model B motor in model A chassis

I kept the Model A transmission. This saved me worrying about pedal adapters and wishbone adapters. I have never had problems shifting the Model A transmission. My first car was a Model A and no it was not new. The Model A flywheel housing will bolt directly to the Model B block. The rear motor mounts attach to the flywheel housing. The Model A front motor mounts bolt directly to the front of the Model B engine thus that problem is solved. I prefer the original mounts to the float-a-motors but that may just be me. The one thing you are going to have to do when you make the conversion is to cut off the back of the Model B oil pan (see photo). If you are lucky you might be able to swap for a pan that has already been cut. The whole project was extremely easy.

Be sure your Model B motor is from 1932. A Model B motor from 1933 or 34 is shorter to allow for the sloped grill. The water pump is shorter (see photo, note the spacing of the grease fittings). The generator is further back on the timing cover (see picture) and the front pulley is shorter (no picture)

Charlie Stephens
 

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The previous caretaker made these modifications. I don't know who made the adapters, but this will show what was done .
 

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So Charlie Stephens, are you saying if I have a 1933 motor it won't work in an A chassis?

I believe the water pump is the longer one.

Maybe best to check serial number, if I can make it out.
I was told it was a 32, and wasn't aware of the differences. Thanks for your help!
 
I have a 34 B engine in my Cabriolet. I just put a higher compression head on it that uses a model A water pump. I've never heard of the actual block being different length. Different length water pumps but not the engine block. Also, I've never seen a serial number on a B block.
 
My "Diamond B" block was cast (D126 left side of engine) April 12, 1936. Like foxfire42, it has a Brumfield A head and an A water pump. The serial number is on the bell housing and starts with BB. This number was accepted by the CHP and DMV. I happily didn't have to lift the body.
 
So Charlie Stephens, are you saying if I have a 1933 motor it won't work in an A chassis?

I believe the water pump is the longer one.

Maybe best to check serial number, if I can make it out.
I was told it was a 32, and wasn't aware of the differences. Thanks for your help!
The '33-'34 blocks are the same as the '32. What I am saying is if you have the water pump, timing gear cover and crank pulley from a '33-'34 engine you should plan on replacing them with the ones from a '32 (or a Model A). The water pump is the shorter one in the picture. There shouldn't be a serial number on the engine as they were numbered on the flywheel housing beginning in 1932. The pad was there for the number but it was blank.

Charlie Stephens
 
The engine number on a B engine is not on the pad on the side of the block. It is on a pad on the flywheel housing just above the starter. To use an A gearbox on a B engine, the flywheel housing is changed for one from an A engine and the sheet metal part of the housing removed from the back of the sump. The B number is lost. All that is left is the blank pad on the engine. That might cause some head scratching when it comes time to register a car with such a set up in it.
 
Wow, good information here, thanks for the input. The engine looks complete other than carb. oil cap and I'm guessing fuel pump. Are these fuel pumps and oil caps available?
 
Wow, good information here, thanks for the input. The engine looks complete other than carb. oil cap and I'm guessing fuel pump. Are these fuel pumps and oil caps available?
Fuel pumps are available but expensive (a couple of hundred for a rebuilt one). Why do you need a fuel pump with an installation in a Model A, just use a block off plate which you can make or buy? This assumes you are not running down draft carbs. Very early engines used the Model A oil cap but the later larger ones you need to look for but they are available. A lot of the Model B engine parts are available from the Model A suppliers but rennerscorner.com, (734) 428-8424 is probably the best place for Model B parts.

Charlie Stephens
 
I should have posted earlier that the Model A oil filler tube and cap can be used on the Model B engine. The Model B tubes were at first longer (very early) and later a larger diameter . This was done to reduce oil being blown out of the tube, a problem that shouldn't exist on a well built engine.

Charlie Stephens
 
If you put the B motor in the A and use the Model A Bellhousing and transmission you must trim the back of the B pan in order to fit.this is what I did on mine---B motor runs very smooth.
 
How did you trim back of oil pan off? Did you take seam loose where back of pan is tacked. I see the rear seal is larger on B motor.
 
So Charlie Stephens, are you saying if I have a 1933 motor it won't work in an A chassis?

I believe the water pump is the longer one.

Maybe best to check serial number, if I can make it out.
I was told it was a 32, and wasn't aware of the differences. Thanks for your help!

The factory didn't put numbers on B engines.
 
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