[grandam1979]

Well it might have been the pictures sometimes they can be deceiving it just looked wide to me then if you left extra for compression when the cap is installed was my thought. If it was to tight it probably got hot and you will be able to determine that when you look at it. Again that’s just my thoughts from 2000 miles away so take it for what it’s worth.

[Dragncar]

What b-man said.
Never heard of a BOP one piece wadding up like that.
Now, if the OP finds his crank is not bent and still dead set on using a old fashioned rope seal I have a actual PMD asbestos seal given to me by a PY member all the way in the UK.
I have been saving it for awhile but I will pay it forward as was done to me.
Just let me know.
Its tough to see a member go through all this on such a nice car and nice engine.

[lust4speed]

My ordeal with the Best Teflon/graphite seal was way back and the seal had only been out for a few months. This was before they added pins to the kit or suggested sealant. I always had good luck with the original Pontiac rope seal by pre-loading additional seal into the groove by pushing additional seal into the groove from the center section out to the ends, and then rolling the now fatter seal down in the groove. Worked with the original asbestos rope but a disaster with the Teflon. Where the original rope simply burnished into a nice taunt fit, that first Teflon seal melted and dripped out on the ground. Not a life experience I needed. After that I learned that dropping the seal in the groove loose and rolling it in was sufficient and no more melting.

It's been quite awhile since I've used any rope seal and use the BOP Viton seals. I don't mind the 2-piece, but love the one piece seal. Even used the one piece seal on an engine the machine shop line bored the crank centerline .027" higher. Wade guided us through getting the one piece seal to fit on a Saturday afternoon which was way beyond the call of duty. By the time the Viton seal was sanded down and fitted the steel reinforcement ring was shadowing through. It's been a year and a half and despite the major alteration needed to get the seal centered to the crank, the rear main is leak free.

[Gach]

I don’t get all this, I’ve used the Best Teflon/graphite, on my IA block twice and never had and issue, plus a number of other block builds never a issue. What an I doing right.

[HWYSTR455]

Going back and looking at the previous attempts, it looks like there is too much seal above the actual groove.

If you look at the one pic, you can see it got squeezed out past the groove and out to the sides.

You need to roll the socket back & forth so it spreads the seal 'longer' and trim once done.

With the way those seals look, it had to have been difficult to turn the engine over by hand, or at least more than it should have.

Once you get it all in there, after it's torqued down (no parting surfaces w RTV), take the cap back off and look at it. Then put a little RTV on the parting line of seal and reinstall.

I'm pretty certain the groove should be dry and no RTV. There should only be a small amount at the seal parting lines.

.

[HWYSTR455]

Simpler terms, it was too much seal used in the groove.


.

[Sirrotica]

FWIW, Best has some rear main seal helpful hints on their site, this may be helpful for another attempt, plus future persons using this for a reference.

Link to Best : https://bestgasket.com/fanfare/

I've actually never used one of their main seals, only the asbestos type, and the later fiberglass type. I have used graphite seals on a low speed application, those seals are made on a hemp type rope, not teflon cord. I can see where if the seal was packed too tight,it would expand from friction, and engine heat. Having very little oil from the crankcase, and the lube that was applied while doing the original install finally wore out, the teflon would start melting down. Best provides a spacer to trim the ends .015 above the block, so there is some crush on the ends when the parts are assembled.

Fiberglass, and asbestos doesn't melt as a synthetic does, so packing either of these tightly could only result in the seal wearing, or spinning in the groove machined in the block. Having worked for years on many GM engines that also used rope style seals, I have seen a few OEM seals actually spin inside of the groove. Of course once they spin material gets shaven off, and they start leaking severly. This problem caiused the early demise of quite a few GM 5.7 diesels as they quickly ran out of oil, further adding to their horrible track record in reliability.

By nature of their design the crancase pressure is higher than gas engines, making it just as hard to seal, if not even harder than the Pontiac Stratostreak engines. When working as a line mechanic in a buick dealership in the early 80s, I got more than my fair share of 5.7 diesel rear main seals..............

The whole operation paid less than 2 hours flat rate, and if it leaked you got to do it again for free. It was done with the engine in the chassis, and you dropped the crank by loosening all the main bearings, letting the crank hang in the block. You formed the seal inside of the rear main cap, trimmed it, then transferred it into the block groove. Talk about a money losing job, it was about 50/50 shot whether it sealed on the first try.

[Verdoro 68]

Originally Posted by HWYSTR455

Simpler terms, it was too much seal used in the groove.

I'm thinking this is the case. Too much seal is the only way I could see it wadding up like it did. That said, the pic above is after the seal was cut but before I pushed the seal level with the block/cap. I didn't pick up on any discernible extra drag when I had it assembled, but maybe I don't know what to look for. I'll still get the crank checked to be sure it's straight.

I may revisit the BOP one piece after these two rope debacles. Wish I was a little closer to b-man and Mick, I could use some help on this one.

[Gach]

I wish I’d had save a picture of the old one still in the block and cap, before I replaced it with the new one. Anyway it was flush with the cap and flush in the block. It would be nice have a picture of one in block and cap that had no issues. A good Visual would help feature installs. I press mine in first then cut them after there press in. I had blown a head gasket getting antifreeze every where, trying use copper head gaskets that was supposed to have built in O’rings.

[grandam1979]

If you go to a one piece don’t install it alone it takes two people.

[b-man]

Originally Posted by grandam1979

If you go to a one piece don’t install it alone it takes two people.

Sometimes……sometimes not.

I know a guy……

I guess you missed my previous post with pictures showing how it was done.

[Gach]

Originally Posted by grandam1979

If you go to a one piece don’t install it alone it takes two people.

I just can’t visualize trying to install that one piece, even with a helper unless the helper had more experience then myself. But hey it works for some. Not for me.

[Verdoro 68]

Here's the carnage.

I had to have overpacked it. I just don't know how it lasted so long only to completely self destruct so quickly. It sent fine particles all over but I think the filter caught a bulk of the mess, at least judging by what I drained out of it. Some fine trash in the pan and a few bigger pieces in the oil pump pick up. Most of the seal fragments appear to have exited the block.

Main bearings look fair - not brand new, but not trashed. Crank seems ok as far as any serious scoring or damage. I haven't looked at the rods yet. I'm fortunate this happened so close to home, but man, what a mess.

So I guess I need to figure out how to get this cleaned up.

[Verdoro 68]

The oil that came out of the filter

The rest of the oil I drained out of the engine did not look like this.



Bearings and crank. These don't look horrible to me, but don't look awesome. Clearly there was some trash in the oil. Wondering if this calls for a crank polishing and new bearings or if you all would bolt it back together as is. There's nothing I could catch with a fingernail. Despite all of this, the oil pressure was great.

[Dragncar]

BOP and be done with it.

[Verdoro 68]

Originally Posted by Dragncar

BOP and be done with it.

One piece seal arrives Friday.

[Gach]

Originally Posted by Verdoro 68

One piece seal arrives Friday.

Don’t blame you after what you’ve been through. Nightmare

[Verdoro 68]

A nightmare of my own making. Ironically, I started with the one piece, but it leaked on the stand so I gave up. I thought the Best Seal would be an easier install since I’m working on this without help.

After further reading, I discovered that I didn’t fit the one piece correctly so this mess could have been avoided if I read the instructions more carefully. Lesson learned to go slowly, read, re-read and re-re-read the instructions.

[Gach]

Lesson learned.

[Dragncar]

Originally Posted by Verdoro 68

A nightmare of my own making. Ironically, I started with the one piece, but it leaked on the stand so I gave up. I thought the Best Seal would be an easier install since I’m working on this without help.

After further reading, I discovered that I didn’t fit the one piece correctly so this mess could have been avoided if I read the instructions more carefully. Lesson learned to go slowly, read, re-read and re-re-read the instructions.

I remember all that when you did the tip test.

It took me twice on the BOP one piece. First one I trimmed the ends. mistake.
Its a pain to fit right. Tq it down, look for it to be centered, wrinkles in the lip.
Sand, re do, check over and over.
I have not even tested mine. But I have a V pump and its hard to have leaks with them. At least that is what I have been told.
Wade is great to deal with. Pontiac treasure.