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Hot Rods Flathead build advice needed

Discussion in 'The Hokey Ass Message Board' started by Desoto291Hemi, Oct 22, 2019.

  1. fullhouse296
    Joined: Jan 30, 2009
    Posts: 388

    fullhouse296
    Member
    from Australia

    The 4" crank should have small square dimple on smaller counterweight , also , the oil gallerys will usually have pressed in welsh plugs that will need to be removed for cleaning and then get tapped threads for screw in plugs . Ford 3.75 stroke cranks are mostly , screw in oil welsh plugs .
     
  2. Yes,,,,,,Mercury crankshaft for sure!
    I plan on replacing the plugs with threaded pipe plugs

    Tommy
     
    Boden likes this.
  3. Johnboy34
    Joined: Jul 12, 2011
    Posts: 1,333

    Johnboy34
    Member
    from Seattle,Wa

    Did the broken rings score the cylinders much? If theres no cracks you'll have a nice motor! I would recommend only boring as little as needed to help not to have overheating issues. The lower end is nice shape for sure. Did you take the oil pump apart and mic the gears?

    Sent from my SM-G900V using The H.A.M.B. mobile app
     
  4. Flathead Dave
    Joined: Mar 21, 2014
    Posts: 3,062

    Flathead Dave
    ALLIANCE MEMBER
    from So. Cal.

    Spend the extra few dollars to get a magna flux done.
     
  5. tubman
    Joined: May 16, 2007
    Posts: 5,313

    tubman
    ALLIANCE MEMBER

    Looks like you scored, Tommy. I'll have my fingers crossed while the block is being tested. As to bore, as long as you have to buy pistons, I'd go to 3 5/16" (.125 overbore). The pistons are about the same price, and a 276" engine is sweet. If it overheats, there are other issues that need to be addressed. Also it leaves enough "meat" in the cylinders for 3 or 4 more rebuilds. Two of the last three engines I've built have been 3 5/16" with no problems.

    Read my tag line.:D
     
    throughbeingcool likes this.
  6. Well,,,I got some more done on my Flathead.
    I got all the valves out and the lifters,,,,it took about 2 hours all together.
    It is new to me,,and the first ones came kind of slow,,,I didn’t want to do anything to damage the block.
    I got the hang of it after the first 45 minutes,,then it went much quicker.
    The lifters came out very well,,,a few were tight,,,,,but none were really stuck.
    I haven’t put a wire brush to the decks yet,,,but they seem to be very well.

    Tommy
     

    Attached Files:

  7. Here are some pics of the cam area and the camshaft itself.
    Seem to be very decent shape.

    Tommy
     

    Attached Files:

  8. tubman
    Joined: May 16, 2007
    Posts: 5,313

    tubman
    ALLIANCE MEMBER

    My eyes aren't what they used to be, but I can't see any "part number" cracks.
     
  9. I did find something unusual,,,and I wanted to show you guys and ask about it.
    Some of the valve guides were different.
    Some had a solid body and some had a groove machined into it and had a rubber seal in the groove.
    In the pic the rubber seal is easily visible.
    It has square corners and is still pliable,,,the I.d. is square as well.
    It might have formed into a square shape after 70 years ,,I’m not sure.
    Some were on the intake side,,,some were in the exhaust.
    There is 9 with the rubber,,,7 with the solid body,,,,,any ideas?

    Tommy
     

    Attached Files:

  10. Here are pics of a lifter.
    This one is typical of all of them,,,they all seemed in about the same condition .
    Not much wear on the top,,,or sides.
    The bottom has typical wear just like any old lifter would be.
    What amazed we is they are hollow,,,,I always assumed they were solid !
    The bottom is a hardened insert,,,,really sound design.
    Some really good engineer work for back then,,,,really better than today’s in some respects.

    Tommy
     

    Attached Files:

  11. I still have a few other things to remove and then it is off to the shop to be checked for any cracks and such.
    I am not gonna bore it yet,,,,still deciding how far to go.
    I was thinking about .060,,,,but,,,,.125 sounds good as well.
    I just want to make sure it has plenty of meat left in the cylinders.

    Tommy
     
  12. Another question.

    I would really like to get the compression to around 10 to 1.
    Is this possible?
    I have read where most of the aftermarket heads get it to about 9 to 1.
    What would I need to do to increase it,,,,in a safe way,,,nothing radical?

    Tommy
     
    Boden likes this.
  13. Here are pics of the cam bearings.
    The number 2 and 3 bearings are perfectly aligned with the oil galley.
    The number 1 was just barley over the hole,,,,but I guess they don’t need a ton of oil
    But,,,,is that where the front main bearing gets its lube from?
    Either way,,,the bearings still looked great.
    And I don’t think it had tried to spin either,,,,the cam journal is perfect and so is the cam bearing.

    Tommy
     

    Attached Files:

    Aaron D. likes this.
  14. acme30
    Joined: Jun 13, 2011
    Posts: 173

    acme30
    Member
    from Australia

    Whilst you can have the rubber seals on inlet and exhaust guides lots of Flatheads don't have them on either. Guys that put them on usually only do so on the inlet guides. And yes square sides are correct for the seals.
     
  15. Johnboy34
    Joined: Jul 12, 2011
    Posts: 1,333

    Johnboy34
    Member
    from Seattle,Wa

  16. alchemy
    Joined: Sep 27, 2002
    Posts: 16,060

    alchemy
    Member

    Bore it the MINIMUM needed to clean up the cylinders. It looks like you have a very clean virgin engine, and it probably won't need too much to make it round again. If it needs .060 I would be surprised. If the machinist says it would be good at .020 I'd do that. Make your horsepower with heads and cam. Maybe a little cleanup porting of the intake and exhaust ports if you are comfortable. Read posts by Mike Bishop.

    All the parts you've pulled out so far point to a nice engine that's never been messed with at all. The different guides are intake (with seals) versus exhaust (no seal).
     
    throughbeingcool likes this.
  17. jimmy six
    Joined: Mar 21, 2006
    Posts: 7,623

    jimmy six
    Member

    Why is it a “stroker” if it’s a stock stroke crank?
     
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  18. alchemy
    Joined: Sep 27, 2002
    Posts: 16,060

    alchemy
    Member

    Stroked over Ford size. Ford was 3-3/4" and Merc was 4".
     
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  19. Atwater Mike
    Joined: May 31, 2002
    Posts: 10,297

    Atwater Mike
    ALLIANCE MEMBER

    4" crank:
    In a Ford, it's a 'stroker'...in a Merc, it's a 'stocker'. heh, heh
     
  20. 8flat
    Joined: Apr 2, 2006
    Posts: 1,376

    8flat
    ALLIANCE MEMBER

    Unfortunately with a flathead, to get a compression ratio that high means you need to reduce the size of the head's chamber so far that it'll restrict your airflow from the valve over to the cylinder bore. Completely different than engines with valves-in-head. So.... you may not want to go higher than somewhere around 8.75 IIRC before you get to a point of diminishing returns....where higher CR gets negated by loss of flow.
    This is all off memory so I may be a little off on that 8.75 number. I think that's where mine ended up after we CC'd the heads and did a valve relief job.
     
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  21. 8flat
    Joined: Apr 2, 2006
    Posts: 1,376

    8flat
    ALLIANCE MEMBER

    PS very cool thread, reminds me when I tore down my 8BA with 40k original miles (shown in avatar after rebuild), it's like a time capsule. Best part is my grandpa purchased it brand new in '51, he and I worked on it, was a perfectly good running engine but a wrist pin came loose and wore a groove in one bore. Love these flatheads! Good luck on your project, keep us updated.
    Gary
     
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  22. Thanks guys,
    Johnboy,,,the Reds link was the info I was looking for,,,it answered my questions.

    Alchemy,
    The bores still look great,,,just some wear at the top,,.020 or .030 will clean it good.

    8flat,,,Gary,
    That is info I need to know.
    I didn’t know if 10 was possible,,,maybe I can get it close to 9 to 1.

    Thanks guys for all the insight,,,I appreciate all of it.

    Tommy
     
  23. Now let me get this clear.
    The valve seal is in the valve guide body,,,not on the valve stem.
    The valve guide has a groove on the body o.d.,,,,and the seal goes into that groove,,,there is no seal on the stem itself? Correct?

    Tommy
     
  24. Boden
    Joined: Oct 10, 2018
    Posts: 733

    Boden

    Not nessecary but good idea. I just put normal plugs in mine


    Sent from my iPhone using H.A.M.B.
     
  25. Boden
    Joined: Oct 10, 2018
    Posts: 733

    Boden

    Deck block to 0 deck. And milk max out of heads. And if ur using stick heads. Get a set of ford heads. They have smaller combustion chambers than the mercury. On alum heads I would milk the shi* out of them. Haha


    Sent from my iPhone using H.A.M.B.
     
  26. Yes...

    And it's been apart before; one of the main bearings is dated 11-61.
     
  27. alchemy
    Joined: Sep 27, 2002
    Posts: 16,060

    alchemy
    Member

    Don't deck the block at all. There's not enough thickness there to play with. Only deck the minimum if its warped.

    And, do not run a tap in the headbolt holes. Best to use a wire brush in there or maybe cut a kerf in a stock Ford head bolt to use as a cleanup. The original threads in the block are close tolerance and if you run a tap through them you will get weeping of coolant up the threads from the water jackets.
     
  28. Getting ready to remove the rear gear that drives the oil pump.
    I am assuming that I will need to use a slide hammer to get the gear and shaft from the back side of block ?
    The shaft has 3/8 threads in it.
    Tommy
     
  29. Just a couple questions for you for thinking ahead.
    What are you going to do for Camshaft? That conversation can and will take weeks, lots of opinions out there.
    What is this motor going into?
    What transmission are you planning to put behind this? stick, auto, 3,4 or 5 speed?
    Are you going to look at a lightened flywheel?

    I see that it has the Merc Oil pan. I have heard that they can be a problem to fit up against some of the Ford bellhousings. They made a Merc specific Bell housing, is stamped steel sheetmetal. Also the starter mount plate for Merc is different from Ford.

    Just a cautionary note to be selective and informed when choosing the pan and bell housing combination.
     
    Last edited: Nov 5, 2019
  30. Hi Jr,
    To your questions.
    I got a very nice original flywheel for it now,,,it is very clean.
    Has some wear on it,,,,about.010 deep in a uniform pattern where the disk was.
    I plan to have it surfaced,,,and it should be back to perfect condition.
    The ring gear is perfect,,,,no bad teeth at all.
    I also plan to have it drilled for a Borg and Beck pattern,,,I just like those better.

    The bellhousing is a very good condition Mercury steel unit.
    I plan to have it cleaned and blasted,,,then probably paint it red like Lakewood,blowproof,,,,just for laughs!

    The transmission will be a 4 speed.
    I’m not sure which one yet.
    I might go with a Mopar,,,4 speed overdrive for an A body. I have several!
    It has a 3.09 first gear,,and a .71 overdrive

    Or,
    I might go with a really nice Borg Warner T10 that I have,,,it is a 1962 model that I have completely gone through .
    All new insides,,,only first gear and the main shaft,,and reverse gears are used,,,,all else is new inside.
    It is a 2.54 first gear unit now.
    But,,,,I will probably use the Mopar because of weight,,and the low first gear.
    The 833 is all aluminum housing,,,the T10 is cast iron.

    On the camshaft,,,I am still reading about it.
    Probably go with an Isky,,,or maybe a Schneider.
    What are the good choices for me?

    This engine will go into a hot rod,,,,a Deuce, or a California Kid body that I am looking at.

    I am still reading all the advice that you guys post here,,,,nothing is in stone yet.
    Well almost nothing,,,,it Will be a Flathead with a 4 speed in a hot rod.

    Tommy
     
    Surfcityrocker likes this.

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