I am building a 32 B trans to go on a Model A motor. I have a couple of questions. Will a 4 cylinder 32B upper flywheel cover bolt directly to an A block? Will a B oil pan with the lower flywheel cover bolt to an A block? Do I have to use an A oil pan & make a lower flywheel cover?
The B pan will not bolt up to an A block, the main cap area is not the same and there are no pan bolts at the rear cap on the B pan to fit your A rear main. You could cut the flywheel cover off the B pan and with a little sheet metal work, weld it to the A pan and add holes and plugs to get to the A pan bolts by the rear main, use the B upper Flywheel cover and the B trans, fit Late model helical gears with syncros...... OR just get a flathead V-8 trans adapter like I did.
I do not have any other photos but this is a B trans bolted to an A block. The B upper flywheel housing bolts right on. I used a A oil pan. I then used a B oil pan flywheel cover that someone had removed and saved. I did not weld the B flywheel cover to the A pan, just bolted it up. I did use a cork gasket between the two to seal the gap. Been that way for three years now with no problems.
My RPU has a B transmission mated to an A block by using the Model B flywheel housing and Model B pan adapted to fit the A block. The flywheel housing is a bolt on, but the B pan requires modifications to fit the A block. I elected to weld a strip into the rear main area of the B pan to fit the gasket strip on the rear main cap of the Model A. I also drilled and tapped the Model A pan rail to fit the location of the bolts in the B pan. The unused bolt holes in the rear bulkhead of the A block need to be plugged to prevent oil from leaking into the flywheel housing from the crankcase. The Model A motor mounts will not bolt up to the B flywheel housing so you have to either fabricate rear mounts or find a set of the Float-a-Motor mounts that were made to install a B motor in an A frame. These mounts have been out of production for a while, but I believe Bert's in Denver has the patterns. You could check with them to see if they have plans for making any additional sets. A stock Model A flywheel also will not fit in a Model B bellhousing regardless of which pan you use, so you need to have the OD of your Model A flywheel turned down as part of the conversion process. Follow any of the diagrams that show how to reduce the weight of a Model A flywheel by cutting down the outside diameter of the A flywheel. The third photo shows my cut down A flywheel. Finally, if you go with a B pan or a Model A pan with a B rear added to it, you need to remember to install the flywheel before the oil pan. It will not fit into the opening if the pan is installed first (ask me how I know). Good luck!
brjnelson /62pan / 5280A2 --- Thanks guys for all the information and the pictures. I think I am on track for this part of the project. The B trans will have a late set of open drive gear. I will use a lightened A or B flywheel (35-37#) with a 9" clutch/pp.
fordcragar -- I am in the purchase stage and will post pictures when I start building. Still trying to get my ducks in a row.
rexrogers --- Trying to use all pre 53 parts and OEM stuff. Second is that it will cost about the same money to build a nice 39 trans as I will spend building a 32 B case trans with late gears, then I have to fork out $450 for an adapter. This may not be for everyone but I think it will fit into TROG group.
Is the B transmission worth all that effort over the A? I guess if I had a B trans and not an A trans....
My answer is yes - the synchros make driving a lot easier without having to double clutch with every gear change. A modified four banger is not something you want to lug, so I do a lot more downshifting with the modified car than with my stock A.
The Jalopy Journal
