Bbc rear main seal question
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,300
Likes: 36
From: Allen Park Mi
Bbc rear main seal question
Question on a big block rear main seal
I have the blue fell pro and when I just set the seal in the block, it sticks out on one side about 32nd -1/16” of an inch
Does this need to be filed down flat before you do the offset? I see nothing about this in the instructions, but I would presume that once torque the cap down it’s gonna create a gap.
any wisdom here?
I have the blue fell pro and when I just set the seal in the block, it sticks out on one side about 32nd -1/16” of an inch
Does this need to be filed down flat before you do the offset? I see nothing about this in the instructions, but I would presume that once torque the cap down it’s gonna create a gap.
any wisdom here?
Melting Slicks
Joined: Mar 2010
Posts: 2,266
Likes: 374
From: Randolph nj
You don’t want the seal to match at the seam you want it to be offset to seal the crankshaft .. get the other half in the cap and rotate it about a 1/4 then tighten the cap
is it the right seal
is it the right seal
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,300
Likes: 36
From: Allen Park Mi
I understand that but what I’m saying is that when test fitting, the seal is about .040-.050 oversized
So if you double that for both the cap and the block, the seal will distort when you lock the cap down - regardless of where the seam is
I understand the 3/8 of an inch offset, but what I’m asking is did the seal
need to be trimmed so that it’s perfectly sized to the journal
Melting Slicks
Joined: Jul 2006
Posts: 2,269
Likes: 480
From: Salmon Arm, BC
It's slightly oversized like that to allow for a slight compression seal as the parts are assembled.....and we all know that doesn't work very well. I use a Q-tip to apply a small amount of RTV sealant to the ends of the seal for added leak protection.
