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Technical flywheel bolts 241 Baby Hemi

Discussion in 'Traditional Hot Rods' started by RobertDip, Mar 7, 2018.

  1. RobertDip
    Joined: Mar 1, 2011
    Posts: 69

    RobertDip
    Member
    from Candiac

    Have NOS flywheel bolts ( qty. 8 ) and the originals are held with nuts. Question: Are these nuts secured with a lock washer or not. I purchase Grd 8 nuts ( 7/16 UNF ) and to tighten these is not easy since there is very little space behind the crank flange. Not even a box end wrench fits....can only use the open end. Also, with the aluminum plate spacer I can only get a small turn. Does one use 'Loctite' and tighten as much as possible with an open end. ( No the crank is not drilled and threaded for a 1/2" UNF bolt......just using the existing stock set-up ) Would appreciate some help here.
     
  2. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 8,452

    Rusty O'Toole
    Member

    They did not use lock washers or anything else. Loctite would give extra security but not necessary.
     
  3. LOU WELLS
    Joined: Jan 24, 2010
    Posts: 833

    LOU WELLS
    ALLIANCE MEMBER
    from IDAHO

    Flat brass washers and correct torque worked on mine...They are a pain in the tail to work on...
     
  4. Hombre
    Joined: Aug 22, 2008
    Posts: 553

    Hombre
    ALLIANCE MEMBER

    I think the question why have you not taped the crank? The way this was designed is a huge pain in the butt, and it is so easy to tape the crank. Why go thru the pain?
     
    56don likes this.
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  5. RobertDip
    Joined: Mar 1, 2011
    Posts: 69

    RobertDip
    Member
    from Candiac

    To tap the holes is one thing, but that means the flywheel will also have to be machined to clear a standard hex bolt head. Yes, it is a pain, but it is what it is.
     
    egads and Hnstray like this.
  6. Hnstray
    Joined: Aug 23, 2009
    Posts: 9,493

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    ^^^^^and the bolt holes enlarged slightly for 1/2" bolt shank clearance...

    Ray
     
  7. Hombre
    Joined: Aug 22, 2008
    Posts: 553

    Hombre
    ALLIANCE MEMBER

    Well I guess I don't understand. I have taped three Hemi cranks for the 1/2 x20 bolts, I have never had to clearance the "crank" for anything, and I certainly have never had to enlarge the bolt holes for the 1/2" shank.
     
  8. Hnstray
    Joined: Aug 23, 2009
    Posts: 9,493

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    It's not the 'crank' that requires machine work. Nor did the OP say 'crank'. It's the flywheel that needs modification if it is a Mopar oem flywheel that was originally attached by bolts and nuts to the crank flange. The oem bolts are, as I recall, about 7/16" and the flywheel flange holes, as is, will accept a 1/2" tap for threading. That requires use of 1/2" bolts as well, therefore the flywheel holes are under size for the new bolts.

    Further, the oem flywheel uses bolts that are held in place by the flywheel (captive) heads, not hex or allen head. So, with a threaded crank flange, the flywheel bolts must be able to be tightened (turned) from the bolt head side. The flywheel requires both enlarged bolt holes and clearance for the bolt heads to be turned by a wrench of some sort.

    Ray
     
    Last edited: Mar 8, 2018
  9. Hombre
    Joined: Aug 22, 2008
    Posts: 553

    Hombre
    ALLIANCE MEMBER

    You sure are right he did not say crank, so I mis-spoke there. I have done two Early Hemi's with 4 speeds thus I have had to use a flywheel. In both case's I did use the flywheel purchased from Hot Heads and it did "NOT" require any modification at all, very simple deal just tap the crank and bolt on the new flywheel. In the other case I used a TH400 and the flex plate also required no modification. Now that may be because I used an adapter and the flex plate came with the adapter.

    I believe in making this deal as simple as I possible can as I over think everything. The additional price of a flywheel that does not need to be modified is well worth the effort for me.

    I apologize to the OP as I have let this wander completely off topic from his original question.
     
  10. RobertDip
    Joined: Mar 1, 2011
    Posts: 69

    RobertDip
    Member
    from Candiac

    That is correct in saying that the original flywheel has...." Further, the oem flywheel uses bolts that are held in place by the flywheel (captive) heads, not hex or allen head "....which brings me back to my original info search on how to make sure the nuts behind the crank flange do not become loose. So far, I'm at putting a bit of blue 'Loctite' on the thread and tighten my grade 8 nuts as tight as possible using an open end wrench. PS..in days of old...some nuts were designed to be mechanically locked and not using the nylon trick. Heat & nylon is a no-no.
     
  11. Hnstray
    Joined: Aug 23, 2009
    Posts: 9,493

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    I taken apart a few of these engines and as I recall, when factory assembled, there are lock washers behind the nuts. Not the common ‘split’ lock washer, but the so-called ‘star washer’ style. And yes, they (nuts and washers) are a bitch to work with in the confined space. Even worse (or impossible) if the engine is stuck.

    I once bought a Dodge 315 hemi from a truck (including the bellhousing, flywheel and clutch assembly intact) that had been sitting for several years. Without boring you with all the details, suffice to say it was badly ‘stuck’. Eventually I got it apart, saving the crank, cam, block and heads, but not before sawzalling the rods and hole-sawing the bellhousing.

    Ray
     
    Last edited: Mar 9, 2018
  12. 73RR
    Joined: Jan 29, 2007
    Posts: 6,102

    73RR
    Member

    ...I have disassembled a few of these engines.
    If you went out and bought run-o-the-mill nuts then they will be too fat and you will find a box-end wrench difficult to use. The oem nuts are one wrench size smaller and an internal lock washer is used.
    I am convinced that at the factory the crank and flywheel/converter/fluid coupler were assembled before being installed in the block.

    .
     
  13. Andy
    Joined: Nov 17, 2002
    Posts: 4,229

    Andy
    Member

    I have used internal tooth star washers for 28 years with no problems. Do not reinvent the wheel. A friend decided to tap his crank. The holes are very close tolerance. He did not get the threads straight and ended up drilling the taped holes out and using wheel studs to replace the original studs. Huge mess.
     
  14. RobertDip
    Joined: Mar 1, 2011
    Posts: 69

    RobertDip
    Member
    from Candiac

    I also believe that the star lock washers are the way to go. Good advice, Thanks. My engine was stuck initially and I used a thin grinding disc to cut through the heavy thick cast iron fluid drive bellhousing into pieces. Lots of fun..
     
    czuch likes this.

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