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Hot Rods screw in freeze plugs

Discussion in 'The Hokey Ass Message Board' started by silent rick, May 21, 2018.

  1. silent rick
    Joined: Nov 7, 2002
    Posts: 3,715

    silent rick
    Member

  2. squirrel
    Joined: Sep 23, 2004
    Posts: 40,269

    squirrel
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    just gotta buy the right block

    2livbpk.jpg
     
  3. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 768

    CNC-Dude
    Member

    I've done several non Boss 302 for some guys. The taps are pretty expensive. You could still buy the plugs from Ford Motorsports a few years ago.
     
    chryslerfan55 likes this.
  4. VANDENPLAS
    Joined: Dec 14, 2009
    Posts: 1,044

    VANDENPLAS
    Member

    I like that block squirrel, whatssit?

    Never really heard of freeze plug failure unless they are installed wrong

    Just like “ anything can be a dildo if your a big enough slut box”

    Anything can be a frost plug with the right tap, but a tap that size is gonna he worth a few bucks
     
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  5. squirrel
    Joined: Sep 23, 2004
    Posts: 40,269

    squirrel
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    Boss 302

    Sent from my Trimline
     
  6. Deuces
    Joined: Nov 3, 2009
    Posts: 15,260

    Deuces
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    from Michigan

    That's what I thought..... :cool:
     
  7. RichFox
    Joined: Dec 3, 2006
    Posts: 9,280

    RichFox
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    I did tap a GMC block once and make brass plugs with hex heads. Looked cool. Didn't do anything else any better.
     
    Vanness, williebill and squirrel like this.
  8. DDDenny
    Joined: Feb 6, 2015
    Posts: 9,841

    DDDenny
    Member
    from oregon

    I had some spares that came with my Rodeck block, only have two left, gave one to a local dirt modified guy that needed it, not letting go of them because they are no longer in business.

    20180521_154639.jpg


     
  9. seb fontana
    Joined: Sep 1, 2005
    Posts: 5,428

    seb fontana
    Member
    from ct

    I got me one a them [69-70] Boss 302..Been under the bench for 30 years, gonna build it some day..
     
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  10. DDDenny
    Joined: Feb 6, 2015
    Posts: 9,841

    DDDenny
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    from oregon

    It ain't gonna build itself;)
     
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  11. Mike VV
    Joined: Sep 28, 2010
    Posts: 1,137

    Mike VV
    Member

    I've done half of my Stude block. It's a pain in the butt.
    As noted, the tap isn't cheap.
    And with the Stude block, you need a standard tap to start the threads...then a short tap to finish the threads to the correct size to get the plugs installed to a good position.
    I'm doing mine in two steps, first step, then shorten the tap and finish the threads. As I said...a pain in the butt.

    Mike
     
  12. fauj
    Joined: Jun 25, 2009
    Posts: 667

    fauj
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    1. 57-60 Ford F100s

    My buddy and I used some very large pipe taps to put them in his 351C block many years ago. For some reason 1-1/4" npt sticks out to me, but cannot remember exactly. I do know that we used two taps. One was unmodified and used to start the threads and the other had about the bottom half ground off of it. Got the taps for free on a job I had done that provided way more taps than was needed and they were going to toss the taps when the job was done.
    Not being a Cleveland guy, I was told they they help strengthen the block somewhat as well. They look very nice and doing it yourself you can adjust the depth of the plugs so to speak.
     
  13. LM14
    Joined: Dec 18, 2009
    Posts: 1,113

    LM14
    Member
    from Iowa

    I had one that sat under my bench for about 25 years. Sold it last fall. Figured getting $1000 for a 030 over block that needed a sleeve was better than something to walk around another 25 years. Money went into the '32 Ford 5 window fund so it was a good cause...
    SPark
     
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  14. Mr T body
    Joined: Nov 2, 2005
    Posts: 1,651

    Mr T body
    Alliance Vendor
    from SoCal

    Gotta do this on the 545 going in the '32. Press in freeze plugs tend to pop out over 700 horse and using the block mounting pads.
     
  15. silent rick
    Joined: Nov 7, 2002
    Posts: 3,715

    silent rick
    Member

    for the most part, they go un-noticed. but when they are noticed, it's a hint to something special that hides underneath, performance. i don't know how much strength is added when using them, i'm thinking it was more preventative.
    less chance to puke out and douche the track in front of the rear tires during a race. and they look cool.
     
  16. porknbeaner
    Joined: Sep 12, 2003
    Posts: 40,355

    porknbeaner
    Member

    Soft plugs seldom fail. I have never heard a satisfactory explanation for why Ford used screw in core plugs in the Boss 302 other then to set that block apart from other small block Ford blocks.

    It is a cool idea and looks cool but there is no real logical reason for it. Perhaps to make it easier to assemble it certainly takes less finesse to screw a plug in than it does to drive one in. ;)
     
  17. silent rick
    Joined: Nov 7, 2002
    Posts: 3,715

    silent rick
    Member

    i heard it was because the boss 302 was destined for the 5.0liter trans am racing, a screw in plug was less likely to fail causing leakage and causing a spin out on the track.

    of course, i have no logical reason for wanting to do so other than i think they look cool.
     
  18. squirrel
    Joined: Sep 23, 2004
    Posts: 40,269

    squirrel
    Member

    if you're just doing it for looks, you could turn down a threaded plug to fit inside a normal freeze plug :)

    super poser!
     
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  19. silent rick
    Joined: Nov 7, 2002
    Posts: 3,715

    silent rick
    Member

    that's my middle name jim
     
  20. HiHelix
    Joined: Dec 20, 2015
    Posts: 378

    HiHelix
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    They are sand casting clean outs... not freeze plugs...
     
  21. RmK57
    Joined: Dec 31, 2008
    Posts: 649

    RmK57
    Member

    Might be worth while in a supercharged application. I can see it as a safety feature more than anything. IMG_2525.JPG
     
  22. squirrel
    Joined: Sep 23, 2004
    Posts: 40,269

    squirrel
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    ......especially the threaded plugs, eh? won't pop out when it freezes
     
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  23. Gerrys
    Joined: May 1, 2009
    Posts: 298

    Gerrys
    Member

    I guess in a supercharged or turbo application could prevent the plugs popping with a failed head gasket.
     
  24. Deuces
    Joined: Nov 3, 2009
    Posts: 15,260

    Deuces
    Member
    from Michigan

    Wasn't the 289 hi-po block done up the same way???? Screw in freeze plugs and 4-bolt mains????
    Just curious.....:confused:

    I also read somewhere that the factory installed TRW Forged pistons were prone to cracking around the wrist pin area on the Boss 302....:eek:
     
  25. RichFox
    Joined: Dec 3, 2006
    Posts: 9,280

    RichFox
    ALLIANCE MEMBER

    Lots of guys, myself included, put a strap across the Welsh plugs. Held down by a couple of 10-32 screws, the strap prevented the plug from popping out. These were cup type plugs, but I guess you could use a set screw in the strap for expansion plugs.
     
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  26. Actually, they are core plugs. The sand might be cleaned out through them, but the holes are where the sand cores, that form the hollow parts of the block, rest on the outer part of the mold
     
  27. Atwater Mike
    Joined: May 31, 2002
    Posts: 8,569

    Atwater Mike
    ALLIANCE MEMBER

    There was a fat guy at the shop one night, blowing off how fast his 'rat motor' was.

    That thing had SO MUCH H.P. that when he wound it up the first time..."It blew all the freeze plugs out!"
    I ushered him out, before he 'blew the radiator off with it!'
    Uh...I prefer the cup type welsh plugs...
     
  28. LM14
    Joined: Dec 18, 2009
    Posts: 1,113

    LM14
    Member
    from Iowa

    The logic was it took a thin wall casting and made it stiffer. Less deflection under stress, truer bores and more longevity. Simple.

    No, the 289 HiPo was a 2 bolt block with normal freeze plugs. It had thicker webs than a normal block but no screw in plugs.

    SPark
     
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  29. saltflats
    Joined: Aug 14, 2007
    Posts: 8,590

    saltflats
    Member
    from Missouri

    Funny my next build won't have freeze plugs. :eek:
     
    silent rick likes this.
  30. Deuces
    Joined: Nov 3, 2009
    Posts: 15,260

    Deuces
    Member
    from Michigan

    Ok, thanks....
     

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