model B motor fit on Model A transmission ?

Tom Bellfoy

Senior Member
will a 1931 model A Ford manual transmission fit directly onto a 1932 model B Ford four cylinder motor without an adaptor ?
Anything else I should be concerned with when trying to match these two up ?.
 
The short answer is yes, the bell housing has to be what was on the model a. Bell housing, clutch housing, starter housing, whichever it is called. The exhaust manifold on a B may be at a different downward angle and you also have options on using a model a timing gear cover so you can set timing as an a is set. I may be wrong on some of this but again the short answer is yes. Someone who knows more than I will chime in with definite answers. I’ll be doing the same before long so document how it goes for you if you do it and share how it went. Good luck!
 
The B oil pan has to be modified for a model A flywheel housing to be installed to the block or a model A pan has to be modified to fit to allow this. The model B pan has clearance built in for the connecting rod throw pathway.
 
Are you contemplating putting an A transmission in a Model B, or putting a Model B engine in a Model A?
 
Here are some photos of the Model "B" engine I use in my Model "A's." The 2nd photo shows the modification to the Model "B" oil pan where its flywheel housing was cutoff to accommodate the Model "A's" flywheel housing. The 3rd photo shows the Model "A" clutch housing & transmission installation (no mods to these). The last 2 photos show the Model "B" pan with its flywheel housing before it was cutoff.
 

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Here is a "B" pan that has been cutoff.

This was done the easy way, flame ax and grind off the undesired portion.
I typically use a spot weld cutter and remove the entire undesired portion.

Note, if you are running the "B" motor with stock rod nuts, make sure to use the "B" pan.
You can see the external dimples for rod nut clearance.
If you change the nuts to ARP small 12 pt nuts you can run the "A" pan, but will need open up rear seal area.

J
 

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I will be going to Hershey on Tuesday (2022) and will be looking for a Model A bell housing to replace the original B housing that came with the B motor.
For your info I have obtained a very nice rebuilt Model B 4 cylinder motor along with the syncro transmission, flywheel, clutch, the complete assembly, It also has the correct timing cover for a B motor. however the syncro needs to be overhauled.
Due to the fact that the Model B syncro trans has only one pedal attached and I hear that adaptor kits were very scarce I have just decided to use a good Model A original transmission.

Bob:
Can you describe how you had to modify the "B" oil pan to fit the "A" bell housing ?
 
There is a lot of info on here just search B engine a model Aanswer a lot of your questions you don't know about yet. I put one in a 31 pu and a lot of problems that have to be solved if you use the float a motor mounts
 
Sounds like a guy would be better off to buy a B core as a unit with the trans and engine together, and simply change them as a unit.
 
It is a simple straight forward conversion . I have a B motor in my AA truck and cabriolet . Dont try to convert the A pan too much hassle cutting a bigger "U" at the back etc etc . The B pan shroud can be welded on or spot welded just cut it off with a cutting wheel taking care not to cut the pan itself . The A flywheel housing bolts up to the B block same pattern .

John in sunny morning Ian here soon Suffolk County England .
 
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