440-426-My 572 (World Block) rear main oil leak

[Daytona Guy]

I have rebuilt a few 440's and now have a 572 HIMI. I loath, hate, frustrated and angered, lol, about the rear main seal design - the split rubber seal in the big block. I have never, and I mean never, had one of these work. I rebuild 4 440's and painstakingly and carefully installed this peace of crap design thinking I'm the one that can't get it right, and everyone of them dripped oil. 

I bought a 572 HEMI from Indy Cylinder Head, and this RMS leaks too, and is getting a little worse every year. I don't Blame Indy, I think the design is BS. You can't split a seal and expect silicone to seal it. I have owned many 440's with the "Rope" and they never leaked on me, if you kept driving them. Does anyone know a redesign rear seal that implements a seal that is one piece??? Or, do they still sell the rope? Would be eternally grateful if someone here has figured this issue out, or am I just this unlucky, or just that bad?





Dane 

[Just 6T9 CHGR]

I redid my rear main seal for the second and hopefully last time about three years ago with the Billet retainer kit from Hughes Engines.

So far so good.   Did it on my back with the engine in the car...PITA but do-able..



http://www.hughesengines.com/Index/products.php?browse=category&level0=RS0gQmlnIEJsb2NrICAoUmFpc2VkIERlY2sp&level1=R2Fza2V0cyAmIFZhbGxleSBQbGF0ZXM=&searchmode=partnumber&page=6&partid=27110

[Challenger340]

Specializing in Machining/Building BB Mopars/Hemi's as we do.... and with nothing leaving without being Dyno'd as policy.... and it can be fairly embarrassing to fire up the Customer's 572 KB Hemi or even a resto 440 on the Dyno and watch the drip... drip... drip... from a rear main leak.
So we test every rear main during crank assembly to make sure it's right, dry, and doesn't leak.... before we continue feeding it Pistons/Rods/etc to a complete assembly.

We install the pan with just the Crank installed in the Block, fill with Oil.... and then hang each engine on it's end to submerge the seal in Oil for 8 hours !

It's NOT the 2 pc neoprene seals that are the problem..... it is the 'concentricity' of the recess grove in the Block the seal half sits in with the Crank itself.
The groove sometimes locates the seal half so only one side has good sealing contact with the Crank.... and the other side poor contact = leak.

Next time you are assembling do this
with the block upside down, install the upper seal half flush, then the Crank, and observe both seal half 'lips' on either side from compression/sealing against the crank.
SEE the problem ?
Now when doing final assembly.... simply install the offending/not sealing side up about 1/4" from the parting line, do the reverse in the retainer, then pry/use the retainer as you install it to 'drag' the offending/not sealing lip seal side over into contact with the crank as you tighten the retainer bolts.

[Brass]

Make absolutely sure you have good crankcase ventilation.  The kit from Hughes is a good one.

[Challenger340]

Make absolutely sure you have good crankcase ventilation.  The kit from Hughes is a good one.

We find it doesn't matter what whiz-bang... Billet 007... "ancient Chinese secret".... rear seal retainer you use, you can still have a leak.... because the retainer is NOT the problem ?
The |"problem"....
is the location of the groove in the block ! and once you understand the problem and "how" to correct for it during assembly = problem solved !

We just use the stock 50 year old seal retainers on all our engines.... and we NEVER have a leak anymore !