Rear main seal woes part 2

[defiance]

first part was here:
http://www.dodgecharger.com/forum/index.php/topic,47911.0.html

Summary of what was done in the prior thread:
-take .010" off the mating surfaces per 440source recommendation.  No luck.

-Use play-doh to get good idea what the clearance is.  crank-to-bottom of channel measurements:
--block sides -.085" and .083" clearance
--cap sides -.093" clearance (pretty much dead equal)
--cap bottom - .102" clearance

Summary of work since then:
-Took engine back to machinist.  He said several things:
-- First, he said the knurling looks OK, and that even if it was bad it wouldn't cause a leak until the engine was spinning (by eating away the seal).  440source said basically the same thing (that knurl problems wouldn't show up until the motor turns enough to damage the seal)
-- second, he said the seal is only .090 thick (I haven't measured it myself), and that it needs .020 of compression, so I need to cut .030 more off it.  I thought he was crazy, but I let him cut .020 more anyway.  Still no seal.

-He tells me basically "I told you so" and wants to cut the cap more.  By my calculations, the bottom is now .082" clearance from the crank, which is closer than the block is, and we've already taken .030" off the seal cap, it's GOT to start losing round-ness somewhere in there.  Not to mention, this .020" compression needed sounds insane to me. 

So, now I'm getting another machinist.  The engine goes to the new guy today.  I've told him to look again at the knurl, cap, and seal. 


Meanwhile, do you guys have any other suggestions for me?  I've now taken this bottom end apart and reassembled it (which, with the girdle, windage tray, and pan, is quite an undertaking) 6 times (I think?), and I'm now heading to the second machinist.  Any advice on seals, caps, machinists, or psychiatrists is welcome.

[defiance]

anybody?  The new machinist is giving me the same story, so I guess I really do just need to take ANOTHER .020" off the caps? 

[RD]

man defiance.. i never thought this would be as much of a headache as it is already... i really am at a loss.. i would go with what the machinist said, but i would have him write a guarantee down or insure his work or something so that you dont keep throwing $$$$ at this with no solution.  i know its asking a bunch.. but maybe they may put their reputation where your money is and go for it.

[firefighter3931]

Defiance ;

Where exactly on the rear main is it leaking....on the retainer side or the block side ? Or both ?

I'm inclined to think that the retainer needs to be trimmed down some more. 


Ron

[defiance]

The leak *appears* dead center on the bottom of the retainer.  Since it's behind the flange I can't see into the gap to see if it's dripping down from another part of the seal and only coming out on the bottom, but I think that's pretty unlikely.  Which, again, lends credit to the machinists' diagnosis.  I'm just shocked that we've already taken off .030" and it still needs more!

Ah well, I guess the worst that can happen is the retainer gets messed up. PITA, but easily replaced if need be.  Just never heard of one needing .050" taken off it.  Guess I should stop doubting my machinists and let them do their job

[RD]

have you tried a different retainer altogether?  cant remember and too lazy to read through part 1.

[defiance]

No, but if this next step doesn't work, that's basically where my thoughts are going - if they've taken that much meat off the thing and it still won't seal, it can't be properly round (even if it was to start with..)

[defiance]

Maybe this is finally coming to a close.  Just to reiterate what's been done to the cap->

took .010" off (blind).

Took measurements - bottom of seal retainer groove to crank was .102" at the very bottom of the engine (worst spot).  I didn't measure the depth of the groove, but I'm pretty sure it was at least .040" or so, meaning total 'metal-to-metal' clearance was .062" or so.

first shop took .020" more off the cap.  Still didn't seal.  They said we "probably need another .020".  I took the engine to a different shop.

New shop claims they took the cap and a stock cap from a known working 440 and measured everything, and he was absolutely confident that the mating surfaces needed to be cut down .040" to be equal to a stock cap.

So, I say fine, if you're sure that's what it needs, do it.

They do it. 

It seals. Mostly.  Now it suddenly develops a leak at the *top* of the crank, in the block side, but it's a slow one, and the shop has been using the same seal the whole time, so he believes that the seal probably just got damaged one of the 2 billion or so times we've had it apart.  Sounds reasonable since every other time the top of the seal has been OK (and the first time I actually kept pressure on it for 3-4 minutes before I saw the leak, so I'm sure the top had gotten pressure too).

Now, on one hand, I simply cannot believe this.  This will total up to .070" taken off?  What cap needs nearly a tenth of an inch to seal up?  And furthermore, .060" of it was taken since I measured a total groove-to-crank clearance of .102", and I KNOW the groove depth was at least .040, so .060" off would leave metal-to-metal clearance of somewhere around NOTHING.  That CAN'T be right.  I just hate feeling like somebody had to have lied to me; the math says the cap should be metal to metal, and it's not.

On the other hand, who cares? If it fixes it, great!!  Just needed to vent a bit.

[RD]

my question is this now... are you going to have sealing issues when it comes to putting an oil pan gasket on that retainer?

[defiance]

my question is this now... are you going to have sealing issues when it comes to putting an oil pan gasket on that retainer?

In my case it's actually going to be against the girdle - which is less margin for error, really - but on the other hand, it's not a moving part, and shouldn't be under pressure, so filling in .070" with silicone would probably work..... I hope. 

I put it most of the way together again last night, letting the sealant cure, and will be trying to prime the system again tonight, so we'll see...

[firefighter3931]

I'm just curious about which seal retainer you're working with here....is this a stock retainer or an aftermarket piece ? I'm assuming that the block was line bored correct ?



Ron

[defiance]

It is a 440 source retainer.  The block was line bored by the first machine shop.  That shop had the retainer at the time of line boring, and they assembled the short block.  I had assumed they would have measured this in the first place, given that the line bore would alter the way it would fit, but they obviously didn't.  I spoke to 440 source early in the process and they indicated that it could possibly need slightly more than .010" but wasn't likely to need more.  I haven't checked back with them since.  If I believed the machinist I'd want to get back with 440source and discuss further, but I just don't know what the truth is about how much has really been cut.

Still, I don't care who did what wrong anymore, if I can just see it hold oil I'll be in love with the world.  t minus 3 hours to test

[defiance]

WOOOOOOO!  Man.  Never thought seeing something not leak would make me so happy.

Now I'm back to where I thought I was in August.  *almost* ready for the test stand

[firefighter3931]

Fantastic news ! 

WOOOOOOO!  Man.  Never thought seeing something not leak would make me so happy.

That's funny....good stuff there !



Ron

[RD]

WOOOOOOO!  Man.  Never thought seeing something not leak would make me so happy.

Now I'm back to where I thought I was in August.  *almost* ready for the test stand

awesome!!!!  glad you got her fixed.

[defiance]

*sigh*.
Spoke too soon.

I just had the shop testing with just the pan (no girdle or windage tray) because we'd taken it apart so many times I didn't want to go through the whole reassembly process unless I was sure it was going to work, so after getting a good result I pulled the pan and reinstalled all the stuf and put everything together, then tried priming again just to be sure ....... and it leaked again.  Bottom again this time.
The first time I only tried for about 2 minutes, this time I held it a little longer.  Didn't actually start leaking until about 2-1/2 to 3 minutes...  But once it started it was a continuous drip.

Man.  I'm just tired now.  I mean, I haven't even gotten really upset or anything yet, just ... tired.

I dunno.  I'm going to pull everything apart and pull the crank so I can clean up the block side of the seal gap tonight/tomorrow, send an email asking for suggestions to 440source, and start asking for recommendations in this area for a new machinist.  I know, I know - this is already two I've gone through, but both of them have told me they were certain that 'x' was the problem, done their fix, and failed to fix it.  They've also both wanted to do the measurements, do the machine work, then let me do the testing.  I'm hoping I can find someone who will actually make sure it's right.

I saw another thread about 440souce quality control, and I think it referenced this thread.  One thing I want to make sure is clear: at this point, I'm doubting the competence of my machinists, so I don't necessarily know if there's any prolem with the 440source parts at all.  Of course, that doesn't necessarily explain why it didn't seal to begin with, so who knows.  I'll see if 440source has any suggestions.

[Mick70RR]

In the first thread, I think turbobitt makes a good point about aftermarket rear seal caps. With a stock cap installed, any oil that gets past the main bearing is vented to the sump. The 440 Source cap look flush with the no. 5 main bearing cap so the oil has no where to go except past the oil seal. I'd try a stock end cap or have the 440 Source cap machined to give the oil somewhere to go.

[defiance]

Yeah, already looking for a used stock cap locally.  I missed that post, but this cap has been cut so much I figure it's way out of shape anyway, and figure with a stock one that comes from a formerly working engine, I'll know that it's not way off to start with.  That adds another reason...

[defiance]

Quick note: can confirm the shop's measurements were off and they cut too much - I can visibly see where the seal is "squished" more in the center. 

My belief right now is that despite the word of two local machinists actually looking at the thing AND the word of the guys at 440source, our own firefighter's synopsis is correct.   Last thread he said he figured it was the knurling, and that if I didn't fix it, I'd be fighting it from then on...

Well, now that I've got the cap off I can see several things.  First, I used too much silicone last time.  It spurted up behind the seal and went all the way up to the crank.  Second, since it did, I can see the imprint of the crank - and the knurling - in the silicone.  Meaning, I *KNOW* for a fact the seal was seated against the crank.  And yet, it still leaked?  Further, oil was visible on the crank directly under the seal.  with the seal against the crank and yet oil visible right there, it HAD to have been leaking through, and my thoughts are that wouldn't be possible without leaking through the 'gaps' in the knurling.

Does that make sense, or is the machinsts' and 440source's original assertion that knurling problems wouldn't leak in a 'still' crank correct?

Probably doesn't matter, either way it's going to a machine shop, I'm just trying to be a little more on top of things this time...

[idahogrumpy]

I just installed a main girdle on a 470 we are building. I had to remove material from the seal retainer where the rear main stud nuts came in contact with the main seal retainer. The rear main seal retainer was touching the nuts when being torqued down. No matter how much you cut from the bottom of the retainer at the parting line would the problem be corrected, it probably would have made the problem worse. You might take a close look at that, It did not touch until tightened and then only very little. Good luck Kyle 

[firefighter3931]

Maybe i missed it but does this crank still have the knurling intact ? If so, that would be the first thing i would look at correcting. My machinist allways removes it....no questions asked. I recently purchased a 4.5 stroke Eagle crank that was .010 under on the rod throws as a "blem" that had been reworked by Eagle themselves. Guess what...the knurling was gone ! 

I'm thinking the stock retainer is something worth trying. 

Fwiw, my buddy Kevin runs the stock retainer on his blown 440 with the BCR girdle system with no leaks. 



Ron

[defiance]

My belief right now is that despite the word of two local machinists actually looking at the thing AND the word of the guys at 440source, our own firefighter's synopsis is correct.   Last thread he said he figured it was the knurling, and that if I didn't fix it, I'd be fighting it from then on...

In retrospect maybe I should have known to reexamine the quality of my machinist when they didn't agree with you

[turbobitt]

In the first thread, I think turbobitt makes a good point about aftermarket rear seal caps. With a stock cap installed, any oil that gets past the main bearing is vented to the sump. The 440 Source cap look flush with the no. 5 main bearing cap so the oil has no where to go except past the oil seal. I'd try a stock end cap or have the 440 Source cap machined to give the oil somewhere to go.

Guys,

The oil slinger needs to properly vent/direct oil to the oil pan but some of these seal caps won't allow oil to do this and it results in oil pressurizing the seal. My Indy cap is much like the 440 source cap from what I've seen in the pictures and would think that it has the same issues. Also, the main bearing cap can interfear with the alignment with the seal retainer if it is close like mine was to the point that it was contacting it. The new rubber seals are only a tinny fraction of the area of a rope seal and both upper and lower half's need to be perfectly aligned with each other to seal. Installing the retainer with seals with the crank removed to make perfect alignment and then scribe across the top so that it can be assembled and aligned during final assembly.
I know I posted some recommendations on another thread but couldn't find it.

If the crank is in the block, and you are attempting to reseal the engine with it in the car, the only choice you really have is to offset the seals so that the seal will force an alignment between the retainer and block.

[turbobitt]

Found my earlier post, Thought I would throw this up again.

http://www.dodgecharger.com/forum/index.php/topic,47911.0.html

I have had leaking rear main seal and this is what I found.

1. The main studs often interfer with the seal cap. Make sure there is clearance between the top of the main studs and around the nut.

2. Some of these aftermarket caps are solid on the end facing the cap with the oil slinger clearance cut. The cap will mate flush with the main cap and not allow oil to drain from the slinger area. Oil pressurized from priming/running will overcome the seal and find its way on the floor if not allowed to vent. Note the open/profiled area in the factory seal retainer.

3 - If the crank was out of the engine, bolt the main cap and torque. Then bolt on the seal retainer with the seals and check alignment of the seal halfs. With the slop in the holes, it is possible for the halfs not to line up and sensitive with the rubber/neoprean knife edged seals. This is not an issue with a wide rope seal. With the seal cap slightly lose, you can line it up and scribe a line accross the top of the seal retainer and block to correctly assemble later with the crank in the block.

4 - 440 source cranks have a very aggressive knurle and may be part of the issue. May need to use a rope seal.

[defiance]

1- I've checked the clearance with the cap, nothing is interfering.  The retainer was REALLY close to bumping the cap at one point, but not quite touching. 

2- If I understand what you mean, every aftermarket cap I've ever seen is like that - Mancini, 440source, mopar performance, BCR.  Do you have a suggestion to fix it?  I'm still looking for a factory one, but if that's a flaw, it surprises me that all aftermarket cap mfg's make the same mistake ... Or am I misunderstanding?

3 - The 440source cap is apparently wider than oem - I can't really slide it back & forth a noticeable amount.  The seal halves do line up OK, though.

4 - Now that I've got the crank out and have a good look at the knurling, it's pretty harsh.  Would using a rope seal possibly overcome that problem?  If I can avoid having to cut out that knurling, I'd prefer that route...  But where can you find rope seals anymore?  Everywhere I'm looking sells the two-piece ones...

Thanks for all the advice, it's much appreciated!