1930 Model A, but 1932 B Engine

1930Ford

1930Ford

Junior Member
My understanding is that my 1930 2-window Model A (see photo), has a B Engine.

Please explain.
 
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First thing, a B head has a 3 bolt water pump. A B block has a fuel pump"hole" in the block, usually covered with a plate in an A. Lots of other differences, those are easy to spot from the back of a galloping horse.
 
A lot of updates came with the model B engine. A good part of it was to get 50-horse power from an older type design. The rest of it was a more modern 3-speed semi-synchronized transmission that changed the oil pan and the flywheel cover/bell housing. The model B engine takes modifications in order to install it in the model A. Model B engines serial numbers were stamped on the flywheel housing so the pad near the coolant inlet elbow had no number originally unlike the model A engine block.
 
The Model "B" engine (Circa 1932 - 1934 & aftermarket thru 1941) is far superior to the Model "A" engine. If your car has one and you will be doing a lot of touring, keep the "B" engine. Relative to the Model "A's" engine, the Model "B"engine has:
>Pressurized oil system to main bearings and camshaft bearings;
>Improved camshaft for better breathing;
>"B" cylinder head has slightly higher compression ratio, and a Model "A" head fits;
>Larger main and connecting rod bearings.
 
And if you get a late 32 and up it has a counterbalanced crankshaft. Most post production engines have hardened exhaust valve seats.. the later B’s also can have a high lift cam,up to .340 actual lift, all B cams have a better profile than the A. The crankshaft has substantially larger journals (2”). The cam and main bearing receive positive flow from the oil pump, it is not a pressurized engine. All in the the “new and improved” 4 cylinder for 32 was a success except for one issue.. it’s far more prone to crackinggenerally from the exhaust valve seat to cylinder on 2 and 3 … which can be repaired by pinning, hard seats and sleeves.
 
Correct me if I'm wrong, but I seem to remember that the B exhaust manifold has a different slope at the back.
 
That manifold is correct for the 1932 model year. In 1933/34 the manifold is almost identical to the model A.
 
I would like to clarify some terminology.

The 1930-31 Model A high compression head (5.2 to 1) (A-6050-B) has a large B cast into it. This head uses a 4 bolt Model A water pump. Frequently call a "B" head.

The 1932 to 34(?) 4 cylinder block with oil pressure to the mains and a fuel pump mounting on the intake and exhaust side. Frequently called a "B" engine. It used a 5 to 1 compression head with a large C cast in it and a 3 bolt water pump.
 

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Also, the B engine has a different distributor with an automatic advance and a different carburetor and intake manifold. Below is a photo of a 1932 B engine. Your B engine may have a Model A exhaust manifold and a Model A distributor and maybe a Model A head.


489149
 

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Be aware that the front timing gear cover is different on the Model B which can result in the timing not being set correctly if a Model A distributor is used.
 
14 degree advance at the normal timing of a model a by using the pin in the timing gear on a B, that's what those centrifugal advance dizzys want for base timing. Model A the timing gear pin drops at 0 degrees.

I am running a B motor myself now, the extra power is very nice. Keep running it and enjoy. The only thing better than a B motor is a Burtz Block at this point for power and strength. A good touring motor is 75 HP and up with good gearing, it will pull hills in 3rd all day. Fun to drive and will outrun your buddies.
 
Mechanically they are superior but a lot of them are cracked, some visibly, some hidden. Cracks are even more of an issue with B blocks than A blocks.
 
chrs1961815 said:
Mechanically they are superior but a lot of them are cracked, some visibly, some hidden. Cracks are even more of an issue with B blocks than A blocks.
Click to expand...

Unfortunatey, from what I've heard this is true. However, all is not lost! There is a marketer the "B" parts such as the cam, crank, the head, distributor, carb and manifold, flywheel. So when your"B" block cracks almost all of the more refined "B" parts will fit and provide the same advantages as they did in the original "B" engine.
Good Luck! Terry
 
This Diamond B block has been pinned, sleeved and exhaust seats installed. All quality work and in my experience a crack relieves stress, I am going to build it.
 

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One other thing not mentioned is that the B engine does not have the outside oil return pipe, but a larger valve cover plate with the return line built in.
 
midgetracer said:
One other thing not mentioned is that the B engine does not have the outside oil return pipe, but a larger valve cover plate with the return line built in.
Click to expand...

The B engine has no internal return line, only a pressurized feed line to the mains and camshaft. The B-engine has oil return via drillings in the valve chamber floor that allow oil to drain into the dipper tray, something Ford should have utilized for the Model A.
 
You can’t drain the valve chamber floor to the dipper tray on an A, you will starve the main bearings and cam bore.

The stock B oil system is not pressurized, it works on flow.
 
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