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Technical Need some help with Av8 conversion

Discussion in 'Traditional Hot Rods' started by project starter, Apr 8, 2018.

  1. im building my 31 roadster and seem to run into an issue. The car was an abandoned project and I’m not sure exactly what parts were used to start the project. I have a stock frame with a Tardel 32 k member,39 trans, 50 flathead and a closed banjo rear. The torque tube seems to be too short by about 2 inches when I try to install the motor and trans into the crossmember. Do I need to move the rear forward of the rear spring? Do I have the wrong rear and torque tube? Thank you for any help with this.
  2. Pictures...Might need another t-tube,what rear is there?How is the engine mounted?
  3. If you post your city on your profile,maybe one of your neighbors would help you..
    Why do newbies do this kind of crap???unless you are in the "witness protection" program..
  4. Pics would help as stated above.
    Not sure posting your city will help.

    Sent from my iPhone using H.A.M.B.

  5. Model A Gomez
    Joined: Aug 26, 2006
    Posts: 1,321

    Model A Gomez

    This is the problem with someone else's project you spend a lot of time fixing problems they had, probably why it was an abandoned project. What rear end, most V8 rear ends had a longer torque tube and a Model A torque tube should be the right length if the engine/trans is mounted in the right place. Where is the front of the engine in relation to the front crossmember ? The angle on the picture isn't good but the water pumps clear the radiator by about 2 inches. Hard to tell what you have from your questions

    Attached Files:

    Last edited: Apr 8, 2018
  6. Those pictures really helped. I was using Verns book on traditional hot rods. Here are some pics of what I have going on. The plates in the front are temporarily holding the motor up in the frame

    Attached Files:

  7. Lazy Jake
    Joined: Feb 4, 2008
    Posts: 59

    Lazy Jake


    I hope the picture makes it with the post. A V8 rear end will have the scallops where the T-tube bolts up. The picture shows a shortened ‘41 rear end in a ‘32. The Model A rear end is going to be the weak link in your drivetrain. Also, it is very difficult to shorten an A Model driveshaft as the pinion is part of the shaft. You might want to source a V8 banjo while your in this stage of your build.

    Sent from my iPhone using The H.A.M.B. mobile app
    flatford39 likes this.
  8. alchemy
    Joined: Sep 27, 2002
    Posts: 15,779


    The early printing of the Tardel book has a mistake in the measurement of the front motor mounts. If your chassis was set up using those measurements, you might have the engine too far forward. That might be why the torque tube is too short.
    wheeldog57 likes this.
  9. I have everything bolted up and it looks like it should work. I like that the motor is back from the front cross member a few extra inches. I will have to adjust my firewall a little for clearance.
  10. The engine mount measurements in Tardels book are also based off of the earlier water pumps, crank pulley and distributor, the late engines are about 2 inches longer and require the radiator to be spaced out to accomdate the longer pumps. The crank pulley is also different and I had to machine off the front sheave to clear the front spring u-bolts. I did not have to modifiy the firewall in my pick up to clear the engine but it was sectioned to accomodate the channeling of the cab. The longer V8 torque tube/driveshaft and beefier rear should be used and the torque tube shortened to mate it all together. Pretty sure that was already mentioned above.
  11. Thanks for all the info and help. I guess I need to find a V8 rear and torque tube. I also nee to find a et of rear bones. My car is missing them.
  12. Can I ask about the front wisebone . Most case there extend or lengthen to reach the K-member but looking at the picture it looks like you mount to the bottom of the V8 transmission ?
  13. rusty valley
    Joined: Oct 25, 2014
    Posts: 1,718

    rusty valley

    you need the body on, and radiator on while doing the mock up. in most cases, you may have the body on and off 5 times before you have all measurements where they need to be. even if you only have a suburban garage, you can brace across 3 trusses and have a strong enough place to have the body hanging there so you can lift it up and down by yourself. its worth the effort
  14. e z i
    Joined: Sep 5, 2007
    Posts: 564

    e z i

    I split the wishbone on my 31, mounted them to the frame. Ya kinda have to..
  15. The wishbone mounts to the receiver cup on the cross member .
  16. Lazy Jake
    Joined: Feb 4, 2008
    Posts: 59

    Lazy Jake

    What Pocket Nick said: The 8BA (49-53)is a longer engine than the earlier flat motors. If you plan to run a hood, you will be very challenged to fit everything between the firewall and the radiator. It can be done but, it will be tight. Do you have Ron Bishop’s/Vern Tardels book on building an A-V8 roadster?

    Sent from my iPad using The H.A.M.B. mobile app
  17. If you can find a '32 wishbone you will not need to split it, it will go right into the K-member socket if the k-member is in the right spot.
  18. dwollam
    Joined: Oct 22, 2012
    Posts: 1,089


    My '29 AV8 has a Model A rear end that has been in the car since 1958 and was a daily driver for about 10 years. Then as an occasional driver. Do I want a V8 rear end? Yes I do, but this one is still working, just can't get squirrely!

  19. Previous posts have touched on it; but since the wishbone and K-member locate the engine; you need to evaluate how the 8BA front works out with the fan and radiator.
  20. I do have Vern's book and hid 32 K member in my car. I believe I have the engine mounts figured out. Thank you.
  21. cederholm
    Joined: May 6, 2006
    Posts: 1,621


    Gotta follow this - I'll be in the same boat soon. Good luck, looking good!

    ~ Carl
  22. Model A Gomez
    Joined: Aug 26, 2006
    Posts: 1,321

    Model A Gomez

    Several comments, my avatar was a V8 A with a stock rear end and the coupe I'm building also has a stock rear end. The axles and bearings are the same diameter as the V8 rear end, the big difference is the ring and pinion is smaller and lighter than the V8 rear end. The weak point is the axle keys, they will usually shear before you break anything, An A rear end will hold up if you aren't too rough on it, people ran them forever. As to the firewall set back with the 8BA I had to set the bottom back about 2", set back as little as possible.

    Attached Files:

    project starter and LSR 2909 like this.
  23. Thanks for all he help and info. I took some time off from working on the car and finally got to work on it today. Got the motor and trans in and cut the firewall. Mounted the F100 steering box. I need to focus on this and finish it

    Attached Files:

  24. Fire Fox
    Joined: Aug 24, 2015
    Posts: 162

    Fire Fox

    That’s going to be killer with a blown flatty in it! I just got a late 31 Roadster and found a engine, transmission, and rear end from a 39 Ford coupe, I just got my copy of Vern’s book in and I’m ready to start the process also. Good luck and keep us posted

    Sent from my iPhone using The H.A.M.B. mobile app
  25. The book is helpful, but there are some measurements that are questionable. Vern's web site has some good parts that make building a traditional hot rod a little easier.
    Fire Fox likes this.
  26. If you are planning to run that blower, the previous comments about using the Model A rear do not apply. Also, you will have no chance of using a stock hood since the radiator will have to be mounted farther forward.
  27. Even worse than just running the blower you will have the inclination to stick your foot in it. With the blower I would get a stronger rear end. Once the rear end is strong enough you will knock out the center main on the engine, and it goes on from there. If it was me I would forget the blower and run a couple of carbs, drive it and enjoy it, but that is just me.

    Charlie Stephens
    candress87 likes this.
  28. ydopen
    Joined: Mar 14, 2010
    Posts: 200


    As mentioned you will need all components assembled before you weld engine mounts and K member in. headers and steering box plus body, pedals, and radiator. I left my mounts loose held on with C clamps for a long time as I planned stuff.
  29. dirt t
    Joined: Mar 20, 2007
    Posts: 4,664

    dirt t
    from Kingman,AZ
    1. HAMB Old Farts' Club

    In looking at your pictures the center of your rearend looks like it's forward of the center of the rear crossmember. If so your wheels will not centered in wheel opening.
  30. The rear is bolted in the stock location in the rear crossmember. The tires were centered in the wheel well when the rear fenders were on the car.

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