best rear main seal ???
Thread Starter
Safety Car
Joined: Mar 2002
Posts: 4,411
Likes: 1
From: Okeechobee Florida
best rear main seal ???
ok...i like chevys as much as anybody here but i dont know as i ever remember seeing a SB that didnt leak oil from the rear main...
so to those of you that have built them that do not leak...
whats the secrete???
so to those of you that have built them that do not leak...
whats the secrete???
Racer
Joined: Jun 2004
Posts: 322
Likes: 0
From: The Dirty, Dirty South
I leave a little "overhang" on each side and put rtv on the cap. It's worked so far, just don't get any rtv on the seal. Also, you gotta be really careful w/ the seal, any damage at all, and it will leak!
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Other than the obvious crap with the rope seal which in any car using it, leaks like a seive, you can get a later SBC block and have over with it, ...that's ONE cure....
BUT, on Pontiac engines which all came originally with rope seals and all of which leaked to varying degrees throug the years,....there WAS a cure, for the 455 engines that is...use the 500 Caddy neoprene seal, it was reinforced with a hardwire, and consisted of two crescents, one for the block which had to be end gapped to the one in the main cap....use them correctly in the Pontiac rear main, and seal the end gaps with a dap of RTV, and the thinnest coating under the main cap, which I do to any engine to stop the broach marks from passing oil weepage....and you got a near perfect seal.....
I understand the 400 Pontiac blocks, which had smaller mains diameters, FINALLY got some attention from a seal maker with a similar cure.....and I have to ASSUME someone got smart with the SBC also....
GENE
BUT, on Pontiac engines which all came originally with rope seals and all of which leaked to varying degrees throug the years,....there WAS a cure, for the 455 engines that is...use the 500 Caddy neoprene seal, it was reinforced with a hardwire, and consisted of two crescents, one for the block which had to be end gapped to the one in the main cap....use them correctly in the Pontiac rear main, and seal the end gaps with a dap of RTV, and the thinnest coating under the main cap, which I do to any engine to stop the broach marks from passing oil weepage....and you got a near perfect seal.....
I understand the 400 Pontiac blocks, which had smaller mains diameters, FINALLY got some attention from a seal maker with a similar cure.....and I have to ASSUME someone got smart with the SBC also....
GENE
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
I used the GMPP "Nascar" rear seal from Scroggins Dickey as I read this was a good choice and used Hylomar on the block mating surfaces. Im now getting a couple of drops in after a few days sitting. I did the job 2 years ago.
The seals ends went in dry and I put mating ends right even with the block mating surfaces. Maybe its better to offset them?
Brent...
The seals ends went in dry and I put mating ends right even with the block mating surfaces. Maybe its better to offset them?
Brent...
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Burning Brakes
Joined: Oct 2004
Posts: 986
Likes: 23
From: Florence SC
I have found success using a mr. Gasket single lip seal vs. the felpro double lip in small block chevy's. When installing try using just a little wd-40 for seal lubricant instead of motor oil, then a dab of rtv on the seal ends, rotate the seal ends off of the main cap mating surface 1/4 to 3/8ths of an inch. One other thing to check is the seal direction, I replaced a leaker for a customer once that had been installed backwards, It didn't seal very well. 
