     
  4. moper

    moper Well-Known Member

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    No reason to have the oilers anymore. They can overload the oil control rings.
     
  5. CBODY67

    CBODY67 Old Man with a Hat

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    As oil is being pumped to the bearings (rod and main), it's got to go somewhere. Like being slumg up to the camshaft and bottom side of the cyl walls, pistons, and piston pins (i.e., splash oiling).

    CBODY67