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Technical Oil inside Mallory Distributor

Discussion in 'Traditional Hot Rods' started by zz29, Oct 9, 2019.

  1. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    Long story short. Car was running OK, a bit rough at times. Put a new rebuilt distributor, car ran fine for a couple of weeks. Then starting acting up, like hesitating, jerky jerk. It got worse and worse to the point of only running for a few seconds. Specially struggling when trying to drive. Went to the fuel supply rabbit hole for a while but nothing.

    Then I decided to check out the dist. and the cap had oil in it. I don't know much but it seems to me sparks and oil don't go together. Took the Mallory out and it had oil in it, like a couple teaspoons. I put the old dist. back on, and vroom! Car runs great.

    This car seems to have constant dist. issues; why would oil find its way inside the distributor? Did I not tighten it enough? Some seal is broken? Is just messing with me because it's a hot rod and it's teaching that's the way of owning old cars?

    I'm a newbie. Car has a 49' Mercury Flathead with a SCoT blower and dual Webers 40DCOE. Mallory coil. Dist. is a mechanical advance Mallory 2-bolt crab style.
     
  2. alchemy
    Joined: Sep 27, 2002
    Posts: 14,405

    alchemy
    ALLIANCE MEMBER

    There is no real oil pressure behind the front cover where the distributor mounts, it's just the inside of the block and should be vented to the atmosphere. The distributor shouldn't really have a path for the oil to flow from back there, except around the main shaft. Maybe the shaft's bushing is worn and allowing the excess oil in? Grab the drive tang on the backside of the oily distributor and see if you can wiggle it around a bit.

    You say it's a mechanical advance distributor. Originally those crab distributors had a vacuum brake on them. The bolt with the jamb nut up top. There would be a vacuum line running from the front cover up to a vacuum source on the intake. Maybe your vacuum line is mistakenly hooked up to a place that is pressurized with oil somehow? Can we get pics of where this line goes?

    The crab distributor is held on by two simple bolts, with a thin gasket between it and the cast front cam cover. No real big torque needed to hold the distributor on. Henry Ford made special shouldered bolts to ensure perfect alignment of the distributor, but I've never had one that fit loose on the cover anyway. So if you have regular bolts those probably aren't your issue.

    Where does this engine's crankcase breathe? What vents are there on the intake? Some hot rodders used a vent on the pan too. Does yours have one? If the engine doesn't have adequate venting I'd think it could possibly be shoving oily air into your distributor. But I'd think you'd have other big leaks too, like around the front and rear seal of the crank.

    Shoot pics of all the distributor area, the intake, and the engine in general.
     
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  3. Dak Rat
    Joined: Mar 8, 2006
    Posts: 353

    Dak Rat
    Member

    I had this problem. 8BA block/oil pan. Early thickston PM-7 manifold with breather on the back like early engines use. My Mallory crab filled with oil and drown the points. Finally figured out that the early and late engines breath different and I had too much crank case pressure and it forced oil past the bushing for the distributor drive and filled the crab with oil. After much research I finally threw in the towel and removed the PM-7 and installed a late style intake with the oil fill and draft tube on the front to match the breathing system of the 8BA. It cured the problem.
     
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  4. Fordors
    Joined: Sep 22, 2016
    Posts: 2,222

    Fordors
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    Because you have a blower I will assume that your crankcase road draft tube is nonexistent, the manifold for your SCoT blower probably doesn't even have a place for it. Your engine may be building excessive crankcase pressure and oil vapors could be collecting in your distributor. You might want to give this situation some thought and decide where to locate a PCV valve and also be sure to also have a filtered fresh air supply going into the crankcase.
    This is no doubt the engine pictured in your avatar and it was built by your dad years ago, is there any chance it has excessive blow-by (bad rings) contributing to excess crankcase pressure?
     
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  5. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    IMG_9387.JPG [​IMG][​IMG] IMG_9390.JPG

    Ok; shaft on the dist that I removed is solid, no wiggle.

    This type of dist. Does not use vacuum advance. I think the Ford ones did but the Mallory didn’t?

    Not sure about what is a vent here. The blower really only has one hose (a fat one) that seems to go to the crankcase. The smaller hoses you may see, one is not connected (never has) and the other one was for a fuel regulator with vacuum but that has been capped.

    I just want to understand what might be going on and all the feedback has been great. If the work to correct/troubleshoot is major, I won’t be doing it but sending the car to my guy who knows it well. Thanks!


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  6. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    Blow-by (bad rings) as in worn cylinder rings you mean? Thanks.


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  7. Fordors
    Joined: Sep 22, 2016
    Posts: 2,222

    Fordors
    Member

    Well I will have to retract my statement, I thought your engine was the later ‘49-‘53 8BA that uses a completely different distributor and crankcase breathing system.
    You have a breather on the manifold, and the hose you mention looks to be connected to the intake manifold and the blower above the rotors. Is there a PCV valve at the manifold?
     
  8. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    [​IMG]

    Is this it? Behind blower, on the manifold between blower and engine block. You can see the hose that goes from the top of the blower to the breather tube. [​IMG]


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  9. Yep. Vent the crankcase better, then the oil vapors will stop getting pushed out of every escape route.

    WHY BE ORDINARY ?
     
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  10. Fordors
    Joined: Sep 22, 2016
    Posts: 2,222

    Fordors
    Member

    Yes, that is a PCV valve but mounted right below the fresh air supply for the crankcase it may be pulling more clean air than vapors. I think you need to relocate the valve.
     
  11. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    Ugh. Like make it taller? Hmm. Ok. Thanks for the feedback! Have to think about it.


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  12. dumprat
    Joined: Dec 27, 2006
    Posts: 2,316

    dumprat
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    from b.c.

    Move the PCV valve to the front of the engine.
     
  13. alchemy
    Joined: Sep 27, 2002
    Posts: 14,405

    alchemy
    ALLIANCE MEMBER

    OK, here's a few things:

    The cap on the back of the intake, on top of the tube, with the bullseye on it is usually a breathing cap. Probably getting a good mount of air in and out of there. But as said above, the PCV valve hooked low on that breather is probably not pulling yucky air from inside the engine. It's probably just pulling fresh stuff through that bullseye cap.

    Your distributor looks like a stock '42 Ford unit. They were made by Mallory for Ford, and came with dual points. Not sure if yours had some aftermarket alterations, only you can tell us that.

    You do not have any vacuum brake hooked up at all. I can see the small boss pointing up at 1:00 o'clock on the front cover, but no line hooked to it. The locking bolt on the plunger cylinder is probably set rather loose. I'm sure your original builder had a reason?

    I can't see if the Scott intake was made for a pre-48 or post-49 engine. If you have a pre-48 intake on a later block the internal venting is not as Ford designed, and that may be the reason of excess pressure in the crankcase. The baffling and compartments changed in 1949, and the intakes are part of the compartment system. The original "out" vent was a big tube that used under-car passing air to pull the fumes out and away. Yours is probably not there (can't see any in the pics). As suggested above, moving the PCV valve to the front of the intake and letting it pull dirty air from the crankcase up there might help reduce the pressure ( and oily air from getting into your distributor).
     
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  14. solidaxle
    Joined: Jan 6, 2011
    Posts: 394

    solidaxle
    Member
    from Upstate,NY

    I have installed an early S.Co.T. pre "49" on an 8ba. The only difference I found was the early manifold has additional mounting holes to the block. All the engine crank case venting lined up. I have a road draft tube in the front with the fuel pump location in the back as my air inlet and oil fill.
    The picture is another manifold I plan on using with an opening for the draft tube and oil fill in the front of the manifold. Since I'm running an electric fuel pump, the oil fill will be capped and I'll use the opening for the mechanical fuel pump location for the oil fill and engine crankcase breather intake.

    I think some your problem is the PCV valve. It can't function properly with the blower and is not removing the crank case air. when you are cruising or boosting.
    At idle I'm pulling 19-20 on the vacuum gauge.
    At cruse it's 12-15.
    Up a hill it's 10.
    Once I open the throttle under load, I'm making 5-6 lbs boost. IMG_20191010_123331.jpg
     
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  15. solidaxle
    Joined: Jan 6, 2011
    Posts: 394

    solidaxle
    Member
    from Upstate,NY

    I may back up a little, it looks like you are pulling the vacuum off the top of the blower, correct? My Vac/ Boost gauge taps off below the blower. So readings would be different. Install a temporary boost/vacuum gauge where your pulling from and see what the changes are.. You need to do this driving under load. Boost doesn't happen unless under load.
     
    Last edited: Oct 10, 2019
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  16. tubman
    Joined: May 16, 2007
    Posts: 4,411

    tubman
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    Boy, that sure looks like an intake designed for an 8BA. Did you add the openings for he road draft and oil fill tubes? I have seen some manifolds that had the bosses for those that were not drilled. Was this one of those?
     
  17. solidaxle
    Joined: Jan 6, 2011
    Posts: 394

    solidaxle
    Member
    from Upstate,NY

    8ba's have less bolts holding down the intake to the block then the early ones. I drilled and tapped the extra holes in my block just for insurance and fabbed a plate to push the blower more forward on the intake to clear the 8ba dizzy.
     
  18. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 5,556

    Bandit Billy
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    Before my rings fully seated I had a little blow by after a good run, mostly at the base of the air breather at the back of the intake (electric fuel pump). I faulted the blower for pushing air past the rings into the crankcase. Since then I have no issues. I did not install a PCV or raod draft tube but opted rather for a breather in my oil pan which in conjunction with the intake beater mentioned above, seems to do the trick.
    upload_2019-10-10_11-34-58.png
     
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  19. solidaxle
    Joined: Jan 6, 2011
    Posts: 394

    solidaxle
    Member
    from Upstate,NY

    Fordors has a good point, your pulling air at the same spot where it's coming in if your oil fill has a vented cap. Check the cap and fitment make sure it's sealed. If it's vented your PCV is pulling clean outside air.
     
  20. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    That is sooo shiny!!!! I don’t think this car has that oil pan breather.


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  21. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 5,556

    Bandit Billy
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    I added that breather to the pan. Welded nuts inside. My Red's headers fit right over the top of the breather. I learned to do it in Joe Abbins book on supercharging flatheads. Not my idea, I just steal stuff I like.
     
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  22. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    I don’t have that book. Will get it to learn a bit more.


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  23. solidaxle
    Joined: Jan 6, 2011
    Posts: 394

    solidaxle
    Member
    from Upstate,NY

    Here's a thought. If your draft tube hole is blocked off ( see pics ) Then air can not circulate down to crankcase. There is a tube that connects the bottom of the intake manifold passes through the lifter valley to the crank case.
    IMG_20191010_161620.jpg IMG_20191010_161543.jpg
     
  24. alchemy
    Joined: Sep 27, 2002
    Posts: 14,405

    alchemy
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    Don't seal that cap. As far as we can tell it's the only place this engine vents.

    And, if you add a breather on the side of your oil pan like Billy did (and I have one on my engine too), be ready for oil mist down there. Maybe cleanliness isn't your thing and you won't care. But if you need a spotless car, that pan breather ain't for you.
     
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  25. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    Ahh. I will check. That seems easy to chdck.


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  26. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

  27. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

    [​IMG][​IMG][​IMG][/IMG]

    The intake doesn’t seem to have any type of openings on the front, or the SCot covers them. Curious on last pic, what is that cross-shaped valve looking thing?

    The Joe Abbin book is like $125!!!



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  28. zz29
    Joined: Sep 7, 2017
    Posts: 215

    zz29
    Member

  29. Fordors
    Joined: Sep 22, 2016
    Posts: 2,222

    Fordors
    Member

    There is a zerk fitting opposite your finger, you can grease that rear blower bearing there.
    Also, in the last photo in the above post (@7:09 PM) that is a spring loaded pop-off valve. Some don’t use one if they run v-belts for the blower drive but in your case it won’t hurt anything to have one.
     
  30. solidaxle
    Joined: Jan 6, 2011
    Posts: 394

    solidaxle
    Member
    from Upstate,NY

     

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