New ONE PIECE Rear Main Seals

funny, you still have to cut them up to get them in...so now you have a 2 piece seal...which is what you can buy anywhere for way less money....I guess I don't see the justification on this item....sounds like a scam to me

fastfishauto said:

A lot of effort, time, and money went into the design, tooling, and production of these one piece seals. Many have been sold, and used especially in drag race engines. They are not snake oil, out of a Cummings, and they do not have metal in them. From a materials, dimensions, and sealing ability, it is a better choice than the two piece. If you have questions please ask the people who designed it.

Thanks Jeff www.fastfishautoparts.com

Click to expand...

I'm sorry, but ALL rear main seals, excluding rope seals, have metal in them. If there was no metal, they would not be rigid enough to stay in place, maintain their shape, and maintain pressure on both the crankshaft and the housing that retains it. As far as the "out of a Cummings" goes, they use a seal retainer that you have to PRESS the seal into. Cummings Inc., Fel-Pro, etc.. have designed the seal, and it is designed to be used in a "one piece seal" application, not two. If you cut the seal, the cut removes material. Thus, when you make the two ends are made to touch, it will NO LONGER be a circle.

I'll bet the OP is happy about this.

69Bee said:

No disrespect Snakeoil, but I think this seal solution is snakeoil. They want you to simply "cut" the seal so you can put it over the crank. You can't slice a seal with metal inside for rigidity without making the diameter smaller. I do not see this working out too well, and it is the latest and greatest solution with no longevity and reliability testing. I have been building motors for a long time, and I can not remember when I had a rear main seal leak on me. If you install the seal properly, and are careful, you won't have a leak. I don't feel it will work well.

Click to expand...

69Bee I would like to try it. I had a few issues here and their but a new seal design isn't coming our way. I am thinking this is a diesel crank turbo seal. The say doulbe wiper. O well i i was thinking some thing new might be coming but i guess your right. If they cut it and its over sized without a steel spring inside what else would it use?

They used one on the slant six build on Engine Power or whatever they call themselves these days. I haven't tried them. Most of the engines I build I use rope seal in. If it's a race engine (or max output) I use the lip seal. In both cases I don't use the side seals - just RTV. I don't have leaks, even with the lip style. I am very careful about cleanliness as most leaks when using RTV come from oil being present on one or both of the mating surfaces. Even oil from your fingers can cause problems.
I could see this seal working and not faulting the engineering. I just don't have a problem it needs to solve for me.

While building a 383, I followed the instructions on the fel pro seal, and it said to soak the side strips in mineral spirits for 15 minutes then install them. I did that and they had swelled so big that they wouldn't fit in! So got another new one (free replacement) then put mineral spirits on them after installing them. That sorta worked. But that 383 still leaks a little back there. That was before I started using oil resistant RTV on them.

I have an engine going together right now that will be on the dyno shortly. If FastFish wants to send me one, I'll do a write up thread and dyno test on it.

Skip to 8:41 to see the seal installed.

http://www.powernationtv.com/episode/EP2015-02/sweet-slant-six

69Bee said:

No disrespect Snakeoil, but I think this seal solution is snakeoil. They want you to simply "cut" the seal so you can put it over the crank. You can't slice a seal with metal inside for rigidity without making the diameter smaller. I do not see this working out too well, and it is the latest and greatest solution with no longevity and reliability testing. I have been building motors for a long time, and I can not remember when I had a rear main seal leak on me. If you install the seal properly, and are careful, you won't have a leak. I don't feel it will work well.

Click to expand...

Ok your right i didnt see the cut line!

Anyone install one of these

Does the crank have to dropped or main caps loose ?

Watching that video looks like just rubber or silicone when cutting the seal , no metal

fastfishauto said:

A lot of effort, time, and money went into the design, tooling, and production of these one piece seals. Many have been sold, and used especially in drag race engines. They are not snake oil, out of a Cummings, and they do not have metal in them. From a materials, dimensions, and sealing ability, it is a better choice than the two piece. If you have questions please ask the people who designed it.

Thanks Jeff www.fastfishautoparts.com

Click to expand...

Hi

Tried it and slowed down the leak dramatically, then welded up crank as Jeff suggested to make the diameter on the higher side of original spec. Still leaked and then re-installed fastfish seal with a Brand new Mancini retainer and that finally solved it. What a battle for an oil leak. Never seen anything like it. I must say Jeff spent the time talking to us and providing solutions and is really great at customer service. Top notch. Well worth dealing with him he will really try to find a solution. On a side note: At the Mopar shop I deal with they have seen an epidemic of oil leaks and we happened to come across an old NOS seal from the 70's and compared it to a new Fel Pro seal from today's kits. Well low and behold the one from the new Felpro kit was substantially thinner. Opened up 3 different seals and the same thing. Are these new Fel Pro seals changed? Have others seen a rise in oil leaks?

Don't lose sleep over small leaks, here's what I use;

m79ded said:

Hi

Tried it and slowed down the leak dramatically, then welded up crank as Jeff suggested to make the diameter on the higher side of original spec. Still leaked and then re-installed fastfish seal with a Brand new Mancini retainer and that finally solved it. What a battle for an oil leak. Never seen anything like it. I must say Jeff spent the time talking to us and providing solutions and is really great at customer service. Top notch. Well worth dealing with him he will really try to find a solution. On a side note: At the Mopar shop I deal with they have seen an epidemic of oil leaks and we happened to come across an old NOS seal from the 70's and compared it to a new Fel Pro seal from today's kits. Well low and behold the one from the new Felpro kit was substantially thinner. Opened up 3 different seals and the same thing. Are these new Fel Pro seals changed? Have others seen a rise in oil leaks?

Click to expand...

From Superformance a few years back on Moparts

I'll tell you EXACTLY what's going on

Yes, that's the ONLY seal we offer for the B and RB engines now.

Why? Because the largest and Best 2 piece O.E.M. seal manufacturer in the World stopped manufacturing ALL of their 2 piece rear main seals. Don't matter if it was for a Chevy, Ford, Cadillac, AMC or Mopar, they dropped their WHOLE line Cold Turkey, without warning!

The orange colored Viton was not a double lip, just a single and does nothing for sealing as it's only a contaminant (dust & dirt) exclusion lip.

The black seal you have is made from a Polyacrylate rubber. This seal is made in the Exact same mold as the Viton seal and is more than adequate to seal up your motor for the amount of time it's going to be together.

Am I happy about the discontinuation of these parts? Absolutely Not! I've personally sold MILLIONS of them.

Once the black Polyacrylate seals are gone from our inventory, they are gone for good. The previous time they stopped production I bought 10's of thousands of dollars worth of product. Anything I could get my hands on..... this time, not that lucky. I only ended up with 2,000 of them for the 273-340's and could off every single one of them tomorrow if I wanted.

There have been so many changes in the automotive industry the past 10 years it's almost worthy of a stroke. Most have no idea just how deep the root is that's been pulled out

So in closing if you are not happy with the seal you have now, return it and go buy the one in the Blue package.




Got an Email back from Fastfish

Hi Scott,

It can be installed on a engine stand or in the car. I am assuming you
will be trying to install one in a car? Per your questions the only
other thing you will have to do is loosen the main caps . If you are
installing one in a car this allow the back of the crank to drop down
enough to push the seal up and around the crankshaft. The seal or joint
can go at any location. I generally put it somewhere between 4 and 8
o'clock. The seal tends to grip the block and can be hard to rotate.
You can use a pair of needle nose pliers to grap outter edge of seal to
help help push it up and around. The seal comes with detailed
instructions. I have had a good bit of customers install the seal in a
car with good results. I have seals in stock and offer free shipping.
Thanks for your interest.

Jeff www.fastfishautoparts.com

Schober Motorsports said:

Hey guys,

Just came across these on my travels... Apparently its a one piece rear main seal for big block mopars. Has anyone seen these or used them yet? Curious to see what you guys think. On a side note, from what we have on the market right now, what is the best route to go to combat the leaky rear main seal? I just fired up my engine for the first time this year and I got the constant drip coming out every 2-3 seconds. Any ideas?

Link: http://www.fastfishautoparts.com/Performance-Engine-Seals.html

Click to expand...

I'm glad to see people are designing new products for the old engines. I haven't used the Mopar one piece seal yet but I'm sure I'll start using them on my engines. One piece seals are becoming fairly common now. Roush just introduced one for the Ford FE engines and I've seen them on various BOP engines too.

I know this is an old thread but I have direct experience so here are my thoughts. First, of course you have to cut it. You'd be stupid not to know that right out of the gate. Secondly, once cut, it is NOT a two piece seal. It's still very much a one piece seal. You simply "coil it" on to install it. Very simple. I've used them on Pontiacs, Chevys and Mopars with zero leaks. They work very well. Follow the instructions and use it like it's designed and it will work very well. Ask someone who's really used them before. They are a great design and a fantastic idea for our older engines. I am getting ready to button up my long rod 225 slant six build short block and you better know that's the rear main seal I am going to use.

I had a customer get one like this (not sure it was the same company) for his Pontiac 400, and read the instructions over and over. There is a slight line to cut the seal, and the metal rib is in two pieces (upper and lower) in the rubber, and not a continuous ring. You can cut either side, but only one. They want you to install the cut in the 12 O'clock position (very difficult to install the crank/seal assy properly). I could not, for the life of me, get the damn seal to "spiral" on the crank. The rear flange and oil slinger prevented this from happening. I tried so many times, I thought I was going to screw up the seal. Finally, I had to open it up like a clam, and get it over the crank without destroying it. Cut clocking was a pain, but I finally got it together (twice). The first time went easy because Murphy was going to make sure I had to do it again, and the second time was a bitch. I finally got it, and it didn't leak, and still doesn't, because the customer hasn't complained.

I understand people developing newer and better seals, but for me, I will stick with the tried and true 2 piece seal, as it has never failed me. I want to say the the only 2 piece seal that leaked, I put the seal in the damn carrier backwards once. As far as side seals go, I wish the old style was still used. I have never heard of the 15 minute wait, I would put them in immediately, and they would swell up in place. The pipe cleaners are gone now from Fel-Pro sets thankfully, and I never used them anyway. They now use harder rubber side seals, and work well. Just to make sure all is well on a B/RB, I will fill up the outer gap between the block and retainer with RTV, and this works for me. I am sure the new seal works fine, and people will get better at installing it, but for me, I will stick to 2 piece, and when forced to (no rubber substitution), a rope seal. You want to cry about a 2 piece seal, install a rope seal...

69Bee said:

You want to cry about a 2 piece seal, install a rope seal...

Click to expand...

lol.........

RustyRatRod,

Did you end up using the fastfish seal? If so, has it performed well....no leaks?

I think I might ordered and try to install with engine in-car for my 440cu


watermelon

The engine builder I work with has been using the one piece seals in most of the engines he builds. They have been working great so far.

thanks Andyf

i have the two piece Fel Pro coming from Hughes as well as the side pieces but i might order the fastfish just for fun. either option im going to have to do the replacement with the engine in the car so i won’t have the luxury of doing any fancy measurements as outlined in the Hughes instructions



watermelon