Stg 11 Rear Main Seal.

[9SECVSIX]

#16 Block . Can't seem to get the rear main seal tight , am using a BS 40096-1 Fel-Pro. Seem to me I read years ago that there were 2 BBC 2 piece rear mains seals with different diameters. Just wondering if there's a better one that this one am using. The crank does not have a knurl but one would think a dual lip BBC seal would be tight. FWIW I have been using the rubber side strips and pins. Any suggestions. Thanks.

 

[turbodave231]

Could this be an early 016 block? Early 016 blocks used standard Buick rear main seals. The later 016 blocks casting date 85 used BBC seals. Later blocks had billet #4 caps.

You can usually tell an early 016 block by the cast iron #4 main cap. Early early 016 blocks have #1 and #4 cast iron caps. Both early blocks have pipe plug fittings in the lifter area.

Lots of variation in Stage blocks...The best I can tell, they made changes from batch to batch!!

Dave

 

[9SECVSIX]

Hi Dave
It's a late #16 has 4 billet caps..definitely a BBC seal, I have changes it several times. Did BBC cranks of old that used this seal have knurled crank seal journals Like I said before my crank does not have the knural..someone suggested roughing the surface with emery cloth, that sounds a little crude. I will do it over again..maybe am missing something.
Thanks for your reply.

 

[NCTURBOS]

FWIW, I've had quite a few "016" block guys buy the GM rear main seal from me in the past. Most complained about the Felpro and said the GM was much better. Maybe give it a try?


K.

 

[Lee Thompson]

Don't rough up the journal

Hi Dave
It's a late #16 has 4 billet caps..definitely a BBC seal, I have changes it several times. Did BBC cranks of old that used this seal have knurled crank seal journals Like I said before my crank does not have the knural..someone suggested roughing the surface with emery cloth, that sounds a little crude. I will do it over again..maybe am missing something.
Thanks for your reply.

Please don't make the journal rough--it should be smooth---if your block takes the BBC seal it DOES NOT need knurling. As the other guys have said there may be a difference in BBC seals---the seal it self should have knurling lines molded into it--look for that. Best of luck.

 

[9SECVSIX]

Please don't make the journal rough--it should be smooth---if your block takes the BBC seal it DOES NOT need knurling. As the other guys have said there may be a difference in BBC seals---the seal it self should have knurling lines molded into it--look for that. Best of luck.

Thanks Guys. I will get a GM seal and compare it to the Fel-Pro. Lee my seal did have knurling lines...There seemed be lots of tension on the seal lip....I was quite suprised to see the new one leak as much as it does.I did not have this problem with my previous Stg #16 block motor.I will leave the crank journal as is (smooth) I really didn't buy that rough it up suggestion.

 

[Lee Thompson]

Od

There is a different OD for the seal area as to whether it was machined for a BBC seal or Buick seal---I don't know what they are---I remember it to be about .013 difference.

 

[9SECVSIX]

BBC rear main seals.

I purchased a couple new seals, another Fel-Pro and a Genuine GM at 3X the price of the Fel-Pro. took some measurements and it appears the Fel-Pro will put more tension on the crank journal..FWIW I doubt the outside lip on the GM seal will even touch the crank. It appears to me the Fel-Pro will make a tigher seal..I will wait until I remove and inspect the present one then decide which one to use.

 

[SNOWBIRD]

Following Closely

 

[Lee Thompson]

Just a thought

What if you put a thin layer of RTV sealant between the block--cap and seal?

 

[9SECVSIX]

What if you put a thin layer of RTV sealant between the block--cap and seal?

I did that Lee..Like I said before I went to great pains to get it tight. I know the block has been align bored twice since I purchased it..am wondering now if the shop machined the seal ridge when they did the caps, if not this might put the seal somewhat out of round. I can't remove my custom pan unless I pull the motor or the transmisson..I've decided to pull the transmission and flex plate when I get the motivation.