Register now to get rid of these ads!

Hot Rods Hemi freeze plug question

Discussion in 'The Hokey Ass Message Board' started by shaunez, Feb 29, 2020.

  1. town sedan
    Joined: Aug 18, 2011
    Posts: 1,290

    town sedan
    ALLIANCE MEMBER

    Just one question, why? Because I don't know.
    You said the inside of the block is coated with glyptal. Wouldn't this interfere with heat transfer?

    As far as the plugs that fill the holes in the block go, I've never had a problem with steel, or brass, plugs with Permatex #2. But to each there own.
    -Dave
     
    Desoto291Hemi likes this.
  2. mickeyc
    Joined: Jul 8, 2008
    Posts: 1,063

    mickeyc
    Member

    I do understand now. These plugs were used for initial clean out after the casting process. So they are actually
    irrelevant as to protecting a block from freeze damage.
    This makes sense now that I recall an old 6cylinder chevy block I had cracked between two core plugs.
    Neither plug was disturbed, seems rust held them in place! Here in Louisiana of all places. Thanks for the clarification.
     
    gimpyshotrods and 57 Fargo like this.
  3. sunbeam
    Joined: Oct 22, 2010
    Posts: 4,914

    sunbeam
    Member

    Desoto291Hemi likes this.
  4. Yes!!!!


    Sent from my iPhone using H.A.M.B.
     
    gimpyshotrods likes this.
  5. Hombre
    Joined: Aug 22, 2008
    Posts: 1,030

    Hombre
    ALLIANCE MEMBER

    I am not sure everyone is familiar with the Mopar disc type Plug ( be it either freeze, core, sand removal or some other name I am sure they have been called). These damn things are for sure and for certain a huge pain in the butt. They do not install anything like a more common cup type plug, because of this they are prone to fall out under pressure. Once you get the hang of the correct way to install them they can be just fine ( at least that is my experience with them) but no matter they are I think a poor design from a user point of view. For me personally I use JB Weld to install these, once it sets up I am pretty sure it would take a small explosion to blow one of them out of the hole. Pictures:
    Cup plug.jpg
    Cup type

    Core Plug.jpg
    Mopar Disc type plug

    installed plug.jpg

    Correctly installed Mopar disc plug, you "MUST" expand these by hitting them in the center and forming that dimple.
     
  6. Hombre,
    That looks like a 440 block,,,I have never seen plugs like that in a 440 ?
    Were they very common ?

    Tommy
     
    racer-x likes this.
  7. BoogittyShoe
    Joined: Feb 18, 2020
    Posts: 330

    BoogittyShoe

    If you are still trying to get them in without the backside turning,
    and if you aren't worried about appearance,
    and if you don't mind "ruining" some nice plugs, (I use the "whatever works" approach),
    you could drill and tap about a 3/16" hole in it and put a screw in it long enough for the tab to catch. Maybe a nut on the back.
     
  8. seb fontana
    Joined: Sep 1, 2005
    Posts: 6,523

    seb fontana
    Member
    from ct

    Core support hole plug..The hole is the result of the core "supports" that maintain the distance between inside and outside cores where the casting material will build up when pored in forming the block, not originally designed for clean out. If block could be cast with out they would, but it does help with clean out of the core sand but also later when the ancient engines are resurrected. Lucky the engine in pic has side plates instead of plugs..
     

    Attached Files:

  9. seb fontana
    Joined: Sep 1, 2005
    Posts: 6,523

    seb fontana
    Member
    from ct

    Maybe the inside threaded bar is bottoming out on the plug before it can get a grip because the block is thinner at that particular hole. Maybe could put little bends near the ends of the bars to make up for lack of material..
     
  10. Any style plug can come out. Mopar racers be it drag or nascar would drill and tap the block for a strap across the plug. A high hp engine will flex allowing the plugs to fall out. Ask me how I know.
     
    Dog_Patch, shaunez and Desoto291Hemi like this.
  11. Hombre
    Joined: Aug 22, 2008
    Posts: 1,030

    Hombre
    ALLIANCE MEMBER

    Tommy, No not a 440 that is a 354 Early Hemi.
     
  12. Sorry Hombre,
    The best I could see the pic threw me off.
    I saw the reinforcement ribs on the side and immediately thought 440,,,,sorry .
    I should know better ,,,LoL.

    Tommy
     
    Hombre likes this.
  13. Hombre
    Joined: Aug 22, 2008
    Posts: 1,030

    Hombre
    ALLIANCE MEMBER

    Hey Tommy, Nothing to be sorry about, I would just bet you remember that though.
     
    Desoto291Hemi likes this.
  14. For what its worth I never use steel plugs........nice non rusting brass plugs last forever........andyd
     
    town sedan likes this.
  15. JOECOOL
    Joined: Jan 13, 2004
    Posts: 2,757

    JOECOOL
    Member

    In my corvair we call them block strenghteners.
     
    seb fontana and town sedan like this.
  16. SEAAIRE354
    Joined: Sep 7, 2015
    Posts: 181

    SEAAIRE354
    Member

    This is a very good point but I would think that the thickness of the block wouldn’t allow for that. Is there a shoulder on the bolt that may possibly be bottoming out? It seems that the torque that’s needed to lock the plug is. Properly would be much less than the effort to turn the tap inside the block. Did you try the never seize as mentioned earlier? There’s been other treads with people using these with no problems.


    Sent from my iPhone using H.A.M.B.
     
  17. The purpose of the holes is to hold the water jacket sand core in position during the casting process. In a perfect world they would not be there. They serve no good purpose in a running engine. Radiator caps vent steam pressure, when water freezes in an engine, it expands everywhere and cracks the iron. The plugs serve no purpose there either.

    Other manufacturers machine the holes with long sides so a welch plug can be 'glued' in securely. Chrysler machined shallow grooves with a landing so a cupped shaped disk sits in the pocket. the idea is to then hammer the cup flat, expanding the OD and forcing an interference it seal. It worked the beginning but over time I guess the machined rim of the hole gets enlarged and the disks no longer fit. That happened to my 331 rebuild and the disk blew out twice. The replacement plugs I used in the post above is made in two cupped pieces of copper with a thru bolt. Then the unit is placed in the hole in the block and the bolt is cinched down, the two copper cups expand a lot and give a strong mechanical seal. Add a film of gasket sealer for a good seal.
     
    Last edited: Mar 2, 2020
    gimpyshotrods likes this.
  18. shaunez
    Joined: Dec 6, 2006
    Posts: 22

    shaunez
    Member

    Thanks for all the advice guys, I used to have the brass/copper other plug that Hot Heads offered but it had a small drip of antifreeze all from after firing up the motor for the first few times (I purchased the motor from another person who stated it was built by an out of state shop, these were already in it) I tried to replaced it myself with the exact part from a nearby Advance Auto parts but it did not expand to seal in the block so I lost my patience & bought these O ringed ones.
    The motor is in a jammed tight in 1930 model A roadster and I really want to avoid engine removal for now, the frame is real close to the hole so the ball hammer can’t make it in there for discs..
    So here in the end is what I did, it seated good & tight now, adding fluid now & fingers crossed! It’s gotta drive to Cleveland Piston Power show in 10 days or bust!!
     

    Attached Files:

    Hombre likes this.
  19. Hombre
    Joined: Aug 22, 2008
    Posts: 1,030

    Hombre
    ALLIANCE MEMBER

    shaunez, Man not a damn thing wrong with that. The idea is to get the set screw tight, looks like that ought to work just fine. I am not going to go back and read all of the post on this thread but if I remember correctly I think someone mentioned something like this might work.

    Good luck at the show, don't worry about it it's a Hemi it will do just fine!
     
    shaunez likes this.
  20. " The motor is in a jammed tight in 1930 model A roadster and I really want to avoid engine removal for now, the frame is real close to the hole so the ball hammer can’t make it in there for discs.." I wrote a chapter in that book!!! This is just one small inconvenience for the distinct privilege of owning the best engine ever made by man.
     
    Hombre and shaunez like this.
  21. saltflats
    Joined: Aug 14, 2007
    Posts: 10,182

    saltflats
    Member
    from Missouri

    If it seals with a O ring, how tight does it have to be?
     
  22. Don't forget Murphy. He says, "Tighten the bolts or they will leak.". Guaranteed!
    Admiral 'Shallow Water' Murphy
     
    Hombre likes this.
  23. shaunez
    Joined: Dec 6, 2006
    Posts: 22

    shaunez
    Member

    Yeah, well I put it in last night & its leaking already..so many set backs on this build..
    I think in my haste I put the inside beveled edge on that "T piece" in wrong.. if you look closely it can be turned around. Ill try that tonight after getting baptized in coolant once again
     
  24. shaunez
    Joined: Dec 6, 2006
    Posts: 22

    shaunez
    Member

    Under the internals were covered with glyptal by the previous owener, as was but it appeared as some may have seeped into other areas because the previous leaky plug here had glyptal bonded behind it
     
  25. shaunez
    Joined: Dec 6, 2006
    Posts: 22

    shaunez
    Member

    I think upon closer inspection I might have the inner piece on backwards, I believed the beveled area was to allow for block thickness, maybe I am the reason none of this is working! GGRRRR!
     
  26. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 5,076

    Ebbsspeed
    ALLIANCE MEMBER

    Good idea welding that bar on the end of the "T". I can see these being a real bitch to remove down the road after things corrode a bit and that allen head bolt attaches itself to the T-bar.
     
  27. Ain't hot roddin' fun?!
     
    shaunez and Hombre like this.
  28. SEAAIRE354
    Joined: Sep 7, 2015
    Posts: 181

    SEAAIRE354
    Member

    Yeah but it’s worth it in the end.


    Sent from my iPad using The H.A.M.B. mobile app
     
    shaunez and Hombre like this.
  29. shaunez
    Joined: Dec 6, 2006
    Posts: 22

    shaunez
    Member

    A401D975-69B2-4BAC-ACCA-8C148B65CB18.jpeg I said a prayer, threw some holy water on it & removed the plug.
    Yup, I Turned around the “T” on the back & pressurized the system & I am leak free (fingers crossed!)

    So if anybody ever searches this in the future, look at this picture.
    If you look to the far right this is how they came in a flat sealed package without room to move around, and assembled... so that is how I put them in.. but due to the counter sink on the block, or just the center hole on MY 392 block it didn’t seal.
     
    town sedan likes this.
  30. shaunez
    Joined: Dec 6, 2006
    Posts: 22

    shaunez
    Member

    The good thing is all the pieces are stainless steel, even the part we welded on too.
    There is a large O ring on the plug, but also a very small O ring on the Allen head set screw and a recessed area in the plug body for it, it looks very professional
     
    SEAAIRE354 likes this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.