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Oil Pressure on Flathead Ford V8

Discussion in 'The Hokey Ass Message Board' started by Hot Rodz R Us, May 28, 2010.

  1. Hot Rodz R Us
    Joined: Oct 19, 2006
    Posts: 920

    Hot Rodz R Us
    Member Emeritus

    Buddy of mine just got a 39 Ford P/U, fresh Flathead with about 1000 miles. Runs pretty cool at 175 degrees.....question is, what is the oil pressure on one of these motors suppose to run ??? We never have had one of these, just wondering in good cond., what to expect.....any and all advise would be appreciated

    Picture 090.jpg
     
  2. InPrimer
    Joined: Mar 10, 2003
    Posts: 778

    InPrimer
    Member

    Have a 52 flatty oil at 20psi idle. not much more than 35 when goin down the road PS its stock
     
  3. DAVEG2
    Joined: Feb 27, 2010
    Posts: 332

    DAVEG2
    Member

    I have a stock rebuilt '37. 20 lbs at idle. 30-35 on the road.
     
  4. Hot Rodz R Us
    Joined: Oct 19, 2006
    Posts: 920

    Hot Rodz R Us
    Member Emeritus

    Whats a good weight oil to run ?? also add Lucas ??
     

  5. tjelwood
    Joined: Jun 27, 2006
    Posts: 164

    tjelwood
    Member
    from oklahoma

    I run valvoline 20w50 with Lucas in my flatheads
     
  6. moefuzz
    Joined: Jul 16, 2005
    Posts: 4,950

    moefuzz
    Member

    In southern warm climates, Run a straight 40 weight if you want good oil pressure, Thats what old Henry recommend from day one.



    Also, new oils are hard on old engines because they don't contain zddp.
    It has been regulated out of the oils.

    Shell Rotella 40 or Chevron Delo 40 weight are made for diesels which ironically, the govt has not regulated the zddp out of them.

    Worse case scenario is the above (diesel) brands in 20-50 which still contain zddp due to the fact they are for diesels.



    Good stuff.



    .
     
    Last edited: May 28, 2010
  7. R Pope
    Joined: Jan 23, 2006
    Posts: 3,309

    R Pope
    Member

    Back in the day, a flathead truck that had any pressure at all was an oddity. They don't seem to need much!
     
  8. I wouldn't say a Model A is 1/2 a Flathead V8, not even close. A 9-N/8-N is more 1/2 a Flathead V8.:rolleyes:
     
  9. 56 Rum Runner
    Joined: May 24, 2010
    Posts: 55

    56 Rum Runner
    Member
    from Missouri

    Mine is a '53 motor in a '30 Model A. It was completely rebuilt and currently has about 700 miles on it. It holds 20+ at idle and 50+ running down the road. I run straight 40 weight.
     
    Last edited: May 28, 2010
  10. I have heard running an oil filter can drop it by as much as 10PSI also.
     
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  11. moefuzz
    Joined: Jul 16, 2005
    Posts: 4,950

    moefuzz
    Member



    Well then somebody better tell old Henry not to put any more canister style oil filters on any of those brand spanking new post war Flatheads,
    And it better be darn quick to, -otherwise he might install them on 2 or 3 million more new Flathead powered cars and trucks before he introduces the all new Y block. (oil filters extend engine life)



    .
     
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  12. srosa707
    Joined: Jun 5, 2005
    Posts: 1,573

    srosa707
    Member
    from Sacramento

    Mine has looooow pressure, but thats cause its worn out! Your good with 5-10 if thats all you got. Id be happy to keep 5lbs on my gauge :0
     
  13. Ha, hearing ya, can anyone confirm the myth??? Dont disagree on the extension of life point. But given its not a full flow design its probable that oil pressure reduction could happen.
     
    Last edited: May 31, 2010
  14. I've got 60lbs at idle and 70-75lbs driving. Engine is stock C59A.
     
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  15. 39 chevy kustom
    Joined: Aug 9, 2008
    Posts: 427

    39 chevy kustom
    Member

    mine is a 53 8ba orig. in my 53 with the canister oil filter, 3 qts rotellia 40 , 2 qts lucas runs about 40 lbs going down the road. shows 0 on stock guage at idle . I worried about this for awhile but if it were a problem the engine should have had real issues by now. it does not smoke , knock or rattle. so I run the crap out of it.
     
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  16. jetmek
    Joined: Jan 12, 2006
    Posts: 1,846

    jetmek
    Member

    depends on what pump is in it...the early 'long' pump is good for about 30lbs at speed. later style 8ba pump should make 60 at speed on a fresh engine. stock canister filters are practially worthless for what little oil gets filtered
     
  17. oldnintyseven
    Joined: May 26, 2011
    Posts: 20

    oldnintyseven
    Member

    my 8ba has 40 at idle cold 5 at idle hot and 60 on road cold and 25 on road hot
     
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  18. George Miller
    Joined: Dec 26, 2008
    Posts: 413

    George Miller
    Member
    from NC usa

    Back in the day flat head V8's in the hot summer weather had very little oil pressure at idle, maybe 5 lbs. They also like to vapor lock. You could fix that by increasing the length of the push rod for the fuel pump. Most of the time they were worn from running on the cam.
     
  19. Ole don
    Joined: Dec 16, 2005
    Posts: 2,915

    Ole don
    Member

    I rebuilt an 8 BA about ten years ago. It ran a stock oil pump, and an almost full flow filter system. I ran Rotella 15W40 all the time because its the right stuff and you can buy it anywhere. It ran 60 cold, 45 to 55 at highway speeds and 5 to 15 at hot idle. In high school, a buddy had a 41 sedan that had a hot idle of 0 to 3. It was the most reliable best running car any of us had.
     
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  20. sunbeam
    Joined: Oct 22, 2010
    Posts: 5,224

    sunbeam
    Member

    I looked in my old motors manual I've never seen them rated by MPH 30 @ 30 for a V8-85 in 1937.
     
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  21. kwolf
    Joined: Apr 6, 2006
    Posts: 22

    kwolf
    Member

    My fairly young 59AB runs 63-64 lb at 2500 RPM, hot idle 35 lb. This is with full floating rod bearings, 8BA oil pump... Both oil pressure valves in place.
    20-50 oil, full flow filter (Well, 3/4 full)

    Karl
     
    Last edited: Feb 26, 2014
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  22. blowby
    Joined: Dec 27, 2012
    Posts: 7,547

    blowby
    Member
    from Nicasio Ca

    Mine was super low, maybe 20 cold, revved up. I stretched the relief valve spring, upped it 15lbs across the board. Spring probably shot, need to get a new one if it sacks out again.

    Going to add a filter and see how much it drops.
     
  23. Aviator
    Joined: Apr 13, 2008
    Posts: 257

    Aviator
    Member

    Mine is 0 at hot idle and 30 on the road running 40 weight. No problems. An old man told me to forget the oil pressure gauge and watch the girls. It seems to work. Today's modern engines have made us oil pressure phobic


    Posted using the Full Custom H.A.M.B. App!
     
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  24. Steves46
    Joined: Sep 23, 2008
    Posts: 440

    Steves46
    Member
    from Florida

    Mine runs between 0 to 5 at hot idle and 30 to 35 cruising. I use 20-50 oil.
     
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  25. mista
    Joined: Nov 24, 2015
    Posts: 137

    mista
    Member
    from Finland

    Im losing my mind with my 221 right now. Rebuild engine as far as i know. Never driven. Started it but no oilpressure.

    I took the oilpan off and packed the oilpump with the 80w90 and filled the engine with 10w40. 4 quarts as told. Still no readings at the gauge. When i take the gauge off and start the oil is flooding from the hole but it is not squirting it to the roof.. So i guess someking of flow there is but no pressure. I put the gauge back and started the engine and let it run about 30-60sec and gave it little revs time to time. No pressure.

    Today i took the intake off and chekced the pressure valve. Nothing i see is wrong even though this is my first time dealing with the flathead v8 so all the advises are appreciated.. Please help me what should i do next or will i just have to buy a new oilpump? The bottom flange / head / cover had some wearing from rotating gear..
     
  26. tubman
    Joined: May 16, 2007
    Posts: 5,643

    tubman
    ALLIANCE MEMBER

    I had the same problem with a '53 Mercury I tried to fire for the first time; it would flow oil out of the unblocked port but wouldn't build pressure, even after a looong (well, it seemed like it to me) time. I replaced the oil pump with a known good one and all was well. I had good pressure after about 15 seconds of cranking. I checked the one spec given in the manual (gear end play clearance) and it was good. After a close visual inspection, I still couldn't see anything wrong. It went in the questionable pile.

    If you are going to replace the pump, consider using a later, 8BA style pump, as they are much better. You may have to do something with the pickup and external relief valve (the 8BA relief valve is internal), but it's a worthwhile upgrade.

    Also, I have heard that you should pack the pump with Vaseline. The story here is that it is thick enough to get the pressure going, but will dissolve more quickly than regular grease. I've never done it (used regular chassis grease), but it sounds reasonable.
     
  27. mista
    Joined: Nov 24, 2015
    Posts: 137

    mista
    Member
    from Finland

    Is there something different with the pickup of the newer style oilpump? Does it fit 1937 59A oilpan? Has anyone experience about speedway motors oilpump ? http://www.speedwaymotors.com/Speedway-Flathead-Ford-Oil-Pump-Standard-Volume,11215.html

    is the relief valve suppose to be modified to be closed or open?
     
  28. tubman
    Joined: May 16, 2007
    Posts: 5,643

    tubman
    ALLIANCE MEMBER

    For information on an 8BA pump in a 21 stud flathead, check this thread out : https://www.fordbarn.com/forum/showthread.php?t=39583. Also, I have heard that there is a quality problem with the Speedway pumps; I hope not, because I have one in my new 8BA build. For stuff like this, you should really check out the "Ford Barn"; it's all about flatheads and doesn't move as fast as this forum. If you go over there, you should be able to research all aspects of this to your hearts content.

    Oh, one last word of advice : don't be coerced into using a high-volume pump. They are not needed and can cause problems on an otherwise stock engine.
     
    Last edited: May 29, 2017
  29. image.jpeg I have built many flatheads(over 20 for myself and customers) and have used logic and experience to make this assumption:This is my opinion and my opinion only but I believe that 10 pounds of oil pressure for every 1,000 RPM is sufficient.I do NOT use the partial flow oil filter and change my oil very regularly. Oil is cheap; engines are NOT!
     
    Rick Hegdahl likes this.

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