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Technical Ford Flathead Head Bolt Question

Discussion in 'The Hokey Ass Message Board' started by Ziggster, Feb 28, 2019.

  1. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    I have a Ford Canada flathead C69, that is being rebuilt. I plan on reusing the factory iron heads and head bolts as my machinist advised against going with studs. I can't find much info on head bolts for this series of engines (pre 8BA). The engine was rebuilt at some point by an authorized Ford rebuilder using bolts, but what I find interesting is that there were three different lengths of bolts used. I see for the 8BA series only two different lengths were used (1.94" & 2.62"). I have qty 4 that measure 2.37" and seem to be located in positions 11 and 14 in the pic below based on the amount they protrude below the head surface as they match that distance of the other bolts which are also 1.94" and 2.62". My heads are marked as C7RA-A. Can anyone shed light on this "anomaly"?
    image.jpeg
     
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  2. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,358

    dirty old man
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    Just a suggestion, but try screwing the bolts in the head bolt holes in the block in those 2 positions 11&14 and see if there's a shorter hole there than the holes the other longer bolts go in. The shorter length may be preventing bottoming out in shorter holes.
    Been at leas 50 years since I had the heads off a flathead and I don't remember for sure. At least my reply will boost you back to the top:)
     
  3. rusty valley
    Joined: Oct 25, 2014
    Posts: 924

    rusty valley
    Member

    look at the thickness of the head. you will see the bottom is thinner than the top. short ones go in the bottom, middle in the middle, and long on the top. if your a new guy get familiar with van pelts web site. all the information you can think of is there, and mac van pelt is a great guy for buying parts and answering questions. happy motoring
     
  4. tubman
    Joined: May 16, 2007
    Posts: 4,597

    tubman
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    I have Edmunds heads on both of my 8BA's, and the are a bit thicker at the 11 & 14 positions than the stockers (ideally, they would have three different head bolt lengths rather than two). I checked them with a couple of the shorter stock head bolts and found that they screwed in about 5 turns, so I shrugged my shoulders and used them. No problems so far. Aluminum heads are usually torqued to only 45 ft/lbs so they should be fine. Iron heads usually get 65 ft/lbs, and I wouldn't be so sure.

    You might want to check this thread out so the heads won't move around on you if you are using bolts. It's not as important when using stock heads, rather than aftermarket aluminum, but still...

    https://www.fordbarn.com/forum/showthread.php?t=230469&highlight=aluminum
     
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  5. AngleDrive
    Joined: Mar 9, 2006
    Posts: 718

    AngleDrive
    ALLIANCE MEMBER
    from Florida

    I just did one about a year ago and forgot how I solved the issue. Head on over to the FordBarn and ask the question. They will shed light on your issue.
     
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  6. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,683

    Bruce Lancaster
    Member Emeritus

    Easier than measuring would be to just drop a long bolt first into a long hole then into an 11 or 14 without tightening and just see if they protrude the same. In general the Aanadian heads (C7RA-A and -B, iron and aluminum) are I think going to use the 3 types of stud as in USA.
     
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  7. alchemy
    Joined: Sep 27, 2002
    Posts: 14,745

    alchemy
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    Why bolts and not studs? Flathead Fords are common to get weeping around the threads of the bolt/stud, so you will need to use sealer. Every time you need to retorque the bolts you will disturb the sealer. Maybe letting the coolant leak past again.

    I like studs. Glue them in once and never need to disturb the sealant again. I use the stinky brown Permatex.
     
  8. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    Here are a couple of pics. The bolts protrude the same amount which is about 0.75". There are some variations in the length of similar length bolts, and some are marked with an "S", and others with an "H", although the size/shape of the letters vary. Going to try to see if I can clean them up a bit in my vibratory grinder using walnut shells.
    image.jpeg
    image.jpeg
     
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  9. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    Stopped at TSC in Ogdensburg this morning after picking up some parts I ordered and found they have some nice Grade 8 flange head bolts with shoulders that might be a good replacement from Hillman. They are a little too long compared to the stk bolts (2.75" vs 2.62"; 2.5" vs 2.37"; 2.0" vs 1.94"). Not cheap though.
    image.jpeg
    image.jpeg
     
  10. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    Checked on the bolts after about 4-5 hrs in the grinder/ polisher. The three on the left were in the polisher and the the three on the right as they were after coming out of the parts washer. The walnut shells are now pretty fine, so I might try changing it with some fresh stuff to see if helps a bit more.
    image.jpeg
     
    Last edited: Mar 2, 2019
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  11. Beanscoot
    Joined: May 14, 2008
    Posts: 1,223

    Beanscoot
    Member

    A wire wheel on a bench grinder might also work pretty well to clean those bolts.
     
  12. rusty valley
    Joined: Oct 25, 2014
    Posts: 924

    rusty valley
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    are you short a couple? i have plenty if you need any
     
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  13. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    That will be next step, and perhaps some sand blasting.
     
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  14. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    Yes, thanks for the offer. My machinist may have extras though. If not, I'll PM you.
     
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  15. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,358

    dirty old man
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    IMO, sand blasting bolts isn't such a good idea, and could possibly lad to galled threads. I believe a wire wheel with not too heavy of wire is about as agressive as you should get on a bolt.
     
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  16. 19Fordy
    Joined: May 17, 2003
    Posts: 6,561

    19Fordy
    Member

    Whatever you do, DO NOT USE A TAP to chase the block threads.
    DO NOT USE A DIE to clean the bolt threads.
     
  17. Kiwi 4d
    Joined: Sep 16, 2006
    Posts: 2,558

    Kiwi 4d
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    As said do not sand blast the bolts and do not use any form of cutting tools or you will be for ever chasing unstoppable leaks. Be patient and just use a wire wheel if you must use the original bolts . Myself I would use ARP studs ,spendy but they work along with a quality stud sealer.
     
  18. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,683

    Bruce Lancaster
    Member Emeritus

    Gun cleaning brushes will clean up the threads without loosening the fit. The holes are two grades tighter in thread fit than most bolts...if you can screw in the fasteners (when clean) with your fingers, someone has gotten at the holes with a standard machinist's tap and you will need some sealant AND you should set up the studs to vertical before final assembling heads.
     
  19. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    Now that my short block is finished, I've started looking at all the hardware needed to assemble the bits and pieces. I've ordered quite a bit of stuff from Roy Nacwicz, but they don't carry the head bolts I need. So, I figured no biggy, I'll just find them locally, but no luck either. Seems what I thought what should be "standard" bolts are not easily found. Any suggestions would be appreciated. I still do not want to use studs.
     
  20. tubman
    Joined: May 16, 2007
    Posts: 4,597

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    A couple of things have not been mentioned here, so I'll step forward. First all regular "hardware store" 7/16" bolts have 5/8" heads, not 11/16" like the original Fords (8BA bolts and the earlier nuts). I would imagine Ford had a reason for using this larger sized bolt head and the "traditional" headbolt covers (acorns) won't fit them. Next, I'm a firm believer of using the special hardened washers available from several sources when installing heads. In your situation, I would consider using 8BA head bolts, which are readily available if you look. The one thing I am unclear on (as I have no experience with pre-8BA engines) is whether the "special" thread profile used by Ford on 8BA bolts is compatible with the earlier block.

    I fully understand your desire to not use studs, as I have read horror stories about them and I have never had a problem with bolts on the several 8BA engines I have done. I do make a particular effort to make sure the heads are positively positioned on the block before torquing them. While this is more important with aftermarket heads with their oversize bolt holes, it may be helpful with stock heads as well. Check this out : https://www.fordbarn.com/forum/showthread.php?t=230469.
     
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  21. H&H tap all their blocks. Saw a picture on Instagram and confirmed with him..
     
  22. 19Fordy
    Joined: May 17, 2003
    Posts: 6,561

    19Fordy
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    Wonder what brand head bolts H and H uses and where they buy them?
     
  23. alchemy
    Joined: Sep 27, 2002
    Posts: 14,745

    alchemy
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    Well I ain't gonna. After fighting a fresh engine (built by a different shop) that weeped on many studs, I'll never tap a block, and will always use LOTS of goo to seal the studs,
     
  24. Truck64
    Joined: Oct 18, 2015
    Posts: 3,864

    Truck64
    Member
    from Ioway

    Thread chasers and bottoming taps are OK, no??

    What I mean by that is using the correct tool. Not the incorrect tool.
     
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  25. tubman
    Joined: May 16, 2007
    Posts: 4,597

    tubman
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    On 8BA's, all I use is a stock head bolt with 4 grooves filed in it. If the H&H guys have a special tap made to match some special bolts or studs, I'll go along with their procedure; otherwise, their stock just went down in my book. Also, applying great gobs of sealer has never been a recommended solution to any problem automotive I have ever run into.
     
  26. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    Just contacted TSC in Ogdensburg, NY. They only have s few of the Hillman bolts pictured above in stk but can order more when I drop by on Saturday.
     
  27. I repurposed my original studs, just cleaned them up with a brass brush. machine shop did the block holes & yes I warned them not to use a regular tap. So far it is holding up & that has been a while, no weeping around the studs.
     
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  28. Ziggster
    Joined: Aug 27, 2018
    Posts: 577

    Ziggster
    Member

    That was the plan but I'm missing some, some are too corroded for my liking, and machinist was going to try to get some extras from a friends, but that never happened, so here I am. Even Fabory, who I used to deal with as a supplier doesn't even list the 7/16" size bolts. Maddening to say the least.​
     
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  29. There is a guy up your way that rebuilds a lot of flatties. I don't recall his name tho, you might inquire around. A few years ago he made a trip down into ew Mexico & Arizona buying up engines. I'm sure he would have plenty.
     
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