B-engine bell housing

Tom Endy

Well-known member
I know little about B-engines, so please excuse me for asking a basic question.

Does a B-engine use the standard A-engine bell housing?

Tom Endy
 
No,

The "B" engine uses a "Half" flywheel housing and the "B" pan has an extension at the rear that makes up the lower half of the flywheel housing. This bolt pattern will not fit the "A" bell housing but will fit the "B"" transmission case that has the bell housing as part of the transmission case.

You can bolt a "A" flywheel housing to the back of a "B" block and then remove the extension on the "B" pan. This way, you can use a "B" engine with the "A" bell housing and "A" transmission.

Chris W.
 
Chris W is on the money. I have a B engine on the bench as I type and I've just (in the last 5 minutes) fitted the flywheel housing and flywheel.
 
I would think that if you have a B engine it would be easier to use a B transmission instead of having to modify it to fit the A transmission.

David Serrano
 
no, no pedal mount or radius rod mount to match A r/rod , can all be done with modifications, been there , easier cut the rear of B sump & fit A flywheel housing , giving you engine mounts too,
 
Hi Tom,


If using a Model "B" engine in a Model "A", the Model "B" oil pan needs to be modified by cutting off its flywheel housing. A Model "A" flywheel housing will bolt to the Model "B" engine without any modification to the housing. The photos show a Model "B" engine with a Model "A" flywheel housing, clutch and transmission going into my Victoria.

An alternative to using a relatively scarce Model "B" oil pan, is that a Model "A" pan can be modified to work. Reliefs need to hammered into the sides of the "A" pan to clear the connecting rod caps. This is easily done with a ball peen hammer. Also, the semicircle cutout in the back of the "A" pan needs to be trimmed to accommodate the larger Model "B" rear main bearing. I did this for the Model "B" engine that is in my Coupe.


In the case of my Victoria, there was zero gap at the tabs of the flywheel housing to the "B" block, so no shims were used. Also, the dust cover on the Model "A" flywheel housing may just touch the modified Model "B" oil pan, but it's not an interference, just a light contact.


 

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One comment about using the "A" pan on the "B" engine.
You do not have to dimple the pan rail if you use 12pt nuts on the rods.
You will have to torque them and not use cotter pins.
McMaster Carr has them, 90759A450
ARP makes them.

John
 
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