Has anyone used the grooved main bearing(big block)that Mancini sells? The DIAGONAL-CUT grooves...that supposedly help with relieving rear main seal oil leakage! I DO NOT want any oil leaking out the back of the engine..as in the past! Thanks in advance for the info! Randy B.

Hi,Cab! Yes..on my 440 for the GTX! I was just curious if that design was helpful with oil control,and WHY it relieved pressure to the rear main seal...which we ALL know,can be a MAJOR headache!

I was looking at the main bearings from my 05 crate hemi and it has tha tbearing , and looked to have oil dripping offthe back end when I got it

i think the only way to stop a rear seal leak is to go with the old rope seal. i don't see how a neoprene seal can keep oil from getting through the grooves on the crank seal surface. when i build a stroke 493, the mopar crank i used had a smooth seal surface( no grooves), never leaked a drop of oil. think about it. seeya

MANY OPINIONS on this,PLEASE....before I go out and buy gaskets..bearings,rings...and SEALS! THANKS!

Not needed if the seal and retainer are properly installed, with a good quality seal.

Todd..have you been using Greg's rear seals? Are they neoprene? He's got some good stuff!

Myself I like useing either the right stuff, or the stuff that ford sells for the power strokes. Its a very thick and tacky grey sealer, and not much is needed at all. I dab a very slight amount of that stuff on the seal ends, make sure things are dryer than a popcorn fart, and put the seal in with the sealer as the lube to slide the seal housing in the block. Dont have leaks in my big block.

THat ford stuff is about 17 bucks for a half a calking gun tube.

Kasey

I really need to find the time to sit down and write out a "How To" on Mopar rear main seals.

Maybe title it "Myths, Legends and Old Wives Tales"

#1 YES you can use a "rubber" rear main seal on a "O.E.M." crankshaft that has a knurl. Chinese "Aftermarket" cranks have been known to need attention.

#2 Shaft seals are designed to ride on a film of oil. Just like a bearing they don't last long at all without lubrication.

#3 Those that "feel the need" to use Silicone/RTV on their rear main seals.
1) have no confidence in the seals they are using from the get go.
2) have dodged a bullet for years, so it must help.
3) believe everything they read.

I'm sure there's more but don't have the time to go on right now.
Let the silicone users flaming begin

Randy, Yes Todd does use and offer my rear seals. He stocks the Fluoroelastomer aka Viton (Viton is a trade name of DuPont)

I have seen more leaks from the rear seal housing installed incorrectly, or with way too much goop rather than the seal itself leaking. I sure dont use much at all, only enough to seal the two parts, and the only place I have dry, is the mateing halves that touch eack other.

THe crank should have an oil film on it like Mr roadhazard said.

Honestly I dont really worry about it when I am putting an engine together, just have a routine and it works. I dont scratch my head an ponder if thie damn things gonna leak or not cause eventually it will.. LOL

Mopar made Chrysler marine motors that came in standard and reverse rotation for boats with dual motors, the reverse rotation crankshafts had the stock knurling in the opposite direction than the standrad rotation motors do, those reverse rotation motors used the rope seals, not the neopreme seals used later in OEM application. You can turn and polish those cranks down to get them smooth so you can use a neoprme seal in them A mchine shop I deal with bought seven stroker cranks(Chinese imports I'm sure)recently that have the knurling put on them backwards He turn the knurling down .007 to smooth the seal area and is having them polished also. Leaks are caused by a reason, figuring out the reason can be challenging

with cab. i don't care what anyone say's. as long as there are knuraling on the crank, oil can still sneak under a smooth seal edge. i used a billet seal retainer, installed it properly & still had some seepage. when i went to a stroker crank, ( no knuraling) no more leaks. what's that tell ya. i'm not meaning to step on anyone's toe's, just past experience. seeya.