coldfire7

Hi,

I was just wondering what companies sell ceramic apex seals for the renesis rotors, and for what type of price ranges?
also, do using ceramic apex seals require any modifications to the rotor itself or the other rotor seals, and does the rotating assembly need to be balanced differently?

thanks
- Aaron

rotarygod

There are currently no ceramics available for the Renesis. Ianetti is working on them. In order to use the current ceramics you would have to machine the rotors so that the apex seal grooves are deeper to accomodate the 13B seals. Unless you are building a new high output forced inducted engine, there is no point to using ceramics. Ianetti seals run around $1600 for a set. JHB also makes ceramic seals for about half that price but Mazda Japan has tested them and found them to be brittle and inferior to the Ianetti.

PUR NRG

Mazda Motorsports has been offering Ianetti 2mm 1-piece and 2-piece ceramic apex seal sets since August of '03 specifically for the RX-8. No idea if machining is required.
________
Pain management advice

Red Devil

The stock seals in the 13B-REW were good for upwards of 500hp, as I recall. If so and the Renesis seals are rumored to be much stronger you'd have to have a very ambitious project to want to go to ceramic.

Rasputin

Considering the amount of work (and engine failures) that went since 1961 into finding the right match between apex seal material and working surface coating, I hope Ianetti knows what they are doing.

Fabrice

rotarygod

Francesco Ianetti makes the best apex seals on the planet. For the price they'd better be good. These are the seals that were used in all of the Mazda race engines and in Abel's engines. He does not currently have a Renesis seal but is working on them.

sburkett

So who has been making the ceramic seals that the Pro Formula Mazda and Grand Am cup guys have been running all year? I thought Ianetti was making them?

New "taller" ceramic seals that are supposed to be more durable than those mentioned above already exist, they are being tested by Mazda. Should be available "any day now".

Steven

p.s. just checked inventory at mazda motorsports, not available yet...

coldfire7

well, i am just trying to get pricing of various options for an engine build.
i was considering using the renesis rotors in a conventional 13b build up. however, the engine would be a bridgeport of some kind, or possibly a PP. i do not trust using the stock renesis steel seals in that application from what i have heard and researched.

i had heard of a few people using ceramic seals instead of machining for the old style 2 or 3 mm seals. i had assumed i guess that this meant ceramic seals for the renesis rotor specifically...

so considering the cost of ceramic seals ON TOP of machining, stock 2mm Mazda seals from the FD probably seem like the best way to go...
actually considering it all, the renesis rotors i'm kind of getting turned off at this point.

thanks
- Aaron

Rasputin

That's what I call good references!!

Thx,

F

Aseras

don't forget that the renesis rotors are higher compression, you'd have to dish them to lower it or really tune the heck out of the car if you are talking serious FI power..

rotarygod

There is really no reason to go to ceramic seals unless you are going for insanely high horsepower numbers and have money to burn. There are no ceramic seals available for the Renesis at this time. Any info that says otherwise is wrong. Using Renesis rotors in a 13B has also not proven to be a benefit up to this point. Mazdatrix has actually gotten less power out of the Renesis rotors than they have the 89-91 nonturbo RX-7 rotors which were 9.7:1 compression. The seal clearances on the Renesis rotors is too great and there is more leakage than in the RX-7 rotors. The RX-8 rotors are cheaper but if money is really an option ceramic seals wouldn't be condsidered. The best rotors to use for a 13B build would be the super lightweight assembly from Racing Beat. These are $1200 but are lighter than the Renesis rotors and would have less seal clearance issues. To date these are still the most powerful n/a 13B rotors you can get. Just use stock Mazda 2mm seals. You'll be fine. They are far better than many think and are definitely better than any aftermarket set except the Ianetti. At $1600 a set for tehe Ianetti vs $400 a set for the stock, the Ianetti had better be good. You do understand that you will have to have a bridge or peripheral port engine to even get the power of a stock Renesis don't you? And this will be sacrificing so many other things. Race use due to class rules is one thing but if there is any street use at all, lose the idea of a bridge or peripheral port.

coldfire7

yes, i was underestimating the cost of the ceramic seals, and i was under the assumption that they were being manufactured for the renesis.
i will be using a lot of renesis internals, but looks like the rotors are not going to be part of that.
it's not that i don't think there are gains to be had...some people have had success with them. i partially also wanted to try them out to see how the engine would turn out.

but looks like S5 NA rotors seem the way to go...

anyways, my car will see track time, but it is primarily a street car (daily driven).
i don't see bridgeporting a big deal...i am willing to sacrifice a bit of driveability, fuel efficiency, etc.
i want to use good internals so i can have a fully reliable engine that can see track abuse AND take me to work.

i am not considering a full bridge. right now a bridge on the aux and secondaries (that don't cut into the rotor housing) is what i am thinking...

i know what EMS i am going with, and i will be building that shortly (take a guess as to what it is, heh).

only area that is still fuzzy for me is intake manifold...stock one won't give me the full gains of the BP, but a custom or IDA might be $$$ and sacrifice even more driveability...

Blake

That's news to me. We built a ported, ceramic seal RENESIS today. They were NRS Ceramic seals.



--
Blake Qualley
Pineapple Racing

rotarygod

I was referring to Ianetti. NRS aren't those brittle Canadian units are they?

Blake

If you say so.

Canadian, yes. Brittle, not that I am aware of. I noticed you said something to that effect before...something about Mazda Japan tesing them (JHB does not make ceramic seals so I presume you meant NRS)? If you could give me a name, I will call them directly and confirm your story. We've had great luck with them and so have many other notable engine builders. Rohan at GURU Motorsports tested them back-to-back with the Ianettis in the same engine and was very pleased. Perhaps that is because the material used, as I was told, is the exact same stuff that Ianetti is using. The only differences would be the machining.

That said, you are probably going to see more inexpensive seals broken than expensive ones...people who are on a budget more often cut corners than those with unlimited funds.

The other comments you made about ceramic seals, I also do not necessarily agree with. Ceramics are EXCELLENT for non-turbo engines, primarily because you can run stronger springs and, thus, improve sealing on the major axis, increasing torque across the powerband.

[EDIT] BTW, I'm not trying to be argumentative; just sharing our experience. Perhaps you have personal experience to the contrary?[/EDIT]

--
Blake Qualley
Pineapple Racing

zoom44

Blake,

Hi didnt get a chance to say hello at 7stock but i pointed you out to a few people and told them about your work on rotaryillustrated.com. for the folks here that dont know Blake is the man behind that website.

What kind of porting did you guys do and do you have any pics? What is the engine going into- back in an 8 or some different ap? What did you do with the exhaust?

-Charlie Dulin

edit- btw i won a set of corksport rx-7 braded oil cooler lines at the 7stock raffle- you guys want them?

Blake

Thanks. I sold Rotary Engine Illustrated to someone with more enthusiasm to finish it, but still help out on their new technical forum and will be writing some technical material as needed.

I'm not at liberty to say what was done or to show pictures or the ports. Unlike the RX-7 stuff, this is all new territory and those who innovate have to protect their work to have any sort of advantage going forward.

Thanks, but no. We make our own. Maybe Corksport will buy them back from you?

ddub

Go onto rx7club and sell them, they'll sell. I love my corksport SS oil cooler lines on my 2nd gen, great quality and price.

ddub

You guys port the Renesis now too? Any insight to what type of design you did, especially the exhaust port? So far it seems like theres not a whole lot to be had on the Renesis, especially the exhaust ports.

Blake

Can't get too into it, as I said in the other post, but this was a turbo engine and it required different port timing. I agree, the RX-8 is a tough nut to crack. Mazda did a great job getting the most out of it, so we are just fishing for scraps. Our biggest concern with the engine are the apex seals, right now. The engine we just built was a 20K seal failure and the side ports and chamfered rotors make it a meatgrinder...the seal pieces can't escape out the exhaust and they get dragged between the rotors and housings. All we could save were one side housing, a rotor, and the eccentric shaft (one rotor housing was okay, but we don't re-use those anyway). Ouch! Everyone seems to be designing a taller apex seal but the problem there is exposing the ends to the exhaust port (heat and carbon buildup). We have some ideas and will be trying them out on our R&D engine, but these things will take time to sort out with any confidence of durability.

--
Blake Qualley
Pinapple Racing

zoom44

think Rob would answer for an article in rxtuner? ive been meaning to get in touch with him about one anyway. "10 questions with Pineapple Racing" shoot me a PM

Bonchichio

I was just curious, Blake, if you could please disclose the cause of that turbo'd renesis' apex seal failure. Was it related to boost or detonation or something else?

Blake

Sure. Email the questions to me at blake@pineappleracing.com.

Blake

It was just a stock engine in a basically stock RX-8. Because of the aftermarket air filter and cat-back, Mazda refused the warrantee. The driver was young and drove it enthusiastically, but his parents drove it the last 500 miles. This is the story I was told. I think the owner could have fought the decision but they have the resources to do something else...so, turbo RX-8 it is.

glassman

Yes I too would like to know your source. I am not aware of any testing of my products in Japan let alone testing done by Mazda Japan.

If you will be kind enough to give me the source I will happily arrange for Mazda Japan to get a set of NRS "Grey" seals for testing not the more affordable "Black" seals.

I will pit my "Grey" product against any apex seal, any where, any time.

As far as Ianetti having the best seals, that is highly debateable as others say the same about NRS Ceramic Power Seals.

To be completely honest, I don't know if the material Ianetti is using is the same and I don't care. My material was chosen because it was simply the toughest available and best suited to our applications.

Regardless, testing will begin soon on NRS' new material that is the toughest ceramic of it's type in the world......PERIOD. Initailly they will be tested in 3mm 1 pc trim (drag car in PR) as well in some engines in the form of a Rotary FIRST...NRS Ceramic Corner Seals.

That's right NRS Ceramic Corner Seals will go into production within a few weeks time. Testing will begin immediately upon completion.

Regards