Neoprene Seal

DaveB

Member
The Model B engine I bought has a bad rear main leak. Upon inspection, the crank at the rear main had one of the two oil slingers machined off and a two piece neoprene seal in the block and half in the aluminum rear main cap.

Looks like I am stuck to find out who makes this seal or have the other slinger machined off and use the new cork/neoprene seal advertised in Snyder's catalogue.

Any ideas of who makes the two piece seal I have or if I should do the machining for another modern seal.
 
Snyder's has one part number B 6335 M;
 

Attachments

  • rear seal 1.JPG
    rear seal 1.JPG
    21.8 KB · Views: 56
the black neoprene 2 piece seal is probably a Burtz seal. Another common 2 piece seal is from a 350 chevy, which requires a spacer be tack welded to the crank where the slingers were ground off. A common problem to both types is leakage around the outside of the seals. Many shops installed these with permatex hardening sealers like the red aircraft sealer. I have heard both RTV Ultra Black and permatex #2 recommended as better. Terry Burtz recommends Permatex #2 on his seal on the outside surfaces with a little on the parting surfaces too..
Another problem arises if the seal surface on the crank is ground too small. The photo Mike posted above looks like a Burtz seal and that would be the correct seal diameter if it is. Ask your supplier to be sure.
 
One more area where those seals can leak: the upper aluminum seal that fits into the block can leak around the outside too. When I assembled my b engine with a Burtz seal, I flipped the engine over, filled the drain tube and bearing with oil and then pressurized it to 10 psi as a leak test per Terry's suggestion. This allows you to find any leak before you install the engine...a real good thing. My seal leaked oil from between the iron casting and the upper aluminum seal. I re-installed it with a generous gob of permatex #2, and on the last test, no oil came out the rear.
 
Thanks Pat and Mike. Terry sent me an email with the information and source I needed. I think the one I have had been installed improperly. Will try again. The information you provided will be very beneficial. This is a very good running engine other than the leak it had. While apart, I will have the engine completely rebuilt and take it to Turlock in January if finished by then.
 
The cork and neoprene seal shown in the Snyders catalogue was designed by Ed Barnett in E. Flat Rock NC. You can rech him at 828-699-5639.
Don in SC
 
Back
Top