Rear Main Seals

[Al W]

What is the best seal to use for a R.B. big block?

 

[NOSTRT980]

https://www.manciniracing.com/bilrearmains.html

 

[69Bee]

I use the OEM seal retainer, and the seals from the Fel-Pro gasket sets. Have not had an issue yet with leaking.

 

[bigbluedodge]

I've used the Mancini Racing seals and the stock seal retainer.

If you have studded main bearings make sure the back ones don't hold the pan off the gasket. I've had to shorten the left rear stud on 2 different engines ( I was using custom pans: one Milodon and one Chinese). The blocks weren't drilled deep enough.

Bryand

 

[khryslerkid]

I used this set from mancini for the stock retainer. Follow the instructions included to the letter.

Remember to use sealer to fill the top of the retainer bolts when installing the pan. It can leave a place for oil to escape if you don't.

https://www.manciniracing.com/subheviremas.html

 

[Richard Cranium]

I just installed both of these...

 

[91r/t]

I've used the Mancini Racing seals and the stock seal retainer.

If you have studded main bearings make sure the back ones don't hold the pan off the gasket. I've had to shorten the left rear stud on 2 different engines ( I was using custom pans: one Milodon and one Chinese). The blocks weren't drilled deep enough.

Bryand

Had the same issue. I ground reliefs in my retainer to clear the studs. Found out the hard way and had to tear the pan and windage tray back off mid install and relieve the retainer. Boy was I REAL HAPPY about that haha.

 

[PurpleBeeper]

It is also important to "offset" the 2-piece style rear main seals slightly so that the edges don't align directly with the spot where the block & rear main seal retainer come together + add a drop of adhesive to the edges of the seal halves.

 

[Frank Mopar]

http://www.fastfishautoparts.com/Performance-Engine-Seals.html

 

[Richard Cranium]

http://www.fastfishautoparts.com/Performance-Engine-Seals.html

Interesting. Have you, or anyone here, installed that type of seal?

 

[Frank Mopar]

Interesting. Have you, or anyone here, installed that type of seal?

I did. With the engine in the car. No leaks happy to say

 

[khryslerkid]

It is also important to "offset" the 2-piece style rear main seals slightly so that the edges don't align directly with the spot where the block & rear main seal retainer come together + add a drop of adhesive to the edges of the seal halves.

We have a "Sticky" here on this... post #10 for the PDF instructions.

https://www.forbbodiesonly.com/mopa...-thread-on-rear-main-seal-replacement.127618/

 

[dvw]

Interesting. Have you, or anyone here, installed that type of seal?

I haven't used this seal yet, but I will next time around. For one reason only. The factory style seal won't hold crankcase vacuum. The red seal never leaks when installed correctly.
Doug

 

[slepr1]

I just used the following from 440 source on mine. No leaks on dyno break in or pulls.

http://store.440source.com/Rear-Seal-Caps/products/26/