Has anyone installed the Superformance rear main seal SFP9340 from Mancini? Unlike the FelPro, the "ears" appear to be detached. I was wondering how these installed properly? Do they just butt up to the outside of the seal or do you install them in between the ends of the seal? Are they better or worse than the FelPro? This is the 3rd time the rear main has been done and the last 2 times the FelPro was used.
340 Rear Main Seal Install with Superformance Seal?
- Thread starter clinteg
- Start date
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TrailBeast
AKA Mopars4us on Youtube
Put half of it in the cap and if it doesn't go all the way flush with the surface of the cap on both sides you have your answer.
I wouldn't expect it to go between the ends of the two halves though, as that would double the amount of gaps and double the exact problem one piece seals solve.
I did a search and couldn't find installation instructions, but I did see where they have a double lip seal rather than a single.
They are apparently capable of intermittently withstanding higher temps than normal seals, but I kind of doubt our engines would ever get up to 450 degrees.
I wouldn't expect it to go between the ends of the two halves though, as that would double the amount of gaps and double the exact problem one piece seals solve.
I did a search and couldn't find installation instructions, but I did see where they have a double lip seal rather than a single.
They are apparently capable of intermittently withstanding higher temps than normal seals, but I kind of doubt our engines would ever get up to 450 degrees.
Put half of it in the cap and if it doesn't go all the way flush with the surface of the cap on both sides you have your answer.
I wouldn't expect it to go between the ends of the two halves though, as that would double the amount of gaps and double the exact problem one piece seals solve.
I did a search and couldn't find installation instructions, but I did see where they have a double lip seal rather than a single.
They are apparently capable of intermittently withstanding higher temps than normal seals, but I kind of doubt our engines would ever get up to 450 degrees.
I wouldn't expect it to go in between either. But if they just butt up to the outsides of the seal, what purpose does that serve and does that not make another point to leak from? I don't think I'm looking at it right but I'm trying to grasp it all. I couldn't find instructions anywhere either and the guy at Mancini didn't act like he knew exactly how they go in correctly. I called Dvorak and apparently the seals he used to get are no longer produced and they wouldn't even sell him the dies. But he very profoundly noted to make sure there was ZERO sealer or anything on the ends of the seals and to make sure to not put ANY sealer between the cap and the block. He said that the cap needs to be fully clamped down to provide the correct seal and adding any sealer prevents this. He also said do not clock the seals like some people do. His claim was that this will prevent the seal from keeping perfectly round when the cap is torqued, but I don't know much about that. So far, that's all I have to go off of.
TrailBeast
AKA Mopars4us on Youtube
Sounds like crap to me, as there isn't a chance in hell I wouldn't use a thin film of RTV from the seal edge to the outside of the cap.
That "won't be round" thing sounds like BS also, because that's what the groove in the block and cap are for as well as determining clamping force around the entire seal.
I probably would be ok with those little ends as all they have to do is block that channel in the block.
I gotta tall ya, I would also clock the seal and a tiny little dap of red RTV on the ends where the seal halves come together.
Now I see why you decided to ask.
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Now I see why you decided to ask.
I know right!? I've read all these different ways to get these sealed and every guy swears by his way and they're all different in which way they installed the seals.
TrailBeast
AKA Mopars4us on Youtube
Well I know how that is, but if it makes you feel any better every single one I have ever done (probably 25?) was done once and never leaked again.
But I'll spare you another opinion.
I read when I looked them up where they came with installation instructions, but not yours huh?
Well I know how that is, but if it makes you feel any better every single one I have ever done (probably 25?) was done once and never leaked again.
But I'll spare you another opinion.
I read when I looked them up where they came with installation instructions, but not yours huh?
It hasn't showed up yet so hopefully there will be some instructions. I bought some Right Stuff. I could use that on the ends of the seal instead of the red RTV right?
TrailBeast
AKA Mopars4us on Youtube
So when I called Mancini the first time, they ordered and sent a 9440 B/RB seal. So I ordered online this time and made sure I had the correct part. The order on the invoice is correct as a 9340 but guess what? They sent me ANOTHER 9440 B/RB seal. WTF Mancini!?? So I called and finally received the right seal the third time. Note the differences in the seals. The Superformance seal appears to have a better design than the Fel-Pro to me. You be the judge.
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6pkScamp
Well-Known Member
Don't use silicon. The end of the seal sticking out past the surface is what gives you your seal. The crush of the two ends meeting is all you need. Any silicon on the mating surface of the cap could change your bearing clearance.
For what it's worth, this info is from my engine builder.
For what it's worth, this info is from my engine builder.
Marcohotrod
Well-Known Member
I use a little silicone , and tighten the cap while the silicone is fresh, any excess squishes out, not affecting clearance. and this is not just theory, I have measured bearing clearance before and after a small amount of silicone. no leaks with fel pro
Here's my report back on how I installed the seal and results. Using information here and just looking at how the seal functions, I made a decision on what to do. On the cap, I used Right Stuff in the corners where the ears meet the seal (on the vertical and horizontal seal surfaces on the back side). I put a little bit under the ears as well. On the block, I spread right stuff over the entire cap mating surface. I wiped it so that it was a very very thin layer. I then applied a very very thin layer of right stuff on the ends of the seals. I DID NOT clock the seals at all. I made sure they were square to the engine because I really just didn't like the idea of the clocked seals so I didn't do it. I felt that the design of the seal plus the sealant would be sufficient. I then put the cap on and torqued it down. Waited about 30 seconds and gave it a retorque. A bit later I applied a second retorque and that was it. Sealed up the pan with right stuff and threw it on an engine stand. So far, ZERO LEAKS (except for a bad weld in the pan)! I'm going to wait and put it through a few heat cycles before I say it absolutely worked. Here she is on the engine stand. I'm really hoping this fix did the trick.
dibbons
Well-Known Member
I would like to follow up with clinteg on how his rear main seal is holding up but his mail box is full.
Sorry about that. Rear main is still holding up. Been to the track a couple times since. Only leak I had later was around a loose pan bolt.
Blind Squirrel
Well-Known Member
You spread a thin layer of sealant on the mating surfaces of the main cap? Definitely not a professional building practice. They are machined mating surfaces for a purpose. Ever hear of cap fretting?
Anyone building a motor at home please do your research and follow sound building information and practices, not keyboard samurai warrior's using youtube video's and harbor freight weapons of mass destruction. Do it right or do it twice.
Anyone building a motor at home please do your research and follow sound building information and practices, not keyboard samurai warrior's using youtube video's and harbor freight weapons of mass destruction. Do it right or do it twice.
Oh please old wise one. Tell us more since you obviously think you are the master engine builder! Tell us how awesome you are! Go on!
And by the way, I took that advice from a builder who was the national record holder for several years in stock eliminator class. He built his own engines and countless for others. If you know **** about stock eliminator, you'll know how brutally tough that class is and what it takes to be at the top. Tell us, what national record have you held with engine building!?
I always use a small dab of silicone on the seal ends and a little on the block where the cap meets and I don't give a royal damn what anybody else thinks about it.
Blind Squirrel
Well-Known Member
I do also. But what I don't do is spread "Right Stuff" across any machine surface designed to mate to another machine surface with the clamping force designed to hold the reciprocating pieces of an engine together. (again, research fretting)
I will also state clearly for the record. I am not a certified expert nor do I hold any national records for engine building. I have plenty of things that I could toot my own bugle to but I'm not here to try an impress anyone. I try not to hurt, only help. (I can see where my statement above was a bit bite'ish, sorry). If you really need my bona fides I'm sure I can come up with a long string of facts.
You can find experts on either side of a fence on almost any subject. I forget, are eggs ok to eat again this year? My point is, "Best" practice is NOT to spread sealant between two machine surfaces designed in the clamping force of holding the crankshaft in place. I will back this up with; Not one engine manufacturing company uses any sealant in the design or assembly of the main caps of their engines. There is not one manual written for the automotive industry that advocates what you suggest. Finally, there is not one note in any of the aftermarket publications that discuss the building or rebuilding of engine that recommend what you suggest. (Every hear of Smokey Yunick?)
Again, I am sorry if I offended your sensibilities. I didn't mean to. But people read and learn from what is posted here and elsewhere on the net. It somehow becomes gospel if not challenged. I choose to challenge and inform. But I am not above learning. Thank you.
Also, research Astroturfing Youngster.
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You didn't offend me blind one. I was just adding to the conversation.
Ironmike
Well-Known Member
Hey man. Glad it ain't leaking. I'm on my 4th one (4 engines). They are bombproof.
I had to call him just today because I ALWAYS forget which way they go.
Greg, the owner of Superformance told me they won't be making them any longer. I believe he said they lost the material supplier. I'm going to buy 2 or 3 more for future stuff, while he still has some.
I had to call him just today because I ALWAYS forget which way they go.
Greg, the owner of Superformance told me they won't be making them any longer. I believe he said they lost the material supplier. I'm going to buy 2 or 3 more for future stuff, while he still has some.
Marcohotrod
Well-Known Member
a small amount of sealant can help, any excess will squeeze out when the cap is torqued before the stuff hardens. I have used a special sealant made by loctite? for sealing 2 machined surfaces that do not use a gasket. look at a machined surface like a main cap under a microscope
Blind Squirrel
Well-Known Member
At the risk of sounding like a broken record. Please research what I have previously spoken of. Fretting. Also research "Ted Talks Astroturfing".
Now, on to my reply. I researched the official site for loctite and could find no reference to any type of product that they recommend using on the machine surfaces of engine caps before assembly. Do they have bearing retaining loctite? Yes, used for a totally different purpose. There is not one reference in any official publication on the use of any substance between the machined mating surfaces of engine main caps. Is there reference to coatings on bolt threads and different torque values for dry or coated bolts? Yes.
Anything that can allow a main cap to creep is a very bad thing. Silicone between the mating surfaces is a bad thing. If you look at the pictures he posted of his main cap mating surfaces, I'd want to know what the imperfection is to the far right of the picture. I'd be very worried that the surfaces aren't true, thus allowing all kinds of issues. Maybe the kind of issue he was experiencing. What about the uneven wear pattern in just the one main cap bearing. And have I looked at the machine surfaces under a microscope? Not sure were we are headed with that one. But I'll say NO just for factual reference. I'll also say that some machine surfaces have specified surface finishes. Think head gaskets, but that's another story.
Let me see if I can explain this a little easier. When your building an engine or anything for that matter. It's like traveling down the highway with guard rails on both sides. If there is a lot of tolerance in what your building, the guard rails are very far apart and your chance of crashing into them is very unlikely. No mater what kind of mess you make of things. Think farm equipment, mostly operated at low rpm, minimal wear, minimal heat. So you can have a lot of variances all over the road map and the thing will work all day long. Hell, olde Jon boy down olde creek road can fix that for you. I hear he has an awesome set of tools.
Now lets step up a bit. Your daily driver or in your case the street/track car. The guard rails are a bit closer together, and even closer when you run at the track at even higher rpms. Your tolerance must be held to a bit higher standard. Will snake oil tricks still work? You bet. But your chance for failure increases. Let me ask. When building a motor and doing your final plateau honing of the cylinders. Should you wipe them down clean with a paper towel soaked in a 50/50 mix of WD-40 and AFT fluid? Some say yes, some say no, some use a different magical blend. Is it wrong? Not if fits between the guard rails. Is it best practice? I don't know, how many box cars of paper towels did the big three order last year for there engine build shop.
I could carry this farther. Let take for example the space shuttle. Even with the best practices and hundreds of certifications and inspections. Things can fail. Why? Because the damn guard rails are so frecken close together, there is no room for "I read it on the internet, it must be true, it worked for me.
In closing. I will say. It is not the best practice to apply any coating between the machine mating surfaces of the main caps before assembly and final torque. They should be clean and true. Apply a touch to the seal ends, clock the seal ends? Sure if you want. Put some in the corner of the main cap after assembly? Sure why not. But assemble a motor with coatings where coatings don't belong. LOOK OUT FOR THE GUARD RAILS!!!
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Not a machinist by any means, but for those wondering about putting sealer on a machined surface, I can tell you that from my shipbuilding career, I know that Naval steam turbines are metal to metal surfaces on the casings. There is no sealant used. "Scrapers" (a dying art) spend many hours mating the casing surfaces on board the ship, but no sealants are used. Just my 2 cents.
I understand that completely. We should never take everything we read here on these forums as gospel . We post up suggestions, experiences, etc and people can read and take from it what they want. You can throw in your input all day long and I think it's great to have the information out there. I can appreciate your efforts in trying to bring the fretting issue to light. But sitting there calling me out as a "keyboard warrior" won't fly. I don't put up with that bullshit. Speak your opinions, facts, research papers, whatever you want to post about how to properly assemble an engine. But leave it at that. Personal jabs are unnecessary.
Hmmm...I'd hate to see them stop making these seals. I really like the design of them. Maybe I ought to pick one or two up myself just in case!
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