The best Rear main Seal for a 440?

I've heard the Mancini rear main seal kit is the best. Is this true? What would you recommend for a stock 440 rear main seal?

A stock crank should be knurled. That is always the first thing to look at. The other thing to pay attention to is if the rear main is currently leaking. Leakers sometimes are due to poor machine work and those can be hard to fix. Leaking caused by worn out parts can usually be fixed.

I have been using the billet Mancini seal for the past few years.
I still have leakage!
Mike

I just built a engine with a billet retainer and viton seal. Leaked like a sive. Replaced
It with stock retainer and a black felpro from the parts store and its dry as a bone.

If the crank has stock knurling, isn't it required to use a rope seal? Smooth crank surface gets a Viton or other material.
I thought the knurling would wear away a rubber seal quickly

I have the billet Mancini rear main and it doesn't leak a drop of anything.

I have one that just got dyno time only. No leak at all. Then, one that leaks quite a few drops after a drive (my buddies car). Both billet seal retainers.

Edited, I have had less leaks with a stock seal holder than with the race blocks and their brand seal holders
I keep the stock seal holder when I destroy or get a customer block in that is not savable They work really good

I always use normal Fel-Pro replacement rear main seal and the factory retainer. No issues.

How many of the "no leak" rear mains also use a vacuum pump or header e-vac ???

383/432 Stroker that I built four years ago - Zero drips - Street motor - Factory PCV and Three Nipple Breather 1971

I also use the Mancini Billet - Brown Viton Seal - Second motor that I built with great results

Seal clocked at 6 and 12 for me anyways helped align the retainer using those alignment studs

O rings on side of retainer with a little Permatex Black RTV


If I was buying today

I would probably look at Hughes Engines Retainer Kit - They have a pressure relief area built into the retainer like the factory unit

I have 3 of my own here...one has a vacuum pump. The other 2 just have breathers on the valve covers. Never been a fan of the header evac setups.

i had the samr results on a 520 ci.rb

We're jinxing ourselves even talking about this stuff. This discussion alone causes leaks. It's not good to talk about it.

I've only used the ones from old MP kits and Fel Pro kits.

They have all had a number molded into them: 4227926. I had to look really closely to see it.....(It's not hard to guess whos tooling they came from).

Avoiding snafus during install + the side seals seem to cause alot of problems.

Though the white "swells up when soaked in mineral spirits" side seals never really
gave me any trouble, I always thought they were a pain to install and I used up my last pair several years ago on a 440 re-ring.
don't believe they are made anymore (were they asbestos or something?).

So on a modern build, myself I substitute RTV for the side seals. I try to inject it inside the groove
as much as possible and also pack that area using putty knife/fingers and so on.

If I remember right, the new seals don’t align over the knules, it’s on the smooth part. They have to installed in the right direction too, bevel points into the engine, like a timing cover seal. And the retainer goes on DRY no oil film, sealer will not stick to oil. The whole area is sprayed down with disc brake cleaner.

I have used a thin layer of adhesive silicone on the back side to hold the seals to block and seal holder and i ALWAYS use wheel bearing grease on the lip edges of the seal and on the main seal area of the crank surface
I have never tried installing the seals and crank dry, NEVER

I did that on my current 451 and it worked perfectly. I just made sure to get the seal holder and the block operating-room clean before applying it.

I just bought and installed the Mancini rear main seal, and it solved my leak issue.

Me too. Customer had a bad leaker on his motor. It was a fresh rebuild that had cam and piston problems. Just finished it about two weeks ago. No more leaks with the Mancini seal. I also bought the extra cost orange seal with the billet cap.

I’ve done two on 440’s, one in the 90’s, a Mopar Performance seal, and another in the 00’s, a Superformance orange seal. Neither leaked.

I've been doing it that way since about 1975.

RTV cures from exposure to moisture, inserting a wet pipe-cleaner into the wet RTV not only promotes fast cure but also expands the RTV into every corner of the groove.

Great feedback so far guys. Keep the tips coming, they are very useful. Thanks!!!

there was a thread recently that showed a billet retainer modified to resemble the engine side of the factory retainer.
this acted as a deflector, throwing the oil back toward the pan.
i'm too stupid to know when that was, or if i did remember, i couldn't link to it.
maybe someone remembers this ?
help out an old doofus with "oldtimers" and CRS please.

Not talking about the seal just the retainer, once oil is on the side pieces they expand tight, rtv in the corners and bottom, Vaseline on the crank where the seal rides

Here's mine:

that's the picture !
thank you sir !

Interesting, I have an old pan from a 71 New Yorker with a 375 horse 440
that has a baffle at the back of the pan, "U" shaped to help keep oil off the seal.

I wonder why that wasn't used on other hipo cars, or was it??

Joe

that's interesting.
i have never seen anything like that.
do you, by chance, have any pics of that pan ?

Moparx, send me an email, jlatessa@roadrunner.com
and I'll attach the pic to you.

Format not allowed by MOPARTS

Joe

I have owned and used several of those type pans also I think Mopar started using them in 1971 on the C body cars and maybe in the BB Cordoba also later

I think when I remove the pan on one of our cars, I may cut out that baffle and attach it to the 6 Qt. pan.

the sump baffle is the best I've seen on a stock pan too.

Joe

Why not build a duplicate of that rear baffle and use it instead of ruining the stock pan
How about you making a crankshaft scraper for the passenger side of the block now to use also

OK, I knew someone would suggest that, I agree.
As far as a scraper for our cars, I'm not sure we would benefit much as they both shift below 6000.

I'll take some measurements and I know someone who waterjets, so maybe I can make a few.

Joe

As an aside, it looks like the baffles are brazed in, right?

Here's a pic of the 187 pan...Joe

Looks like the main baffle is spotwelded, but the
rear baffle brazed, maybe not enough flange or room

Fast Fish auto parts

You're welcome

How has it worked out for you in all that time?

THANKS for the pic Joe !
in all my years, i have never seen a 187 pan like that !

That is not a stock 187 pan
Someone with good skill added all of those hand made pieces
I have used many of those stock pans that I added front and rear baffles along with the stock Mopar windage trays and home made crankshaft scrapers to to use in 1967 to 1976 A body cars with BB Mopar motors in them for street and strip use with good results
Mine didn't look as good as that one though

I bought the 71 NYer from a person I knew and was from my town.

He was an older gentleman who bought the car new and was not one to lie when he said
the engine was as he bought it and ran fine until he had to give up driving because of eyesight problems

The rear baffle as you see does not look like someone cobbled it together, it looks purpose built for that application.

I am of the opinion it is stock.

My 2 cents....Joe

PS the rear baffle is sheet metal, It just looks like a thick piece of steel.
I had to be formed in a die specifically for that part.

that's how i took the rear baffle to be, sheetmetal with the edges bent down for stiffening.
regardless if factory or not, it's an interesting pan for sure.

I should have been clearer that I have not seen a 187 pan with any baffles in them but all of the ones i have bought and used where from pre 1971 cars
I have seen both of those baffles used in later year oil pans on the Cordoba motors, but they weren't 187 stamp pans
This is another good example to never say never when it comes to things car makers have done on production parts
OP, do the spot welds on the rear baffle look exactly like the ones on the pump baffle?

No room to beneath the baffle to get a spotweld tip in there, it is brazed.

Joe

Well, so much for my eyes, after cleaning, I can see the spotwelds too!, but smaller
than the sump welds

The factories quit doing manual welding years ago
Some one added that on to your pan, probably the same thing on the center part

Fast fish one piece rear seal and a billet retainer with the dual side seals per side..

There was an NOS 893 pan for sale on this site, rear baffle brazed in place.

https://board.moparts.org/ubbthread...7/filename/parts%208-24-2020-2%20064.JPG

I think that is a stock RB,B 1967 to 1969 A body oil pan. Not a stock 1966 to 1972 C body oil pan

I am going to start replacing the rear main on the 440 in the Ramcharger, Dan at performance only did the bottom end, and I was about 15 years younder, and didnt assemble it with a rope seal, it leaks BAD!, Im doing this in the truck, thank god its a lifted 4x4, and the pan comes out easily. BUT with that said, Im a one man show, and Im curious if anyone has ever taken the main caps loose and let the crank drop a bit to aid in installing the new seal. Or will that cause a front pump seal issue on the tranny?

I have bought the Lisle sneaky pete tool, and I also plan on swaping the billet rear seal retainer with a OE retainer I have. I am also going to use the Mancini racing 1 piece gasket/windage trey for the oil pan gasket.

Has anyone ever drilled a few drain back holes in the plastic trey? I see they dont really have much of anything for drain back holes.

Kasey

Replacing a two piece seal with another two piece seal? I was able to push out an old two piece seal and push in a new two piece seal without touching the main caps. The Mancini windage tray looks like the same as the Summit one I use unmodified and I haven’t had any issues

Im taking the old Viton seal out that leaks like a sieve, and putting the correct rope seal in place, and have had issues getting them pulled in place.

I see, I’m no help there

I’m pretty sure you’re not going to pull a rope seal around the crank. Rope seal has to be put in the block first then seated with a special saddle tool, then trimmed. Is the crank journal knurled?

How many have used the fast fish one piece seal? I have one leaking and thought about going this route, but id like some reviews on how they have worked out.
Matt

Mine leaked a little on the dyno. Installed as directions said. Threw it away, put in a felpro black seal, staggered parting line about 3/8”, no leaky.

I am a chevy guy so I openly accept rear seal leaks are part of the OEM rust protection package.... my only mopar is a junk 440, max piston to wall forged pistons, 0.030 - 0.035 ring end gap.... after several thousand miles on the street with a single pcv valve...zero rear seal leaks... the fast fish rear main is a f-ing miracle.

I'm curious how a billet rear main seal retainer is different / better than the OE piece.

i use adhesive silicone, not Gasket maker silicone to seal up the seal holder between the block and the seal holder on both sides and smear it in between the seal holder and block on the bottom of the seal holder also. I use a narrow, thin, putty knife to do that
No main seal oil leaks for a long time on many (100+) B and RB, 426 hemi motors since doing that

My 470 is using the Fast Fish rear main seal. So far so good.

what main seal retainer did you use, and how did you seal it to the block ?
did you open the retainer bolt holes to allow the seal to find it's happy spot to seal ?

The original

SOOOOOOOO, Nobody has replaced a rope seal in the vehicle?

Im going to try it, Ive got nothing but time, and Im fairly patient...

I tried long time ago, not going to happen. I said a while back, seal has to be seated in the block with a special saddle tool, then the ends have to be trimmed. Look it up in a factory manual.

Ive looked that up before, Ive heard of several doing it with success, I guess Ill give it a shot, im a tech by trade, worst case is I have to pull it out and do it. Engine could use a paint job, and a set of 440 source heads.... LOL

Is the seal surface on the crank knurled?

I put one in on an engine stand (400 olds) the proper way, too. Which requires clamping and trimming. At the end I could not accept the required turing torque with the finished product. Ripped it out and put in a modern replacement style and will never waste my time on a rope again.

I can't imagine doing this in a car. The crank has to come out.

I'll be the first to bet you will end up doing it with a replacement seal.

I have made that mistake once of replacing the early stock rope seal with the motor in the car, never again
Mopar and probably others had a special tool for that, the bad part was you had to loosen or and remove most of the main caps which let the crankshaft weight hang on the timing chain while doing that job, not good

Same here. I have never had a rear main leak.

Since I said that, mine will probably leak the first pass this weekend......

Same here, put it together than let it sit for a day to dry the sealers.

Nick just fixed a 383 that leaked like a screen door on a submarine

I had not either until recently. I had purchased 6 or 7 rear main seals during covid as I had three engines going together and always something in the works. Well my 64 had a small leak from the rear main, not a huge deal but I HATE leaks. I did not build the engine in the car originally. So I pulled it apart to look it over and fix the leak. Going back together I used one of the seals I bought in 2020. Put it back together as I always do nothing different. It went from a small leak to a gusher!!! Driving it around the block I saw it loose all pan vacuum and by the time I hit my driveway I was leaving a trail. The seal I pulled out of it was the same color and likely brand as I used. So I ordered a new seal from another manufacturer and no issues. So looks like I will throw away the remaining seals from 2020 as that is the secind one that leaked. My Predator had a small leak as well after being on the dyno and a few passes on it.