BB burns oil. Ideas?

Discussion in 'Engine Topic' started by Hoslapper, Mar 22, 2019.

  1. G72Zed

    G72Zed Veteran Member

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    A leakdown may be a better test in this case. I've seen the wrong oil rings packaged, as in original size in a "30 over" packaged set. 2nd ring (s) installed wrong. Using syn oil and going to "easy" on the initial break in and glazing over the cylinders, bad hone prep, untrue bore finish, loose guide clearances, bad valve stem seals, Ring design and materials not matching bore finish.

    You may just have to put on more miles to see.
     
  2. Hoslapper

    Hoslapper Veteran Member

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    It seems not sure tho, that it’s only while I’m under heavy acceleration when I see smoke. Is there a good way to try to get the rings to seat if this is the issue? I really lean towards the rings due to the breather grommet was closed of during all of my break in period and probably building a lot of pressure in the crank case?
     
  3. G72Zed

    G72Zed Veteran Member

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    That’s why I suggested the leak down, If it comes in high % and points to the rings/bores not sealing up, driving it under load with extended deceleration periods may in fact do nothing. Also, perhaps there is an intake leak from the bottom in the lifter valley that leads to this oil burning under load.
     
  4. G72Zed

    G72Zed Veteran Member

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    What type of rings? Would they happen to be TS gapless tops?
     
  5. bfmgoalie

    bfmgoalie Veteran Member

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    Exactly what I am thinking.
     
  6. bfmgoalie

    bfmgoalie Veteran Member

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    In a couple engines I've had over the years (damn I feel old) when I had smoke during idling, accelerating or decelerating, it was the valve seals.
     
  7. 1980RS

    1980RS Veteran Member

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    I had a SB Vortec 350 that smoked after a rebuild. Did a bunch of stuff and nothing changed. When I changed from headers to manifolds I saw the exhaust ports on the RH side were oily. Things got worse that when I pulled the intake changed gaskets sill smoked but this time from both sides. Humm... what I found was that when I changed back to the intake manifold that I put on the car for break in the car stopped smoking period. I took a close look to fine Edelbrock machined it 2° off on the bottom like they machined it for angle milled heads. Pull your intake and see if the ports are oily right at the opening.
     
  8. Hoslapper

    Hoslapper Veteran Member

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    Ok guys thanks for the good ideas! I have some things I can try know. I hate driving around with smoke coming out of my pipes lol!
     
  9. COPO

    COPO Veteran Member Lifetime Gold Member

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    Depending on the ring material some rings take 2,000-8,000 mi to seat. If you don't have baffled valve covers or a pcv valve, then it will use oil. I would take it out and in high gear, drive at 30 mph and hammer it to 60 mph then coast back to 30 and repeat 10x's. If that doesn't seat the rings, find a steep hill and hammer it in high gear going up hill, repeat 10x's. A compression test will show good cause if oil is getting past the rings then this oil will seal the rings. If anything a leak down test will be better with WOT held open. I created a post a while back on making a leak down tester.
     
  10. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

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    1. Do a compression and a leakdown test. That will either vindicate or convict the rings as being the problem.

    2. Do a full throttle run, shut the engine off, pull the spark plugs, and read them. If any of them wet with oil or a different color other than tan/light brown, that cylinder could me the problem child.

    3. I also question the intake to cylinder head "fitment". I've seen too many rebuilt engines where the heads were milled incorrectly to reestablish the correct angle between the intake and the head(s). The hell of it is you have to pull the intake and CLOSELY inspect the gaskets for evenly sealing.

    4. I built a 302 SBC that SMOKED under acceleration! Two things caused it: too much volume = filling the valve covers at high rpm which drowned the valve stem seals which sent oil down the valve stems into the intake and exhaust ports = SMOKE! Two things fixed it: I'll gallery restictors (which are required when a solid lifter cam is installed) and a standard volume oil pump which is more than adequate for a SBC.
     

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