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Hot Rods Putting together unrelated clutch and engine

Discussion in 'The Hokey Ass Message Board' started by Deere boy, Aug 1, 2023.

  1. Deere boy
    Joined: Jul 25, 2018
    Posts: 74

    Deere boy

    Has anyone ever built their own adapter to mate together an unrelated engine and clutch housing? I've never tried this, but might need to for a project I have in mind. They are roughly the same size but don't exactly match up. Looking for general advice. Don't tell me not to do it because that will just make me want to try it more.
  2. hrm2k
    Joined: Oct 2, 2007
    Posts: 4,800


    What kind of transmission ?
    What kind of engine ?
    In my V8 Corvair, I connected a small block Chevy to a Cadillac transaxle. I got a BOP To SBC Adapter from Jegs.
    You might check with Jegs or summit. They both carry Transdapt . I think they have most combinations covered
    Good luck
    rod1 likes this.
  3. Deere boy
    Joined: Jul 25, 2018
    Posts: 74

    Deere boy

    Okay, I'll probably get bounced off here for this since it's not car related but I figure that you guys would be the ones who have done it. I'm trying to build a half-scale working model of a famous tractor. The engine is a small four-cylinder flat head, same as in an IH Cub. I can't use the original Cub clutch housing because it has a long torque tube that goes back to the transmission and that won't work for this build. I haven't settled on a clutch yet, but there are quite a few that are about the same size.
    2Blue2 and hrm2k like this.
  4. SEAAIRE354
    Joined: Sep 7, 2015
    Posts: 535


  5. Deere boy
    Joined: Jul 25, 2018
    Posts: 74

    Deere boy

    Last edited: Aug 1, 2023
  6. Budget36
    Joined: Nov 29, 2014
    Posts: 13,035


    Can you shorten the torque tube?
  7. Deere boy
    Joined: Jul 25, 2018
    Posts: 74

    Deere boy

    That is another way it could go.
  8. TCTND
    Joined: Dec 27, 2019
    Posts: 519


    This has been done many times in the past with varying degrees of success. The key to a good outcome is precision. The axes must line up precisely and the faces must be square. It's not really a job for a hand drill and hacksaw.
  9. Jmountainjr
    Joined: Dec 29, 2006
    Posts: 1,646


    The most important aspect of such a project is keeping the transmission input and crankshaft center aligned correctly. Get the adapter rough shaped and get the center hole concentric to the crank and then pin the two before drilling engine bolt holes.
  10. Duncan71
    Joined: Jan 17, 2022
    Posts: 54


    Could be really simple with some cad skills. Or be straight forward with a grinder and torch and punch & drill! Got and pics of the mating surfaces?
  11. AccurateMike
    Joined: Sep 14, 2020
    Posts: 612


    Deere Boy, I'm fooling with one now. There are a few things you have to get together before you get to the bolt patterns.
    Pilot bearing: Mine originally had a bronze bush. The new trans uses a bearing. I was able to machine the bush's ID for the bearing.
    Input shaft splines: You need to find a clutch disc that has the same sort of hub (so springs don't foul stuff) and spline size and count. My original was 10T, new 23T. The disc that fit the new trans was 1" bigger than my flywheel and the hub fouled the flywheel. I had to buy a few likely candidates and try them out. Rock Auto is a great resource to use to find stuff like this. Pictures and dimensions. I found one that fit the flywheel and splines.
    Pressure plate: I had a kind of narrow band for my pressure plate bolts to land on. The new trans' was 1" to big. I needed to find one with fingers the same height as the new trans' were and a diameter that I could drill on my flywheel. Again, pictures in Rock Auto. I bought some stuff I will never use, just to try. Discs were all the same thickness (~5/16"). I don't know if that is a thing.
    Flywheel: My original is a "cup", the new needed to be flat (or nearly). I machined the cup off. Lost 3-4 LB while I was at it. The new pressure plate was in an application with a " +.020" " flywheel. The friction surface is .020" proud of the bolt surface. I machined that and drilled & doweled the flywheel for the new pressure plate.
    Throw out bearing: Depending on the relationship of the fingers and bearing, length of the input shaft and depth of the bell you may need to come up with something to fit. My engine has about 1/2 of an integral bell on the back of the block. The new trans has a full bell. Luckily, I can save the throw out arm and shaft part of my trans when I cut the bell. I figured where to cut the bell by finger to T/O contact point.
    That's where I'm at now. I am going to make a plate that bolts onto the back of the block. Cut a hole in it that the (cut off) bell fits into. I'll line it up as best as I can and leave some wiggle room between the bell and plate. If I have the bell sit on the plate, I have to be dead nuts, first try. Then, I'll offer up the trans, jiggle and align and shim until I'm happy ( probably 2-3 days ). Tack and test, I guess. BTW, my bell and plate are aluminum.
    Good luck ! It's fun ;) Mike
    2Blue2 likes this.
  12. '51 Norm
    Joined: Dec 6, 2010
    Posts: 824

    '51 Norm
    from colorado

    There are several videos on youtube where people are adapting various engine/clutch/transmission to each other. I doubt that any of them are exactly the same as what you are doing but the methodology will be the same.
  13. Gotta have CAD and something better than a drill press to pull it off. Make "test" pieces from wood or something else disposable before cutting metals up. Model up the 2 parts you wish to join, build the adapter around those. Just my 2¢.
    gimpyshotrods likes this.
  14. FrozenMerc
    Joined: Sep 4, 2009
    Posts: 3,087


    For years I ran my '51 Ford F1 with the following setup. Never had a bit of problem until teeth came off of the 1st gear cluster doing a burnout.

    Engine: 1978 351W
    Transmission: 1965 BW 3 spd + OD
    Bellhousing: 1982 F250 Windsor to 4 spd. redrilled to the 3 spd pattern.
    Clutch Pressure Plate: 1982 F250
    Clutch Disc: 1970's Dodge Pickup - needed to fit the 26 spline input shaft on the 3 spd and the larger 11" truck clutch.

    The hardest part is ensuring that the trans input shaft is concentric and colinear with the engines crankshaft, and that the depth of the bellhousing is right for the pilot bearing / throw out bearing / torque convertor /etc being used. This requires a way to precisely measure bolt patterns and calculate pin centers. It can be done with straight edges, calipers, and a bit of old fashioned geometry. Beyond that, it is basic machining and fabrication. You don't need CAD, but it helps. Remember the Boeing 747 was designed and built long before CAD was even a twinkle in some computer programmers eye.
    Last edited: Aug 2, 2023
    rod1 and 2Blue2 like this.
  15. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 5,091

    from illinois

    Depends on how good you are with a hand drill & hacksaw , a file would help , keep in mind people built watches with hand tools ! Most auto related stuff is crude , comparatively !
    bobss396 likes this.
  16. I had a buddy at work... machine shop 2nd shift on CNC mills. He could make anything I drew up, tough jobs, give him the DXF file and let him loose. I usually had what I needed on my desk when I came in the next morning.
  17. bobbytnm
    Joined: Dec 16, 2008
    Posts: 1,662


    I'm in the process
    So far I've mated a 1954 Packard 327 straight 8 to a 1984 GMC T5 5speed. I built the adapter and am using the Packard flywheel, GM large bellhousing and diaphragm style clutch. Its all bolted together but as yet is untested.
    I'm in the process of dialing in clutch linkage but life has been crazy and I haven't touch it in 6 months or so.
    There are some pics of it here;
  18. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,211


    I have a GM T56 connected to a Falcon-6, via a modified stock flywheel, and a Mercedes clutch (Kevlar SPEC Stage II+).

    I made the adapter to attach to a first-gen Econoline bellhousing.
  19. shorrock
    Joined: Oct 23, 2020
    Posts: 135


    Connected french flathead to french (rare) aluminum bellhousing and with homemade adapterplate to a SSang Yong transmission (T5 copy). Used the SSangYong clutch and redrilled the flywheel. As the outputshaft has different splines than the US transmissions I found a japanese yoke that fits the korean box. There is always a way to make it work
  20. nickleone
    Joined: Jun 14, 2007
    Posts: 463


    Watch this:
    Many more youtube videos like it
    rod1 likes this.

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