I need some serious help here. The battle I have been having with this rear main seal is going to affect my health-seriously.

The saga begins: Customer brings previously rebuilt (18 years ago) 440 in for freshening/updating.

It is a 440 with a NEW stock stroke Eagle crank, Eagle H beam rods, reused Wiseco pistons, 915 heads etc...

Customer has a 69 RoadRunner 4 spd car and he is the original owner.

1st attempt: Engine runs great on the dyno but seal leaks a few
drops.

2nd attempt: I figure I missed something with his original retainer and proceed to get pan gaskets ordered so I can take pan off and "fix" rear main. I remembered that I did not have any venting or breathing in the valvecovers except for his original PCV valve hooked into the back the carb. I figured I generated too much crankcase pressure the first time. Hook engine to dyno and fire it up with open valve covers--no leaks until I complete one short pull. Engine makes great power but leaks again--same spot.

3rd attempt: Customer is awesome and supplies a Mancini billet retainer. I verify endplay .005", crank seal journal out of round .0013" and assemble with new Victor rubber seal. All looks good and normal. Re-dyno. Warm engine up---leaks worse than before. No pulls are performed.

4th attempt: Tear down, remove crank, install rope seal left over from a Pontiac gasket set. Polish seal journal with highspeed crank polisher. Feels better, looks better. Re-dyno. Leaks same as before. Install pressure gauge on dip tube and really look for signs of blowby none detected.

5th attempt: Tear down, hand grind with pencil grinder "anti-leak" grooves into rear main. The grooves point forward and this looks like it may do the trick. Prepare different rear main retainer (OEM)surface .005" in cap grinder (per my usual prep). Install another new rear main rubber seal with aviation sealer under rubber halves instead "RightStuff". Re-dyno ran engine 1300-1500 rpm for 15 minutes while I layed on the floor with a flashlight watching rear main. On the 13th minute a leak began right before my eyes. Remove engine from dyno and back on the stand. All signs are pointing to a rear seal area that is too rough or something.

6th attempt: Send crank to crank shop where seal journal is ground .005" and built back up with chromium ($$$$$) and finish ground. Crank shop assures me he has seen this many times and this is the only fix.At the same time block is torn down and re-honed/ re ringed to rule out blowby. I check the seal surface for out of round this time it is better (.0009") This time a new Fel-Pro "red" is installed and carefully (You have no idea) put into place.Back on the dyno and engine runs great like usual. I nervously watch the clock and the floor. 20 mins passes--crank flange and block is bone dry!! I run out of fuel. Get fuel, refire, warm-up, complete pull 4000-5000 rpm. LEAKS!!!!!!!!! Not much but it will not get better by itself.

Conclusion: I have built approx two dozen (maybe more) Mopar big blocks in my life and have never even been this careful and I have never ever had a leak. I have "influenced" the retainer to one side, I have feeler gauged it forward into correct alignment as measured, I have taken every conceivable measure to correct this.I had a small block Mopar leak on me once that was the result of a messed up linebore. It was remedied with a rope seal. I have a Fel-pro rope seal on the way. Short of ordering a NEW Scat crank I don't know what else to try. Keep in mind this thing has a tray and I have effed up 12 gaskets at this point.

This engine was not leaking when it came in and no line hone was performed.

The only thing that has really changed is the new Eagle crank. I am open to any and all suggestions/ experiences.

Surely somebody has gone through this. Yes I have done more online searching and reading than I care to admit. Yes the knurling is in the correct direction as the OEM crank.(It does not have knurling now) Yes it has the crank deflector just like the OEM crank. Yes I have checked the diameter of the seal journal. It is the same as the OEM crank. Yes I have installed the seal retainer with the crank removed from the block twice--it is nice and round and inline for and aft. This is not making sense. Maybe I can't see the forest for the trees? Any and all help sincerely appreciated--J.Rob

Studs or stock main bolts? if studs, #5"s are hitting the back of the pan. Not the main seal at all. Been there done that. Other than that . don't know what to tell ya.

you said it has a tray, so does it have main studs ? if so then chances are the rear studs are holding the pan from sealing at the rear and thats where the leak is coming from.

lol you beat me to it

It's not that the studs are to long , the nuts are longer and hit on the curved back of the pan causing it not to pull down tight. To the original poster: look at the back inside of the pan and see if there are 2 marks where the heads of the bolts are hitting.

Wow that sounds terrible. Keeping fingers crossed that it's got studs and the pan is hitting the nuts. I saw the same issue when assembling my 493 so I was able to fix it on first assembly. The previous owner of it had a "rear main" leak that I'm thinking was probably this very issue.

Sorry, yes studs. Definitely not the pan. Ran the engine and observed leaks without slinging it everywhere. Leak is plain as day running down from the seal journal ABOVE the pan. Thanks though. J.Rob

Not a pan leak. J.Rob

Studs. No witness marks at all on pan. Pan pulls down tight. Thankyou though. J.Rob

Cracked block, at or above the scene of the leak?

RAMM....Welcome to my hell. I feel your pain. What is the cast date of the block you are having issues with? My saga is documented in the following thread.

http://a12mopar.com/yabb/YaBB.pl?num=1424822394/15

I finally gave up and am just going to deal with it as a maintenance item on the car.

D

Do you offset the seal so it doesn't line up with the split between the block and retainer ?

Man thats crazy, i have done more bb Mopars than i can remember and never had a rear main leak. Done many Chevys, Fords and Diesels and i never had a issue.

I would try this. DON'T glue the seal in the block, nor in the cap. Only glue bottom and sides of seal retainer. Seal joints 90* from retainer surface. Never had one leak done this way. And of course I HATE to ask an obvious question.....but you are turning the lip on the seal the right way?

I might suggest that the crank journal for the seal area has been turned down to small? I dunno but Ive heard of eagle cranks having a snout that's to small for a damper by a few thou

He already said it has been cut, rewelded and measures correct

I've seen the rear main studs interfere with the seal retainer. (Actually hit the seal retainer holding it off it's mating surface.)Dave

Starting to wonder about this as well. Only problem with this is the block was dry at the back when I took it apart and I seriously doubt it has ran enough or has been traumatized enough to crack. Thanks though. J.Rob

I have tried both lined up and offset about 3/16". When I install the retainer I can "feel" the seal halves engaging into the retainer/block grooves. Thanks J.Rob

Correct it was measured after attempt #2 and it measured correct. Now it has been ground, welded and reground and left on the high end of the spec. Thanks, J.Rob

Dave, I am fully aware of the studs and the havoc they can wreak on a Mopar. ex ( enlarging thrust cap bolt holes to 17/32" for thrust cap alignment) So yes, I have scalloped the retainer out around studs and nuts. The Mancini cap was also relieved as it extra material in that vicinity, and would definitely hang up there. Furthermore, when I take this apart I always witness the mating surface and how the thin layer of sealant is completely squeezed out and leaves the shape of the retainer. Pics on the way. Thanks though, J.Rob

Monte, So you turn the seal 90* so the seam/parting line will be at the 12 0'clock and 6 o'clock position? I am willing to try anything at this point but fail to see how this helps.

The seal lips are facing inward-believe me when I first took it apart I was hoping I had it backwards for an easy explanation. Thanks though, J.Rob

Wow just read through all of it. Is your crank an Eagle?(Nevermind I see it is OEM) My block is a '68 that was cast on Hallowe'en! WTF? J.Rob

I'm sure u did this, but I'll ask anyway. Is the seal retainer flush with the back of the block? Maybe there is a misalignment issue. Last one I did, I put the seal & retainer in with no crank & checked to see how the parting lines lined up.

Did this. No crank in block, seals in, everything was nice and round. Parting lines almost not detectable by finger. Did this twice actually. Thanks, J.Rob

When you put it in the block with no crank.. did you have the
side seals in it.. I have seen where the retainer was cut shallow
on one side.. it forces the retainer over... this was a after
market retainer

No side seals were in, but I also fill the side channels with RightStuff when I install--so no side loading is present in this case. J.Rob

I'm on the edge of my seat with this one. I am actually dealing with this exact issue right now. I have assembled several Big Blocks over the years and have never had a leaking problem at the back of the block. The block and seal retainer I'm using was used in the past with a factory crank and no leak. The difference now is a Ohio Crankshaft 4.250 crank and BRC aluminum main caps. I am running it on a run stand. It doesn't start leaking until the oil get's hot and then it only leaks when you rev it. When I initially assembled it, I was a little concerned with the side seal on the one side of the cap because it didn't seem like it slid in all the way so I figured that was the problem. When I pulled the pan off to have a look I noticed witness marks on the windage tray and the gasket was chewed up there from the main cap studs. I then figured that this must be causing a leak at the back of the pan. I clearanced the windage tray so it wouldn't hit the main studs replaced the side seals put a light coat of silicone where the retainer meets the block, a small dab of the Right Stuff on the ends of the rear main seal (I stupidly didn't change the seal). I ran it again no leak when it's cold as soon as the oil gets hot and thins out when you rev it it starts dripping. I can't tell where it's originating from because everything is so clean and the Valvoline VR-1 is colorless. I bought a bottle of dye to put in the oil and will check with an UV light to try and pinpoint where it's leaking from. This is driving me crazy due to limited time to work on this stuff. I'm hoping to run it tonight. If I learn anything I will report back. Good Luck and thanks for starting this.

I used phosphorescent dye (works with a black light) to check a set of heads. They lit up like a Christmas tree at every crack. If there is a dye like this that can be safely used with motor oil, you could trace the leak easily.

There is a small oil pressure relief hole drilled in the block in the rear. It relives full pressure from the rear seal. Went thru the same problems a couple of years ago on a low deck motor, fought it all year found relief hole and cleaned it out Problem solved

I am not aware of this hole. Does anyone have a picture that shows the location of this hole?

I just checked a '70 440 block I had bare here. There is no hole that I can find? J.Rob

Never seen or heard of a hole, that relieves pressure off the seal.

Ramm, just try the sealing ends 90* apart can't hurt. And like I said, I never glue the seal in the block or retainer. Just place it in there. Place lower half of seal, put crank in, then take upper half of seal and work it around crank until you parting lines at 90*. Then put the retainer in

plug at the cam tunnel just above the rear main seal seeping?, damhik especially the welch plugs.

I know this might be a stretch but what are the odds of the seal journal on the crank not being in line with the rest of the crank? or the other way. the crank seal retaining area not in line with the line bore? i wouls at least try to check that part on the crank, seeing that that might be the 1 thing that has changed in the previous setup.

did we put engine oil dye in it,and run with black light

I would think this would show up when I lay crank in mains and set dial indicator on seal journal and it displays .0009" out of round. I called Eagle today and they say they keep it at .0005" or 5 tenths. They were of no help of course.

Also when I have had the crank out and installed the retainers-the seal halves line up nicely and I mean round and inline with each other. J.Rob

yeah that should have been good at that point. another thought would be to look at the oil feed hole on the crank for that main. is it pointed to that direction? maybe drilled incorrectly so that it would direct oil flow towards seal? seems at this point like oil is aiming directly at the seal instigating the problem.

Plug the valve covers up and put some air in it and try soap bubbling the seal area. I know of several top shelf mopar engine builders who are ready to rip their hair out right now over these dang seals.
Todd

i like that idea. i'll try to remember that one in the future.

Forgot to mention that--On attempt #4 I rigged an air fitting right where the sending unit comes out of the back of the block. I pressurized it with up to 5 psi and sprayed the crank flange--no bubbles. I realize I may have to pressurize crankcase but really at that point I may as well dyno it and bring it up to temp. I have already proven it a few times--no leaks until you rev it up @ temperature.Thanks though. J.Rob

It might pay to try an electric vacuum pump off a new car. They can be bought pretty cheap. Pretty sure Summit even carries one now.

The hole is just over the main bearing, it was clogged with machining debris I must add this was on a Indy Maxx aluminum block, but is was causing the exact problem you have

Here's the 3 retainers that have been tried. You can see the clearancing for the studs/nuts. J.Rob

have you tried another retainer?

Studying this closely I think I may have to provide more clearance between the #5 cap rear and the "deflector" on the crank. The black squiggle is where I could machine .057" off. It may do the trick. I really don't think there is any issue with the seal itself. I am leaning towards a severe oil/pressure buildup that NO seal can handle. I'm also starting to think the windage tray should be left out to provide more room between the rear counterweight and the cap. J.Rob

RAMM
Did you happen to tank the block really good before the rebuild. I read a piece by Rick Ehrenburg a few years ago and he stated that some blocks because of poor manufacturing were porous at the rear and were sealed by some coating applied to the block at the factory.He warned about possible oil leaks after a good tank cleaning as it could remove this sealant. In your case it may be seeping just above the crank and presenting itself as a seal leak. I sure feel for you on this one.
Ross

This is actually something the customer suggested to me this morning. I do not have a hot tank but I do have a very good jetwash. It was suggested that I could have cleaned out or dislodged some material that was previously blocking some porosity. I will coat with Glyptol tomorrow as it is not difficult to do. Thanks, J.rob

OK,,, I have been through this hell before.
I had my 383 engine built by the best in the business; a professional, 30 year, race engine shop.
First run it leaked on the stand. Second seal...leaked on the stand.
We pulled it apart 4 times.
We checked and sent the crank out to an expert. Perfect crank.

Finally...
He tore the engine down to the bare block. Checked everything with a micrometer. After measuring and researching we found that a small percentage of MOPAR block rear main seal retaining threads are drilled off to one side, ever so slightly. It is literately thousands of an inch off. Enough for a small leak according to Felpro.

He eventually used an OEM rear main seal retainer (they have some slop in the side to side placement. Driver to passenger side movement). He shimmed the retainer to one side the distance it needed to go to center the retainer exactly over the crank and to pull the weak side seal over to the crank surface. If you look closely you will see the weak seal side against the crank. also you will need to have the seal slightly off center in the block and retainer to have the retainer grab and pull the weak side over to the crank as you push the retainer to one side.

This is about component machine errors. DO NOT believe in crap like the type of knurling on the crank end, Rope seal fixes, and other non-mathematical crap. It's all about tolerances and measurements. Something has to be measurably wrong. either the crank is off or the retainer/block is off.
Don't grind the retainer to make it tighter. Look at the seal as it presses all the way around the crank. I believe he said he used a snap gauge to measure the exact distance it was off from center and that measurement is what he used to push the retainer over.

My engine builder now checks every MOPAR block for this error. He spent months on my engine and cost him time and money that he does not want to go through again.

It was a nightmare. I feel your pain. My engine is now dry and runs strong.

Smos011, if you took pics of your seal being off, can you post them?
I'm fighting the same issue on my 70 383 Mag. I was just about to loosen
the caps & do the rope seal thing, but your situation has me wondering.

I don't have a good pic of the problem.
But, I am telling you this is the problem. I talked to some real experts on this. It's about components. It's about math. You have to measure everything. Something is out of tolerances. Things don't fix a leak because of knurling or smooth polish on the crank surface, grooves in bearings, or the grinding of OEM retainers.Ropes seal don't last and 1960 and 70s era motors did not have rope seals. It's about tolerances.

when we found the measurable problem. We did not even have to test the solution on the stand. We knew we had solved the problem.



Here is one guys solution that started our research I found on another site. He was very helpful. Our solution was similar but using micrometers. His discussion saved my engine (he was a saint!):


Install The rear main lip seal half in the block "flush" with the cap parting line.
Install the Crank.
If your Lip Seal compression on one side, is less than the other under close inspection with a light, with the Crank in the block, you have a potential for a leaky main.
Gently, using a small screwdriver, GENTLY, insert it behind the offending side of poor compression, and "eyeball" the amount required to equal Lip compression "side to side".
DO NOT damage the back of the seal with the screwdriver. It doesn't take much.
Record the amount required to move the lip seal into equal compression.

Now dis-assemble.

Re-assemble this time, with the Block side Rear Seal lip half protruding approx. 1/4" above the parting line on the offending side.
Reverse the same Seal offset installation in the Retainer.
Now use the Retainer when installing, to CAPTURE and DRAG the offending poor contact side over into proper seal lip compression, the same amount as you recorded earlier, as you Tighten & Torque the Seal Retianer into place.
Silicon up the sides of the Seal Retainer to the Block, deleting the paper inserts. (The paper side inserts probably won't go in anyways due to the Retainer offset installation)

WOW, this is a helpful and interesting topic. Can't wait to see what actually worked to fix this.

Had a rear main seal tryed evry thing the fix. In my case had a aluminum tool made that fit the seal and fit in the main bairing put the lower seal cap on then shine a flashlight from the back the seal was to low at the block shimed the up worked grate. will never install a rear seal without testing the fit.

Thankyou and yes I have noticed this same thing time and time again. On attempt #4 I influenced the retainer to the side in order to increase contact on the weak side. I am aware of this, I have even taken measurements and shimmed fore and aft. I am all about the tolerances and my instincts say a rubber/PTFE/ whatever seal can take up a lot of misalignment. I am dealing with something dynamic--not static. Thanks for the response though. J.Rob

This is exactly the next step! I am machining a "stub" that will sit in the main journal and feature the seal journal to eliminate the crank flange. I want to "see" WTF is going on without the damn crank flange in the way. Thanks again! J.Rob

I have been putting big block mopars together for close to 50 years and never had a leak, except the stud/pan problem mentioned earlier,lucky I guess. I haven't turned a seal 90 degree's but have off set them maybe 3/8" , never has a seal leak. Now watch the next one will pour put like there's no seal in it at all. I think this block is outa wack.

All this is exactly the reason I say put the seal in the block FIRST, with the ends at 12 and 6 oclock. Then you do whatever you have to do to make the retainer slide over that seal cleanly and freely, with NO influence either direction. With it all dry and no bolts, drop the retainer on and see how it feels and look in the holes to see if it is where it NEEDS to be, not where the bolts, or those idiotic side seals put it. One thing to understand.......the SEAL is what seals the crank. The retainer only holds the seal where it needs to be. With the seal in the block around the crank, the seal IS where it needs to be. Now make the retainer cleanly hold it. This is a piss poor design and always has been, but not unfixable. You need to drill the retainer holes out, drill them, makes no difference. This is NOT a critical piece. It ONLY holds the seal, nothing else. It's just not this hard

Other motors with two piece seals don't have this issue. The reason, is the seal is retained by the rear cap and is always consistent and goes on where it should every time. BBM doesn't have that luxury but is not hard to MAKE it work in a similar way.

If you have never had a BBM rear seal leak.........you simply haven't built enough of them. But since I started doing the above procedure....30 years ago or more........no more leaks

Many also want to "face" the retainer on the bottom, to make sure it sits flush. It MAY need it, but usually not. This generally just makes the seal groove not round any more and changes the crush. If you do that and put the seal where the ends are flush with block and retainer, it will NEVER seal. Its an easy measurement to determine if the retainer NEEDS a shave. Don't do it "just because"

Here is how the cap looks after machining. There is about double the room between the back of the cap and the deflector now. I figure it can't hurt. Also I am going to try Monte's method of seal installation. Also reassembling WITHOUT windage tray. Back on the dyno later today. J.Rob

Stop grinding...
Just my 2 cents. But without a measured mathematical problem, you chasing ghosts.

Check the crank for errors. Check the block for errors.

Also, rear main seals have very little pressure on them. The oil that they stop from pushing through is from splash oil. It's not a pressure seal. It's mostly a barrier seal. You have a gap somewhere in the crank to seal lip.

Either the crank is out of tolerance or the block is off.

I know this is frustrating. I was there. Lots of advice. Most is urban legend. I even bought a rope seal at one point. Engine builder laughed. Refused to put an inferior product in the engine that would eventually fail. I was to the point of buying a new block.

My engine builder did build a aluminum billet crank plug to the exact specs of the crank. He used that to look at the issue.

Again, it's about the seal to the crank surfaces.

There is a guy who sells a one piece rear main seal. You put one cut in it.
Not sure if it will help. I still think you have to find the errors first.

Ran engine on the dyno for 90 mins. Performed 8 tests. NO LEAKS!!!!! NO LEAKS!!!!! Not a single drop!!

What did I do this time? Three things in conjunction.

1: Machine backside of #5 cap for more oil escape clearance

2: Install new normal black seals as Monte suggested

3: Omit OEM windage tray

While I was skeptical Monte's method would work--apparently it does. My hunch though tells me the windage tray was the real culprit. Don't know for sure at this point. Greatest Friday ever. Thanks for everyone's help and thoughts and possibly prayers. J.Rob

Glad you fixed it..........but I can pretty much assure you that the windage tray was NOT the problem............LOL!!!

Congrats!

WINNER! WINNER! CHICKEN DINNER! glad you fixed the problem. one heck of a learning experience.

Glad to hear you made some leak free pulls... now I'm wondering
what the REAL fix was/is

Glad to hear you got this fixed. I am now breathing a sigh of relief for you and all your frustrations that you went through. So the seal is installed 90* from normal?
When I started reading this thread and all the work that you went through, in, out, tear down, put back together, dyno again etc... to fix that leak, my thoughts were "this guy cares and goes the extra mile for his customers". Just curious now, who bit the bullet on this one, you, customer, or both. I am 4 hours away from you and am seriously considering using you for my machine work on the gen 3 hemi that is going to start sooner or later, just because of your work ethic and meticulous detail.

Congrats on getting that thing sealed up Jesse

I know it had to be frustrating

Time for a cold one !



Ron

Care to make a wager? I still could install tray and test. Seriously though thankyou, Monte. I doubt I would have ever considered arranging seals that way. J.Rob

Boy you aren't kidding about the learning experience. I have to give the customer some credit here actually. He is an older gentleman that did not pressure or belittle even once. He and I relayed experiences back and forth over the course of this saga and I could not have asked for a better person to have this happen to. I know that sounds bad, but HE supplied the billet Mancini retainer-which leaked worse than ever. HE supplied 3 oil pan gaskets. He supplied fuel when it wasn't even asked for. HE made countless trips to the shop and he exhausted every one of his resources trying to resolve this problem, all the while remaining in good spirits. J.Rob

Thankyou Onig,

Thankyou so much. I do care. I cannot just give up without knowing the answer. I will share that when I dyno'd it this last Wed and it leaked, I texted the customer right away. He texted back--"What's next?" I responded with "A 20 foot tree limb and a 10 foot rope". There were some dark moments to be sure.

To answer your question: The customer ate it in terms of some parts, and time and anguish. I ate it in the same fashion. I cannot charge someone that has entrusted me because of my expertise in a given area and I fail to deliver. This was in NO way shape or form the customers fault. I am just glad to have solved the problem. 12 pan gaskets, 3 intake valley pan gaskets, 1 set of rings and 7 rear main seals later..

Lucky for you member MattW here and I are about to embark on G3 HEMI development. Thanks J.Rob

That is correct. The seals are test installed in a pic above. J.Rob

Thankyou Ron! I am currently about 3 Bud tallboys in.

p.s. How did your 440 Stealth headed project turn out? J.Rob

Curious. Which seal retainer did you end up using?

My son and I were at MattW's place last year on his Indy head transaction. Looking forward to the Gen 3 development.

Reconditioned stock one. J.Rob

Great! Matt and I have known and grown with each other for about 13 or so years now. We have big things in the works concerning G3's. J.Rob

Just curious which windage tray WAS used - some the louvers aren't real tall and oil can pool up ?

I guess the fix was add more or open the louvers wider to improve drain back.

you mentioned the glyptol did that have any effect ?

do you have a rope seal you can install?

I think you are a little late to the party brother...........LOL!!!

when the seal ends are at 6 & 12, and the retainer cap fits correctly dry, tighten the retainer bolts then fill side cavities with rtv. correct ?

Congrats!! The first part of this thread was painful to read, in part because I've had a similar problem, many attempts to fix, and got it down to a very limited drip, but never perfect. Next time the pan comes off, it will get fixed like you described.

That is correct. J.Rob

thank you ! i'm glad to see , finally, a GOOD fix for this very common problem. i'm sorry it took you an inordinate amount of time, grief, and expense to sort this out. thumbs up to you !

Great job on the fix. This post should be saved in the archives.

When "dry fitting" everything, you will be able to "feel" as well as see when it fits right, with no influence on the seal. Like I said, you will probably have to drill the retainer holes bigger, but that doesn't matter. Once the dry fit is good, the retainer will continually return to the "right" place when you drop it in. So for final install, put a little RTV on the bottom and you can also fill the side channels as well..........then drop it in, bolt it down.

I am actually surprised this seems to be a "new" method for so many. This has been such a problem for BBM over the years, I just assumed everybody knew this already..........LOL!!!

Seems every builder knows you rotate the seal ends on Chevy's and don't glue them in. I just applied the same theory to the Mopar and assumed everyone else did the same.......

Hi Jesse,

Denis is very happy with the attention to detail on your work and looking forward to running his new RAMM machined Stealth's.

They're bolted on but he ran into some pushrod clearance issues so I brought him my die grinder and a carbide to open up the pushrod holes. He's running Crane ductile iron 1.5 rockers with 3/8 pushrods. A 5/16 pushrod would have been no problemo

I'll keep you up to date on our progress



Ron

I have been having to do lots of extra grinding on Sidewinders for 3/8ths just depending on what rocker is used so I went to 5/16ths and it makes life EASIER--Smith Brothers has assured me that at 9 inch length range ( typical 440) that a 5/16th .080 wall is good to 700 open so more than covers any street application --they make .120 wall for folks that can't sleep at night--I would never do it in race application with big roller but that is not what they are all about anyway

I am happy you got this fixed--I am going to try it on my next build--Thing is I just can't get past the fact that we built way over 100 BB Mopars over the years and NEVER a leak then all of a sudden last few years whammo! I believe that it is because of inferior offshore produced seals--I put so many together so many ways with every kind of block, crank etc over the years with the good old Fel Pro then they changed that darn seal! We ( me , Todd M and 2 other well known builders in NC) swapped to the Superformance red seal--All 4 of us went a long while with NO leaks--then..He swapped to a black seal ( I would guess Victor) and said NO DIFF--kept on charging big $$ for it --OK, I don't care as long as it works then...all 4 of us have had leak issues again! I am NOT happy with that outfit!
I have ordered all 3 part numbers of FelPro, a Mr Gasket, and Victor rep is sending samples to our shop next week, I also have a seal from a fresh new Sealed Power gasket set and have been looking for any older stock seals--I plan to lay them all out, study them, measure them and see what is going on.
I ask every engine shop manager I see what they do and keep notes--I was surprised last week when big reman shop told me about a string of trouble they had and when it was finally fixed they found that the lube a white lithium grease type they had been using was the culprit--Fel Pro said wrong lube is #1 problem so what the heck is the correct lube??? I now use OIL only--had always just used assem lube like the red or some STP/assem lube mix I keep in an oil can etc I have never used a grease type product.
I really appreciate the contributions to this thread by the many skilled dedicated builders but feel like there is STILL more than meets the eye here and that seal quality or lack of is a big part of it--
Like everything else in this USA --sourced from cheapo place so that corps make $$ NO care at all about us in the field
Just my two cents

My engine builder order every seal imaginable.
They all looked the same. Must be the same mold now for every manufacturer. If you find a different variant,pass it on.

Ramm, what exact rear main seal did you end up using? I know you said, "Black one."

Just used the ones that come in the FelPro RACE 2716 set. Nothing special and they are made by National Seal& Bearing. It was a shame to waste the FelPro "good" red ones #2947 that the customer supplied me. I have mentally designed and have part #'s for a speedi-sleeve and 1 piece seal using a bolt on 2 piece billet aluminum housing. It would only work with aftermarket fully round crank flanges but I was getting desperate--lol. J.Rob

They are all the same, save for the material. I am only referencing the RED one here. Big deal--they may hold up better in a severe high heat situation but then you have other problems. Believe me I was fantasizing about machining another groove in the block and machining a dedicated retainer to double up the seals at one point. Scary thing is I was this close to doing it--'cuz I can. J.Rob

I've known Jesse for some time now and I can say this. He is an excellent machinist. The man can fab and hold tolerances. He can and has rebuilt just about everything that runs.
Oh and he is a Moparts nut. Lol
Your build would be in excellent hands. Matt

You don't happen to mean like this do you? Engine in the car and as I was torquing retainer pan studs,,,,instead of usual bolts,,,,felt a rapid loss of torque as though had stripped out aluminum retainer thread.

Milodon RR pan, ARP studs for main caps.

A bit of grinding with Dremel and all was well.

As an aside for OP, your rear pan bolts that go into retainer are required to be shorter than the other 18 pan bolts if you are using the slightly longer than stock pan bolts such as supplied in after market kits such as Mr. Gasket. They send you 20 bolts all the same length all slightly longer than stock,,,,,used at retainer they will bottom out before pan is tightly sealed giving appearance of a rear main leak.

1974 Motor Repair manual discusses this in section on replacing big block mopar oil pan. There also is a mopar factory directive that discusses this.

With engine in car this is not obvious, but with engine mounted on an engine stand at dyno this may not fool you. OP did say he had examined closely with a flashlight with engine running and that indication is that his issue is not pan leak however. This is how I discovered my problem with engine running in car. Mr. Gasket pan bolts bottoming were bottoming in retainer before pan was properly cinched up. Hence now, my use of studs.

Likely with OP as he has we'll investigated, not his issue,,,just a heads up for others who may be experiencing mysterious rear main leaks or what appear to be so.

I have posted a couple of other threads on this forum discussing my own journey and twilight zone adventure with confounding rear main oil leaks. .

Hopefully the peanut gallery will contain themselves and refrain from sniping at this post,,,,a private request that a couple of forum gentlemen might understand.

Couple more photos of fix for weak pan flange on Milodon pan. Pan will not withstand suggested 15 ft pound torque without flange dimpling when used with some gasket materials.

Not trying to beat a dead horse but....Just so I'm clear, you don't use the side seals at all with this method? Only RTV?

And by the way Thank You to All for this post it is very timely for me.

crabman173, before you go attack my products, character, business and livelihood on an open web forum get your facts right! I never relayed ANY facts directly to you.

I did not “swap” to a black seal. Both the “black” Polyacrylate and the “orange” Viton seals have been discontinued. We have depleted our inventory of the Viton seal and have a limited inventory of the Polyacrylate seals available at this time.

No it is NOT a Victor seal.

The ONLY difference between the “black” Polyacrylate seal and the “orange” Viton seal we supply is the rubber compound, PERIOD!

So far as your claim to us still charging BIG $$ for the “black” Polyacrylate seal is a flat out lie. Without quoting prices I can honestly state our Polyacrylate seal sells for 40% LESS than it’s Viton counterpart. You do NOT purchase directly from Superformance Products therefore what you pay is between you and your supplier. I however call BS on your claim.

You’re not happy with my outfit? Well I’m not too thrilled with your comments.

Just clearing the air here. Same mold cavity number.

Correct........"driving" those side seals in can move the retainer........because as you know, you can't fully tighten the retainer and THEN get those seals in, you have to do it all together. So after it "fits" right, fill the channels with RTV, just a bit on the bottom...NOT a lot and drop the retainer in, tighten it down, clean off excess. Usually at this point, I will take a tube of RTV and use the white tube that comes with them, with just a bit cut off the end to make a small bead. Then put a small bead down each side and across the bottom, to make SURE there is no opening in the RTV seal

Monte

Hope this clears up any unwarranted misconception of our products.

Leaks cause frustration
Frustration clouds judgement
Public apology applied here and now Hope you will accept

Common factor of leaks with blacks, none with the other across number of shops / same time line-- is also a fact---frustration still weighs heavy

Develop a dependable new seal USA made that works and the world will beat a path to your door brother and price will not be an issue at all .

So three years later is there still a better seal in the orange versus black color ?



My newly rebuilt 432 Stroker 440 Source has a small leak and its definetly in this area

Valve Covers and Oil Pressure Sender perfect

I am still debating on if it was the actual seal , or those side o rings in the Mancini Retainer

It wasn't leaking prior to the rebuild this past fall , I offset the black fel pro seal at 6 and 12 and used black rtv on those side o rings on the Mancini Retainer for a few years and it was spotless

Only difference this time around is I don't know what black seal my engine builder used and the 440 Source crank is polished smooth versus the old factory crank that I took apart that was knurled in that seal area

Block was hot tanked prior to rebuild also , and I had a snap on borescope inbetween the engine and transmission double checking the cam plugs etc after engine was shut down looking for leaks

Had my engine builder offset the seals
at 6 and 12 , but he didn't use any rtv on those side o rings

Also on Hughes website they talk about Locktite 518 gluing the seal halves together where they contact


Just debating on these side o rings , black rtv or this anaerobic 518 gasket maker and the actual best seal before I attempt it again this weekend

You can use fluorescent die added to the oil and a black light to pinpoint the source of leak. May be worth it prior to a tear down.

To late

Already ripped apart and everything cleaned up

Was just debating on what seal , if anything has changed in these seal manufactures as of late

And these black o ring side seals if I should still use or just rtv or anaerobic gasket maker

I really think Monte was correct with his diagnosis of the seal retainer not fitting the block perfectly. This is something that MUST be perfect or is will not seal no matter what seal you have installed. Enlarging the holes will let the seal move to where it wants to be in relation to the crank journal center line.
This will be the way I do it next time if I ever have my engine apart again. It has a very slight leak there right now but nothing I'm worried about because it's maybe a teaspoon a month on the floor.
Gus

Are you using stock main cap bolts or studs now?
I use a adhesive silicone(it must have adhesive on the label ) to stop leaks on the main seals on BB by filling in the sides of the cap between the block and seal holder, both sides facing the flex plate, flywheel and also on the bottom, top of the seal holder, touching the block
I use a flat thin putty knife or small flat thin blade screw driver to force it into the hollow spots all the way all the way around the seal holder, take your time to get it correct
I also use a tiny dab on the seal half ends where they butt up against each other, I don't stagger them either I use a little tiny bit on the cap to the block surface also, not a bunch
I can't remember the last time I had a rear main seal leak, probably over 40 motors ago I can't say the same thing about the rear cam plug I seal them up now also with the adhesive silicone after they are installed all the way into the stop groove step
IHTHs

Hey bee1971, what was outcome with your seal and retainer?

I was doing same, and bought Mancini retainer kit with the 4 o-ring side seals. Dry fitting it I checked the gap between retainer o-rings and block. The o-rings dont even touch the block. .003" feeler gauge slides in between without any drag. The o-ring grooves seem too deep to me.

I think I will try directions as per post above - to fill the side seal with RTV. I don't know if I can fill that small o-ring groove all way toward cam from the bottom.

Also, Doing this with engine in the car,I don't see anyway to RTV the retainer once it is assembled. Maybe need to slide the trans back??

http://www.hemihaines.com/build-a-late-model-hemi.html

I viewed this step-by-step build on HemiHaines website and noticed how he put the main seal together. Looks pretty strait forward and allot of good pointers.

Orange/Brown Fel Pro Viton Seal

Permatex Black Rtv down the sides of those O-rings
Still used the O-rings , but also black rtv

Yes on those O-rings - The design or concept looks great but the O-ring itself needs to change , as in a little wider/thicker better material - I couldn't come up with anything else to use but they just don't fit properly in those grooves , way to loose ?

I knew where the retainer needed to bee seated/fitted prior to the installation as the marks where still there from when I mocked it up before the crank got dropped in

Seal halves at 6 - 12

Anyways its definitely not a seal issue , but rather those side O-rings and there fit seems to bee the culprit

So far so good