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Technical Flathead first start up oil pressure

Discussion in 'Traditional Hot Rods' started by 36 Penny Coupe, Jan 26, 2018.

  1. 36 Penny Coupe
    Joined: Jan 7, 2014
    Posts: 169

    36 Penny Coupe
    Member
    from VA

    Let me start by saying I am not a Flathead expert in any way. Please forgive the novice questions. My car is 36 Ford with a 8BA FLATHEAD from a 49-53 Ford.
    It is being installed at a professional shop in my area. I purchased the engine rebuilt and never fired from a man who knew the shop owner and builder of the engine.
    It has adjustable lifters stainless valves and seats Egge pistons and all the good stuff inside. After the rebuilding it sat around for a few years.
    They started the car and engine sounds good. No internal noise. After running a short time the oil pressure at idle was only 20-25lbs. Did not test it at 2000 rpms.
    Is this acceptable? The oil pan did show major leaks and seal will need to be replaced. As well as timing cover. Sounds low to me.
    I am running an electric fuel pump only. Mechanical pump removed and hole blocked with a quality plate. I’ve read about the small hole in the pump rod bearing causing low pressure. Any ideas out there? I know Flathead Fords can vary in pressure.


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  2. Dak Rat
    Joined: Mar 8, 2006
    Posts: 376

    Dak Rat
    Member

    That little hole lubes the pump push rod. I removed that bushing and tapped it for a pipe plug. Don't know if it needs to be, but seemed like a good idea to me. Other wise the oil is just squirting out the empty hole.
     
  3. tubman
    Joined: May 16, 2007
    Posts: 4,876

    tubman
    ALLIANCE MEMBER

    If the engine was fully warmed up, that is an acceptable number. I like my flatheads to idle at 25 lbs and run at higher speeds at around 55 (the factory spec for the relief valve opening is 57 lbs). They will run fine at lower pressures, but I like to see my engines at least at factory specs. Get it fully warm and get back to us. BTW, what kind of oil pump do you have? I made a serious mistake and tried to save a few bucks and used an inferior pump from Speedway and will be replacing it with refurbished Ford pump.

    The oil loss through the push rod hole is a problem with the earlier engines; with post '49 engines, not to worry.
     
  4. 36 Penny Coupe
    Joined: Jan 7, 2014
    Posts: 169

    36 Penny Coupe
    Member
    from VA

    [​IMG][​IMG]
    I honestly do not know about the oil pump manufacturer Where could I get a good quality one ? Who makes a high volume pump that works with the stock oil pan?? The pan needs to come down to change the seal. Good time to survey the pump
    Here are some pics of the engine installed
     
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  5. Flathead Dave
    Joined: Mar 21, 2014
    Posts: 2,784

    Flathead Dave
    ALLIANCE MEMBER
    from So. Cal.

  6. tubman
    Joined: May 16, 2007
    Posts: 4,876

    tubman
    ALLIANCE MEMBER

    Unless your are doing some serious racing, a "High-Volume" pump is a big mistake. The best pumps are the original Ford ones.
     
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  7. flatheadtommy
    Joined: Oct 21, 2013
    Posts: 1,007

    flatheadtommy
    Member

    A good question would be, what viscosity oil are you running ? I've built many flatheads and I run 40 or 50 weight VR1 racing oil and never have any problems. Flatheads like heavier oil with their clearances.
     
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  8. 36 Penny Coupe
    Joined: Jan 7, 2014
    Posts: 169

    36 Penny Coupe
    Member
    from VA

    The engine has Rotella 15w 40 oil in it now.

    What are you guys using ? Maybe that’s part of the issue.


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  9. trey32
    Joined: Jul 27, 2014
    Posts: 250

    trey32

    I'd keep using rotella
     
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  10. tubman
    Joined: May 16, 2007
    Posts: 4,876

    tubman
    ALLIANCE MEMBER

    I use regular automotive 10/30. The additive package in diesel oil is just that : intended for diesel engines, and as such is not optimum for gasoline engines. Where people get off thinking using oil intended for diesel engines in regular automotive engines is a good idea is beyond me. I think they must be following the advice in my signature (which was originally intended to be humorous). If you have problems getting proper oil pressure in a rebuilt flathead with regular oil, you better have a talk with your machinist and forget about the diesel oil. Using oil of a higher viscosity than necessary can actually cause unneeded wear and higher oil temperatures.
     
  11. flatjack
    Joined: Feb 13, 2007
    Posts: 886

    flatjack
    Member

    It's the other way around.
     
  12. flatheadtommy
    Joined: Oct 21, 2013
    Posts: 1,007

    flatheadtommy
    Member

    Again I say run a straight weight oil such as a 40 or 50 weight not a multi viscosity A STRAIGHT WEIGHT OIL ! and Valvoline VR1 racing oil is great and it has a high zinc content that the bearings need. At least try what I recommend .
     
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  13. flatjack
    Joined: Feb 13, 2007
    Posts: 886

    flatjack
    Member

    Nonsense. I've been running 10W 30 in my engine for 20+ years. It's not the bearings that need the ZDDP, it is the camshaft and there is still plenty of it in todays oils.
     
  14. Glenn Thoreson
    Joined: Aug 13, 2010
    Posts: 78

    Glenn Thoreson
    Member
    from SW Wyoming

    I don't see that you have a problem if the pressure was checked at full operating temperature ( hot ). 20 lbs hot is good pressure at idle. I run Quaker Sate 10W-30 high mileage oil in my 8CM engine. It has added zinc, as do the other oils made for high mileage cars. Never a problem. If you have pressure at idle it means oil is flowing and that's all that matters.
     
  15. tubman
    Joined: May 16, 2007
    Posts: 4,876

    tubman
    ALLIANCE MEMBER

    Jack. We agree on this anyway. I will defer to you on the fuel pump push rod issue, because I only run stock pumps (I had a bad experience with an electric pump once).
     
  16. flatjack
    Joined: Feb 13, 2007
    Posts: 886

    flatjack
    Member

    The 59 and earlier engines had a solid rod bushing, so no possible pressure loss. The 8BA's had the small hole in the bushing. Not sure how much removing the rod would affect pressure. Maybe sometime I can check it out on my test rig.
     
  17. flatjack
    Joined: Feb 13, 2007
    Posts: 886

    flatjack
    Member

    Actually when the 8BA was introduced in trucks in 1948, there was no push rod bushing, just a hole drilled in the block and a rather large oil passage thru. The pushrod definetly needed to be in place on these engines. There was also a hole that was plugged at the back of the block that had a plug like the earlier engines. The very early parts books for these engines does not list a bushing.
     
  18. 19Fordy
    Joined: May 17, 2003
    Posts: 6,738

    19Fordy
    Member

    Your 8BA pressure at idle is fine. Will increase when you're
    driving down the road. 8BA's without the push rod does not affect oil pressure.
    However, lot of oil will splash up where the push rod used to be. To alleviate that
    you can fasten a rod to the bottom of your block off plate just long enough to rest on the fuel pump push rod opening in the block when you install your block off plate. Photos below show a similar idea where I replaced the fuel pump with homemade oil fill. Works great and makes it easy to fill engine with oil.
     

    Attached Files:

    Last edited: Jan 27, 2018
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  19. flatjack
    Joined: Feb 13, 2007
    Posts: 886

    flatjack
    Member

  20. weathrmn
    Joined: Apr 15, 2008
    Posts: 307

    weathrmn
    Member

    without the fuel pump rod in the 8ba or merc 8cm, the oil volume is affected along with pressure
     
  21. 36 Penny Coupe
    Joined: Jan 7, 2014
    Posts: 169

    36 Penny Coupe
    Member
    from VA

    Thanks so much for the pictures. Great idea for the pump rod and oil fill cap.


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  22. flatjack
    Joined: Feb 13, 2007
    Posts: 886

    flatjack
    Member

    The question is, how much?
     
  23. 19Fordy
    Joined: May 17, 2003
    Posts: 6,738

    19Fordy
    Member

    Last edited: Jan 27, 2018

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