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BBC Rear Seal in BBF Block?

4587 Views 9 Replies 4 Participants Last post by  J. Shelfo
Jon,

I purchased a crankshaft from Bryant that is drilled for both BBC and BBF flywheel patterns. The problem with this is the journal that the seal rides against is reduced to BBC size. My understanding from Bryant is that this is fairly standard these days. My question is how do you install the BBC rear seal in a BBF block? Do you offer an adapter for this sort of thing? I'm running a cast iron Eliminator block.
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Jon,

I purchased a crankshaft from Bryant that is drilled for both BBC and BBF flywheel patterns. The problem with this is the journal that the seal rides against is reduced to BBC size. My understanding from Bryant is that this is fairly standard these days. My question is how do you install the BBC rear seal in a BBF block? Do you offer an adapter for this sort of thing? I'm running a cast iron Eliminator block.
I have'nt heard of this before. Trying to figure what advantage it would be. To modify or adapt a rear main cap seems like work for no net gain.
heard of bbc rod journals, but never the rear main seal. can you post a pic of this ? i have to see this
BBC Rear Seal

If you go to Kaase's website, look at the picture of a Bryant Crankshaft. Look closely at the rear journal on the crankshaft. You will notice that the rear journal is turned smaller in the area where the rear seal rides. Normally, this is slightly larger than the 3" main journal, approx 3.140".
If you go to Kaase's website, look at the picture of a Bryant Crankshaft. Look closely at the rear journal on the crankshaft. You will notice that the rear journal is turned smaller in the area where the rear seal rides. Normally, this is slightly larger than the 3" main journal, approx 3.140".
Looked at the pic. It may be because of the dual Chev./Ford flywheel bolt pattern. I believe the Chev. pattern is a smaller diameter.
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BBC Rear Seal

It (BBC) is definitely a smaller bolt pattern. I assume they are doing this to run a smaller (8") clutch. I'll try and attach some photos of what I machined up this morning. The only reason this could work the way I did it, is that the BBC seal has a thinner flange on the front side. I am concerned about moving the seal this far forward, as it does not have much clearance between the front of the seal and the flange (oil slinger) on the crank. What do you think?

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Looks like a good job to me. The lip is just off the radius and should work o.k. as long as the thrust clearance is not excessive. Nice work.

Are you going to run the BBC flywheel? On our new build I considered the BBC 153 tooth flywheel, but when we mocked up everything both the Ford & Chev. starter interfered with my new pan is the pocket area. So I just went with the Ford 164 tooth which gave me just enough clearance.
BBC Seal

We anticipate running the 168 tooth flywheel and just wanted the ability to easily find a clutch. I haven't gotten far enough along to mock up the starter and flywheel.
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