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Rear main rope seal
https://www.slantsix.org/forum/viewtopic.php?t=55852		 Page 2 of 3
Author:  Charrlie_S [ Mon Sep 29, 2014 12:18 pm ]
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I found some NOS rope seals. If anyone is interested send a PM
Author:  Feather_Duster [ Mon Sep 29, 2014 8:45 pm ]
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PM sent
Author:  SlantSteve [ Tue Sep 30, 2014 2:02 am ]
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I would have loved to use one of those NOS rope seals but, I've just received my neoprene Felpro seal...ordered from the USA and delivered in 10 days,at 30% the cost of Penta$tar wanted. I'm still a little concerned about the idea of a lip style seal running on the knurled surface of the crank,but it obviously works OK....I hope!
Author:  Doctor Dodge [ Tue Sep 30, 2014 8:46 am ]
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The lip type seal can be used successfully IF you spend the time to install it correctly.
I had to make a special 'checking mandrel' that let's me inspect the installed seal for "concentricity" and good lip contact / compression.

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Sad to say that about 50% of the engines I check do not have well centred seals and need some "fussing" to get a good, uniform seal lip compression.

In some cases, (mostly aluminium SL6 engines) the alignment is so far off that I go right to a rope seal.

Once you confirm the seals location & even lip compression, mark the cap and seals to insure they go back in the same order & location. (It is easier then you think to install the lip seal "backwards in the cap.
Now polish the knurl on the crank as best you can and be sure to do a slight off-set, at the seals parting line when installing everything.

Use some sealer and be sure that oil can not make it's way up and around the bolts... that can be an over-looked "leak path".
DD

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Author:  SlantSteve [ Tue Sep 30, 2014 1:18 pm ]
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Thanks for those great tips! I installed mine yesterday, I installed the seal offset and made sure the bolts are well sealed... But I didn't make a mandrel to test seal contact, great idea! Got me thinking I should remove the crank and do it, knowing my luck mine will be one of those blocks that need tweaking. As a side note, this must have been the lowest compression slant ever made, even with 198 rods and 2.2 pistons it was still .040" down the hole when I mocked it up!
Author:  SlantSteve [ Wed Oct 01, 2014 2:36 pm ]
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I gave the seal a once over again today,I didn't pull the crank again,but I filled the seal cavity with light oil while the engine was inverted and then used some compressed air to do a static check,then left it sit for a while...no leaks! I know its only a static check but it gave me a little reassurance. I'm confident I fitted the seal the correct way,but like Doc said,it's very easy to fit the lower section back the front. Its now all buttoned up ready for paint and final assembly prior to fitting..all I need is time! Really looking forward to seeing how it runs,spent a lot of time blue printing ,all deck heights the same,all rockers same ratio,head ported,engnbldr valves and a cam grind the same as the 175hp Aussie Valiant Pacers,very mild but worked well,and 9/1 comp..will keep you all posted! Who knows,with the extra work on the head it may make a solid 185 hp which I would be happy with for the resto it's going into.
Author:  SlantSteve [ Mon Dec 01, 2014 11:55 pm ]
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Just as a follow up to anyone who is curious,I fired up my rebuilt slant yesterday ,it's fitted with a FelPro lip seal....no leaks,completely dry! Very happy with it. I'll post up a rundown of my build in the engine build matrix in the next day or so...it's got an Aussie Pacer spec grind, ( I think they were 175 HP) zero deck,I increased the diameter of the .180" deep piston dish to get 9.2/1...running more advance than old engine and I have yet to hear it ping! With the ported head I'm thinking it's making at least that,certainly feels good..Looks like a winner :D
Author:  Sam Powell [ Tue Dec 02, 2014 5:20 am ]
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The cross hatches on the crank are angled to draw oil back into the engine as it rotates. They also will wear neoprene seals. One theory is have the crank polished to remove the cross hatches. I did this on mine, and it still leaks a bit. Not enough to spot the floor,but enough to get the bell housing oily after a thousand miles. I do not remember if I offset the seal seams as Dan suggests. It has been many years and miles since I did this.

Sam
Author:  DadTruck [ Tue Dec 02, 2014 5:50 am ]
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Quote:
the crank polished to remove the cross hatches.
I have not worked with machining crankshafts since the 70's but back then there were specific guide lines that the tool path for the tooling used in the final machining work done at the rear seal area, the tool path is to run from the outside inward when the crankshaft turns in the normal direction. That results in the micro tool ridges running in a corkscrew fasion inwards.

That was verified peroidically by positioning a weighted thread across the main seal area of the crank, with the crank seting level in V blocks, turning the crank several revolutions in the normal direction, the weighted thread should travel inward...

the intent is to have the micro tool ridges working inward to pump oil at the seal interface in.
Author:  SlantSteve [ Tue Dec 02, 2014 11:34 am ]
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Quote:
They also will wear neoprene seals. One theory is have the crank polished to remove the cross hatches. I did this on mine, and it still leaks a bit.

Sam
From what I saw in the kit there is no instruction from Fel Pro to completely remove the oil slinger scroll markings on the crank....the material of the seal was a lot tougher than any normal one piece lip seal that I've ever fitted to a rear main...if the markings do wear the seal I would imagine there would be enough material transfer to eventually fill the slinger grooves anyways...Ive seen stroker cranks weep oil and these usually are smooth surfaces...like yours is now....I did polish the seal area as per Docs and FelPro instructions and offset the joins as Doc mentioned. Time will tell but I fell confident that if the scroll was an issue with this seal design the manufacturers would be requiring its removal.
Author:  '67 Dart 270 [ Tue Dec 02, 2014 9:44 pm ]
Post subject:  rope seal part number
The part number for the Mopar rope seal is 04397712

If you search ebay you can still find them. AAAMarine had them a few years back for cheap, but I don't think they sell them any longer.

The new rope seals, from what I've read, are not nearly as good as the old ones. The old ones have asbestos, but they work well. I have one in my slant and get only a slight film of oil on the rear cover over. I had used neoprene, it had a regular drip, but then again, I didn't install that one.

For the neoprene, the offset install method seems like a great idea, where the seal abutting ends don't line up with the cap/block seam (and a dab of silicone on the ends during installation).

briian
Author:  '67 Dart 270 [ Tue Dec 02, 2014 9:48 pm ]
Post subject:  here's a couple
http://www.ebay.com/itm/CHRYSLERDODGEPL ... 1b&vxp=mtr

But they want a fortune, I think I paid $5 at AAA Marine a few years back.

briian
Author:  '67 Dart 270 [ Sun Dec 07, 2014 9:50 pm ]
Post subject:  rear seal
It seems for such a vital part, and one so hard to get to after the engine is installed, they would have come up with a more robust sealing mechanism than that little neoprene deally. Why not something wider, with a couple of lips, for redundancy?

So, just for my curiosity, was the spiral knurling in the crank always done, even back in the rope seal era?

brian
Author:  nm9stheham [ Mon Dec 08, 2014 6:17 am ]
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My '62 has the knurling. (Just removed the original rope seal.)
Author:  SlantSteve [ Mon Dec 08, 2014 1:15 pm ]
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The scrolling is an essential part of the rope seal setup...if the area gets worn and the scrolls get smoothed out it usually makes the rope seals leak. The lip seals usually run on a smooth surface...but obviously the Fel pro lip seal is made to work with the scrolls....seems to be giving me zero issue so far.
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