[craigs69]

Well, I finally got the seal installed into my engine last night. I let it sit overnight to allow the gasket sealer to cure and added oil to it this morning. It was put up on my cherry picker and stood on it's end while I held my breath. About 3 minutes passed and everything was dry. I walked away for about 30 seconds, and when I got back, the dripping had started. After a closer look, I could see that the oil was definitely coming out around the seal. It took about 2 minutes to get a 3" puddle on the floor. I am about ready to pull my hair out.

When I was installing the seal, it was necessary to remove the main caps and lift the crank about .06" as the seal would not slide around the crank with it sitting in the main journals. I did have to trim the ends of the seal .025" to get the proper crush, so maybe they weren't as square as they should have been? I did put a light smear of gasket sealer on the ends and across the parting line of the rear main, so that shouldn't have been the problem. I am at a loss. There are too many success stories out there for me to believe that the seal itself is the problem, so I am guessing that I messed up somewhere.

At this point, the engine has held me up for about 3 weeks and I have a lot of work to do on the rest of the car. I really have no interest in tearing this thing apart again, so now I am going to try to find a good Pontiac guy to take the engine to. Does anyone know of anyone within a few hours of Rhinelander Wisconsin?

[lust4speed]

Sorry to hear of you continuing problem. Since my post above I just did another friends 455 engine because of oil leaks. I wasn't happy on the limited distance when the crank was pushed up so I removed the rod caps and tapped the pistons down (up?) until they were touching the heads. Then the crank came out with no problem. It helps to have a second set of hands when re-installing the crank. Basically two of the rods will have to be lifted up and connected to the crank before it will drop back in.

The instructions say to not apply any sealant on the ends of the rope seal, but doing so wouldn't make things leak. I've taken quite a few main caps off where the seal ends were glued together and it didn't seem to hurt anything. Just best not to do it.

If the crank isn't in the way, you can properly seat the seal in the groove and then roll it in with a socket. After it has been fully pushed down into the groove as far as it can go, then you can trim the ends. Very easy with a graphite rope seal, somewhat of a pain with the stock rope seal. Seal shoud protrude slightly from the block and cap (about .020" or so), and be pushed to its center so no strands can get between the cap and the block. Trapping strands will keep the cap from seating and not only cause leaking, but slightly opens up bearing clearance at the rear. This will not only cause a slight loss of oil pressure, but also really increase the volume of oil squirting out towards the rear seal. Normally the slinger on the crank handles the oil flow nicely, but all that oil being in the area won't help the integrity of the seal.

[Wade Congdon]

Craig,

I know you did a good job installing this seal because we spokeabout it seveal time while you were doing it. I have to refer yo back to my earlier post.

"Everyone keep in mind that for the lip seal the "tip" test is not the final say in leakage. We have seen many engines drip on the tip test and not leak under use. This is because oil can migrate through the serrations in a static situation. The oil slinger and angle of the serrations fling oil away from the seal while running. In addition, the lip seal has smaller helical lips on the primary lip that actually "screw" the oil back into the engine while it is running. In the 2009 seal revision we made these less prominent to help the seal in a static situation, but bottom line is an engine can leak in tip test conditions and be leak free in real life conditions."

The "tip" test is not a valid test for a lip seal unless the crank is smooth. You will not find an engine builder that will take the care that you did when you installed this seal. I would bet that this engine will be leak free under running conditions.

[craigs69]

Wade,

Thank you for reminding me of your earlier post. Taking that into consideration as well as goat2789's post about his engine leaking while installing it but not while it is running, I went ahead and put the engine and transmission back in. The leak on mine was uniformly seeping around the entire diameter of the crankshaft, further reinforcing the theory about the serrations on the crank. If it had been a bad installation job, I would have expected to see the leak more confined to the parting line. I am hoping to fire this thing up sometime in the next week or two, so I will definitely report back when that happens.

[craigs69]

After many setbacks with aftermarket parts not fitting properly and "direct fit" radiators that didn't fit, I was finally able to start the car today. I ran it for about 10 minutes and didn't notice any dripping. I shut the car off for a bit to tighten a leaking radiator hose and started it again, bringing the RPM's up a little higher this time. I shut the car off and looked underneath to find a quarter sized oil puddle right under the torque converter. I crawled under the car to see if I could identify the source of the leak and sure enough....... it was coming from the rear seal.

I have decided that at this point, I am going to finish putting the car back together and drive it with the leaky seal for the summer. If I pull the engine again, I am certain that I will not have it back together soon enough to drive before it's time to put it away for winter. That is not an option for me as I am going through withdrawls already. All I have left to do is hang the front end sheet metal and put in the interior, so I am hoping to be driving it by the end of July.

[Formulas]

The non rope seals rely on factory block machining to be almost perfect. And they from reports are not all perfect and didnt have to be perfect with the stock configuration rope seal
I am running the improved rope seal in one car for near 8 years no drips from engine, Tightest engine i have ever done with the rope seal and viton valve seals combined

[lust4speed]

Originally Posted by craigs69

...I have decided that at this point, I am going to finish putting the car back together and drive it with the leaky seal for the summer...

Excellent plan. I would too.

[Wade Congdon]

Craig,

If it is pushing oil only at RPM I would definitley look at reducing crankcase pressure by venting to the air cleaner or another method.

[craigs69]

Thanks for the tip Wade. I hadn't thought about crankcase pressure and the air cleaner was not on the engine, therefore the breather tube was not connected. It is on the engine now, so after I fix my leaky thermostat housing, I will try again tonight. Hopefully that will help the problem. Regardless of the outcome, my wife made it clear to me this morning that I wasn't going to pull the engine again this year. She has been really patient with me during this project and I really don't care to push it.

[craigs69]

I now have valve cover tube connected to the air filter and I'm pulling 10-11" of vacuum at idle and around 14" at about 3,500 RPM. I'm guessing at the RPM's because I have a hood tach and the hood isn't on yet. It is still dripping a puddle the size of a quarter after about 15-20 minutes of running. It seems to drip more at higher RPM's , so I stuffed my vacuum gauge hose in my dipstick tube. At idle, I am showing 1" of vacuum and at about 3,500 RPM I show zero. I guess at this point I can conclude that the rear seal will have to be swapped out again. I gave much consideration to a vacuum pump, but it seems like a very expensive band aid. The motor really doesn't need it as it is just a 500557 block with dished pistons, 6X-4 heads, a Perforer intake and WAY too much cam. It runs remarkably well for such a bad combination of parts and it does have a 10" converter to keep it idling in gear. I was planning to put a stroker rotating assembly in it next time I pull it down and send the heads out for work, but I'm thinking that I will maybe go crate motor when the budget allows.

[NeighborsComplaint]

Sorry to hear about the seal failure. I went back to rope seal and mine is dry as a bone. The last seal I installed was a Cadillac neoprene seal before the BOP neoprene was in full production.

I followed Jim Taylor's directions to a T ... radial cuts in the seal grooves, .020" interference above the block, seal lips facing the front, top half bedded in silicone and tyhe lips lubed with petroleum jelly, bottom half dry, leave overnight, remove cap and set bottom(cap) half with silicone and petroleum jelly on the lips, silcone dot the ends of the seal along with the cap/block machined faces, leave overnight ... hell I even left it for a week to dry! I made sure the silicone bead was perfect with no excess goop, the seal grooves were perfectly cleaned, etc.

It leaked so bad the oil would flow across the oil pan rails and would leave an outline of the oil pan wherever I parked. On the road the oil mist would accumulate on my rear bumper.

I figured the seal must have spun but the shop who took it apart said the seal was still perfect, it just didn't grip the crank tight enough to seal.

I put in a Best Graphite seal this time and knock on wood, all is good.

[craigs69]

Today was the big day. After months of setbacks, I finally took the car for it's first post restoration drive. The weather is looking nice for tomorrow, so I was hoping to take the car for a nice drive, but the rear seal seems to be leaking pretty bad. I don't know if I want to take the chance of slobbering up the underneath of the car, so I may call it off. I will be pulling the motor again over the winter and replacing the main seal with a graphite rope. I have considered trying another BOP viton seal, because I know that the design is superior to the rope, however, my application was not optimum for the BOP seal. I changed the seal with the crank in the motor, so I was not able to use an indicator to check the concentricity between the seal diameter and the bearing bore. I did however probe the main cap on a CMM and found the seal diameter to be out .0075" from the bearing bore. The instructions for the seal state that there should be no more than .005". I also was at the low end of the tolerance when you measure the distance that the seal is sticking up from the parting line, so I am not 100 percent certain that there was enough crush when I bolted the main cap back on. With all things considered, I will probably give the BOP seal another shot in my next motor, but this one is getting a rope. At least I have all winter to get it done.

[GTOLou]

Originally Posted by craigs69

Today was the big day. After months of setbacks, I finally took the car for it's first post restoration drive. The weather is looking nice for tomorrow, so I was hoping to take the car for a nice drive, but the rear seal seems to be leaking pretty bad. I don't know if I want to take the chance of slobbering up the underneath of the car, so I may call it off. I will be pulling the motor again over the winter and replacing the main seal with a graphite rope. I have considered trying another BOP viton seal, because I know that the design is superior to the rope, however, my application was not optimum for the BOP seal. I changed the seal with the crank in the motor, so I was not able to use an indicator to check the concentricity between the seal diameter and the bearing bore. I did however probe the main cap on a CMM and found the seal diameter to be out .0075" from the bearing bore. The instructions for the seal state that there should be no more than .005". I also was at the low end of the tolerance when you measure the distance that the seal is sticking up from the parting line, so I am not 100 percent certain that there was enough crush when I bolted the main cap back on. With all things considered, I will probably give the BOP seal another shot in my next motor, but this one is getting a rope. At least I have all winter to get it done.

Hang in there Craig - it is a labor of love no doubt. One of the "good" things about messing with old cars is that when you get frustrated, just leave it the hell alone for a week or so. Its not like a pet that has to be feed, etc...lol.

I "like" the BOP seal, but in my mind it is less forgiving than the graphite seal. The graphite seal has a bit or parasitic drag, but dang it works. Someone else mentioned that the BOP seal is better in a 400 w/ smaller mains. Maybe so. I start w/ the BOP because I've got a test stand and can run the motor first and I wouldn't be ready to shoot someone if it leaks! Watch the rear of the oil pan as that is a source of pesky leaks as well.

I know what your saying about "restored" cars. There is a culture of folks out there that do a crappy job and then call it restored. I just bought a "restored" 76 455 TA from a guy who bought it freshly restored a few years earlier - he lost 5000 on it and I paid damn good money anyway (minus the 5000 he lost). I swear the carb had some overspray around the base of it where the motor was painted with the carb on.

Anyway - hang in there and good luck. This forum is full of folks (like me) who've made plenty of mistakes and will likely continue to from time to time.

[2002Z4CSS]

I used to work in a Olds dealer and have installed 100's of rope rear main seals. There is a special tool you can get to replace the upper half of the rope seal without loosening up the crankshaft.

[HWYSTR455]

Originally Posted by 2002Z4CSS

I used to work in a Olds dealer and have installed 100's of rope rear main seals. There is a special tool you can get to replace the upper half of the rope seal without loosening up the crankshaft.

I think that tool used to be called a 'sneaky pete'....

.

[craigs69]

Originally Posted by 2002Z4CSS

I used to work in a Olds dealer and have installed 100's of rope rear main seals. There is a special tool you can get to replace the upper half of the rope seal without loosening up the crankshaft.

How do you trim the ends of the rope with the crankshaft in and not scratch the crankshaft?

[tstroud]

Oops, didn't mean to post. Stupid iPad.

[dataway]

Jeez brother, you made me read that whole freakin thread again

[4zpeed]

Originally Posted by dataway

Jeez brother, you made me read that whole freakin thread again

Well I hadn't read it so it's all good

Um, er... except for that nasty leak, hope ya got that fixed Craig. Freaken ebayer's.


Frank

[craigs69]

Originally Posted by 4zpeed

Well I hadn't read it so it's all good

Um, er... except for that nasty leak, hope ya got that fixed Craig. Freaken ebayer's.


Frank

I am happy to say that the leak has been remedied. The 400 that was in the car at the beginning of this thread is long gone and replaced with a new 469. Unfortunately, the saga continued with the new engine and was finally brought to closure with the installation of a GZ vacuum pump. No more leaks anywhere since!