converting BBC to a hemi

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by CjRedden, Jun 29, 2017.

  1. CjRedden

    CjRedden Member

    Joined:
    Jan 16, 2010
    Messages:
    149
    Likes Received:
    0
    Hey guys,
    I am looking to get rid of my big block chevy and make the move to a hemi. can anyone give me some insight as far as fabrication I will need to do. I already know I will need new headers and change around the fuel cell a little bit in front for room with a new fuel pump to make it more manageable. I already have a Chevrolet bellhousing for my lenco drive. (my bellhousing is open at the bottom, not fully enclosed) since I run top sportsman. do I need to switch to a fully enclosed bellhousing? or should I?

    is there such a thing as having my motor plates and bellhousing machined to match a hemi? if I don't have to buy new motor plates and midplates I would be much happier having them switched over. can they redrill a bellhousing to match and still have the starter pocket lined up?

    I would like to have this all mocked up since I can get ahold of a block and heads that are junk just for a mockup.

    any help and input is greatly appreciated.
    thank you
     
    #1
  2. turbo69camaro

    turbo69camaro Member

    Joined:
    Nov 26, 2007
    Messages:
    228
    Likes Received:
    6
    With hemi motor chevy bell you will have to run the .500 thick mid plate with flat head screws for motor and special studs for bell .front motor location will be different so building a new front plate and mounts and tabs will be needed. Also make sure you have room for the hemi oil pump
     
    #2
  3. Mike Canter

    Mike Canter Top Dragster

    Joined:
    Mar 10, 2004
    Messages:
    4,081
    Likes Received:
    64
    A. Heavy bolt pattern on the bellhousing will not match up with a hemi unless the bellhousing has a dual bolt pattern. Call Jeff Bohr ((734) 454-4475, who makes a great bellhousing and talk to him. He can guide you.
     
    #3
  4. TADHemiracer

    TADHemiracer Member

    Joined:
    Dec 9, 2010
    Messages:
    346
    Likes Received:
    13
    I did the same thing years ago. Coan makes an adapter plate that fits on a hemi block and bolt pattern for chevy bellhousing and has the starter pocket located to work with the chevy ring gear. I now have a hemi pattern bellhousing. PM me if you are interested in the used adapter plate.
     
    #4
  5. Mike Canter

    Mike Canter Top Dragster

    Joined:
    Mar 10, 2004
    Messages:
    4,081
    Likes Received:
    64
    You need to make sure your bell housing complies with SFI 6.3.
    Also if you use a spacer that moves it back you need to make sure it still complies
    August 15, 2012 - SFI Specifications 6.1, 6.2, and 6.3 for Bellhousings have been revised. Bellhousingsthat utilize liners must have the liner(s) installed so that they are flush with the flange/mounting surface of the bellhousing. Paragraph 16.0 of each Spec requires new products to comply with the revision within 90 days of the effective date (August 15, 2012). Therefore, newly manufactured bellhousings must comply with this requirement as of November 15, 2012. Existing bellhousings in the field may continue to be used and must be brought into compliance upon their next scheduled inspection and recertification by the manufacturer.
     
    #5
  6. WIDEOPEN231

    WIDEOPEN231 Member

    Joined:
    Jun 10, 2011
    Messages:
    44
    Likes Received:
    5
    New bell housing would beat adapter 10 to 1 IMO. Just so much simpler and stronger setup
     
    #6
    Will Hanna likes this.
  7. Dale H.

    Dale H. Member

    Joined:
    Dec 7, 2005
    Messages:
    296
    Likes Received:
    5
    Just go to a Miner Bros.Hemi.Its the best of both worlds. It already has dual pattern (chev&chrysler) on the back, and chev mounts on the front.Plus it is the most easily serviced motor out there by far!
    -Dale
     
    #7
  8. Dale H.

    Dale H. Member

    Joined:
    Dec 7, 2005
    Messages:
    296
    Likes Received:
    5
    Another thing when switching from a Chev to Chrysler is the upright tube in the frame is sometimes in the way where the Chrysler hemi oil pump sticks out. (If you have a funny car or dragster chassis)
    -Dale
     
    #8
  9. CjRedden

    CjRedden Member

    Joined:
    Jan 16, 2010
    Messages:
    149
    Likes Received:
    0
    Thank you guys. This is in a top sportsman 1970 nova. 25.2 chassis. My concerns with a miner bros hemi is availability of parts.
     
    #9
  10. jody stroud

    jody stroud ZOMBIE Top Dragster

    Joined:
    Sep 3, 2007
    Messages:
    843
    Likes Received:
    10
    Don't worry about spare , carry a couple of pistons and rods,
    Be about all the spare parts you'll ever need. Rod. Earnings are same as regular hemi Main bearings are cheap to keep a spare set in trailer and they last a long time. You have to try pretty hard to hurt a MBR hemi. Run the timing Bob tells you to, keep the tuneup on the fat side and let
    It eat.
     
    #10

Share This Page