EAGLE cast crank rear seal ???
 

I have a new EAGLE crank coming for my 455 build. In the description it states "2 piece rear main seal". The last Poncho i built (circa 1994) ..thats ALL THERE WAS...lol So in ordering the other stuff from BUTLER (they did not have 1 in stock) I see a 1 pc viton seal and also a 2 pc viton as well as the ANCIENT rope seal. I realize the surface of the oem crank ( for a rope seal) is serrated slightly.

What seal do I need for this crank? Surely it would be full smooth for a lip seal right?

The Eagle crankshafts also have the serrations. When we ordered the 467 stroker kit from Butler earlier this year, we made sure to have him polish the serrations so that it wouldn't give any problems using the 2-piece Tin Indian Viton seal that we used. He told me that it used to be a problem with the Eagle crankshaft years ago, the serrations were way too aggressive,, and they would eat the seal up, but he said nowdays there isn't normally a problem with them, but he offered to polish it for us anyway for an extra 25 bucks, so we opted to do that, because we figured 25 bucks is cheap compared to eating the seal up and all of the work that has to be done to correct it Lol.

As long as the crankshaft is smooth enough, any of the seals he offers will work great with it. We have used both the Viton 2-piece seals, as well as the 1-piece seal with great results.

cool thank you, I have not seen the crank yet but am trying to plan ahead for what "other stuff" I need to do.

The one piece is the way I would go!
Other then needing two people to drop the crank is it’s at least 50% less likely to leak then a 2 piece seal.

A fwiw, very unlikely they have changed but the Tin Indian rear main seal is not Viton material.

https://www.bopengineering.com/viton_compare.shtml



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We are happy to introduce our new and improved 3" Viton ® Pontiac Rear Main Seals as well as our 3.25" Viton ® Pontiac Rear Mains seals.

https://tinindianperformance.com/Pon...in%20Seals.htm

Viton material is not blue !

https://www.globaloring.com/oring-colors/


Viton seals: What are the differences in color? Green is the color of choice in Europe for color coding Viton, whereas brown is the color in the US.
Sometimes black.

Viton is a duPont trademark for a specific fluoroelastomer polymer (typically abbreviated as FPM) made with vinylidene fluoride-hexafluoropropylene copolymer - the so-called Viton A resin. Magnesium oxide (MgO) is added as a proton (acid) acceptor to react with the small amount of HF that results from polymerization of the resin. MgO is brown, thus an excess of MgO causes the finished product to be brown unless sufficient carbon black is added as a colorant

http://franklin.chem.colostate.edu/glassguy/viton.html




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Serrations, use the Best Seal.

Those burn up and melt clogging the oil pick up. Every option has issues

The real answer is to tell Eagle to offer a non-serrated crank as an option for those who can use lip seals instead of rope seals.

But my faith in Eagle is pretty low.

Never heard of any rope seal burnt or melting.

https://bestgasket.com/rear-main-seals/#pontiac

I have had the Best seal melt. probably on an over serrated crank.

Anyone polish that journal and use a Best ? The Eagle I had the serrations were very light.
I have a PMD asbestos seal that can be used on that crank, gave it to my brother.

The new rope seals, when cut clean, and installed right work well.
On 455 blocks made in 75 and 76 you can find huge discrepancies in the rough cast area where the original rope seal sits. This can make indexing a new style seal impossible. Most of these cast SEAL areas are NOT concentric with the crank. My machine shop owner and I did a AERA bulletin on this. 75 and 76 blocks ONLY.

I've known about the non-concentric seal grooves in Pontiac engines for years--read about it most-likely on this very forum.

I did not realize it was limited to 455 only, and '75--'76 only. I thought it was Pontiac engines in general--some were made concentric enough for a lip seal, and some weren't.

Glad to know it's more limited than what I previously believed.

In a 462 of mine I built in 2004 stock crank turned at Velasco's I used the Best Seal Rope

Lots of California miles today parked on concrete in
My pole barn in WV. not one drop after being there 3 years

So easy a Cave Man can do it

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I haven't seen extreme serrations in Eagle cranks for the last couple years, but the last crank received about two weeks ago had serrations just a little iffy. Only took a little polishing of emery cloth to knock the edges down.

When the Teflon/Graphite seal first came out I installed it the same as I installed the old rope seals and was rewarded with shards of melted seal. Trick with the TG seal is to not pack it in place and basically lay it in position. No problems once we learned to not pack it, but still much prefer the BOP seals.

We had a block machined for 4-bolt billet caps and the machine shop* ended up raising the main journal centerline .027". That necessitated the use of a gear drive assembly for the cam and presented a sticky problem for a rear main seal. My son-in-law wanted to use a BOP one piece seal and spent considerable time on the phone to Wade. With his guidance we ended up shaving the exterior of the one-piece to where the seal centered on the crank centerline. Scary process but it is sealed up and no leaks after a year.

Here's what I've found on club engines we have worked on. Just my experience and your results may vary:

Original rope seal with asbestos - lasts many years if installed correctly
New rope seal supplied in gasket kits - drip free for about a year
Teflon/Graphite seal - lasts about three years before the first drip
2-Piece BOP seal - about 8 years and counting with no leaks
1-Piece BOP seal - about 4 years and counting with no leaks

* Proves that a shop can purchase the newest and latest equipment and still screw things up royally. Our local shops only do line hones so we drove 100 miles to a recommended shop to have them muff up the line bore).

We were out of two-piece RMS01 Viton® Rear Main Seals for a bit but now have them back in stock. Serrations can be an issue if they are aggressive or deep. Otherwise not a problen with either the two-piece or one piece rear main. The key to installing these seal is to fit them to the block. That means taking material from the OD rather than the ends (two-piece). That means taking material from the OD rather than making multiple cuts (one-piece) The crank needs to be out to install the one piece for the specific reason of fitting the seal to the block. You put the seal in the block and cap and look at the cut. If there is distortion you sand the OD until it is minimized or gone. When installed this way there is no better seal on the market. Call anytime with questions! We take calls evenings and weekends as well.

Thanks for taking the time to respond here Wade, very much appreciated. We've used both your 2-piece, as well as your 1-piece, and have had excellent results with both. We always make sure the serrations are not too aggressive before installation, and have never had a problem. Thanks for the great product....