Rear main seal

[31a]

I am using the new neoprene, it leaks and I know of three others that also leak. My thought stay away

 

[hardtimes]

I am using the new neoprene, it leaks and I know of three others that also leak. My thought stay away

Hey 31a,
What I'm wanting to know, is the 'new neoprene' that you are using....the Burtz seal which is one piece, or some others' creation, i.e.---some supply place/seller ? Quality is number one,eh ! Proper installation is also #1, but if seal is quality #2...well ?
Reason I'm asking/curious, is that I've run a Burtz rear seal for 10 years in the B that is in my '30 roadster...without a drop of leaking ! I'm aware that the crank seal surface has to be 'dead smooth and concentric', to expect it to seal properly. To prove this and as an example of proof...I had a NEW crank to install at that time...so the Burtz worked !
Now need to do same operation again (B engine again)...BUT no new crank, but reground this time.

 

[Terry Burtz Calif]

The "Burtz" radial lip seal is made of Nitrile, not Neoprene.

Evey type of seal needs the seal rubbing surface to be concentric to the rear main bearing journal and smooth to function. Main bearing clearance also needs to be tight.

Packing type seals (asbestos, teflon, cork, felt, etc) rely on the compression of the material when the engine is assembled to maintain contact with the seal rubbing surface. When they wear just a little (bearing clearance increases), seal compression is lost and they will leak.

Radial lip seals are different because they have a flexible lip to maintain contact with the seal rubbing surface. The flexible lip is able to maintain contact with the rubbing surface much longer than packing type seals, however they will leak when bearing clearance and RPM's become large enough where the lip of the seal cannot respond quick enough to maintain contact with the rubbing surface.

Clear as mud?

 

[Walt Dupont--Me.]

Hey Walt,
You've got to post some pictures here of your A/B builds,eh !
You do nice work and post V8 finished product...but not fours ?
Question:
Sounds like you used the Burtz rear seal ('over end of crank' ). WHY did you stop using that (too much work ,machining of slinger or leaks or WHAT?). Can you show any pictures of rear cap and the 'plug' operation that you use. Thanks !

No, not much work machining the slinger off the crank, any one can do it with a lathe, that can read a mic. I never had any trouble with that seal, But never had trouble a new Babbitt job. The drain pipe on the rear cap is just common sence. Just look at the cap, off the engine, you'll see that little plug it's about 7/16, looks like a frezze plug on the side of a block, drill a hole in it and pry it out, you'll usually see the pipe is screwed in and plugging half the hole, I take a chain saw file and file out threads that are inside. Run a 3/8 drill bit up the hole to make sure it's clean. Get a new plug at about any auto parts store and tap it back in. If the rear Babbitt isn't all worn out it won't leak. Walt

 

[Walt Dupont--Me.]

Hardtimes wanted me to post one of my builds. This one has welds on counter weights and insert rods, complete balance job. Walt

 

[olut]

Thank You Walt for the hint, will check this next week. So far, rear main no leak, but found another issue. Oil filling cap blow out functionality is ok, when removed, but limited, if fit on the pipe and this too far!! That explains sudden leaking to the front, easy fix, new cap, nicer looking one....

Once again, thanks to all for your helping input in this matter, for a newbie, who has just experience on V8/5Lit/twin turbo diesels at HP>390 these help was essential, thanks

Albert