What sort of seals are being run, company that produces them. What were your results with said seals? This goes for apex, side, corner, and springs. What were the applications for, boost, high rpm, durablity? Seems like there is a massive variety of makes and designs out there. There are to many guys out there rebuilding engines themselves and I wanted to get their opinion on whats good, before I unload 300.00 on some fancy competition apex seals.

 

what's the motor being built for? high revs, turbo, stock?

mazda seals are the jam

 

I'm heading to the world of magically boost, rev high, but not more than 8,500-9,000. I want it to brutalize other cars not itself. Kinda want the best of both worlds, durability and performance.

 

But in the end I'd like this to be for all those considering rebuilding their engines for any sort of set-up not just turbo prepped.

So mazda still makes engine internals for the 12a? How much?

 

well dont go ceramic then. yay you save money.

 

Carbon = bad for boost, good for constant high-rpm N/A

Metal = good for boost

Ceramic = Outside the realm of Jon's true knowledge

The mazda seals are good, there are also seals made by www.atkinsrotary.com and www.rotaryaviation.com which people have both good and bad opinions about.

boost to 9000rpm? I hope you know how much extra you're going to have to do to build an engine for that.... The 12a can't do that stock, let alone under boost. At the VERY LEAST

Water Pump
Oil Pump and High Pressure Bypass
Front Mount Oil Cooler (if you don't already have one)
Hardened Stationary Gears
Solid Corner Seals and 3rd Gen Corner Seal Springs
...

and the list goes on but I can't think of it all right now... there's a good thread in the archive about building a solid motor, you should probably read it.

What kind of turbo? How much HP are you lookin' to put down? You mentioned 12a, are you going draw through or blow through, or have you found an FI setup for your 12a that I just don't know about yet?

Jon

 

Its going to be a blow-through for the time being. Intercooled as well. Though I'm not trying to blow the carb apart, looking to run maybe ten pound max, but I'd like it to rev higher.

I saw these fellows http://www.mazdaracing.com/apexseals.asp
and this one has fancy corner seals. http://www.hurley-engineering.ltd.uk/tipseals.aspx
there was another one like ezzypower.com or something, it was in Aus.

I was going to get the modified RB stationary gears, and three window bearing. Even considering having them machine the rotor for better clearences. And the bulk of the mods you mentioned.

Was really curious if some of these go-fast seals were worth it. But it doesn't seem like many people have gone that route.

 

Ceramic apex seals are bad for boost? How come they were reccomended @ the SevenStock tech sessions for boost? Ceramic can take more pings is what was said.

I have ceramics in my 12a J bridge. They are made to tigher tolerances, so you can run more apex seal spring. Tighter sealing, more power than any other seal period. And light weight so they can take rpms. Other non-MAZDA apex seals was brought up, it boiled down to they're cheaper for a reason and u better hope they are made to spec every time.

 

Ceramics are the way to go but they are more expensive. And yes, they are fine for boost.

Personally I just use the standard Mazda items. They are proven to very high hp numbers. Unless you're running a lot of boost with high rpm there's no need to look elsewhere.

 

Yeah ceramics are like 1800.00 aset just for the apex seals, but they deffinitly live longer under high boost though. they also have a tendancy to wear out your rotor houseings faster also, but this a tradeoff, just like any other modification.

kenn

 

I went through the same questions when I planned my engine build.John at Mazdatrix made it very clear that stock seals (even the 2MM ones) are very stout and are capable of tremendous loads when the engine is tuned correctly.Been running 14psi into my S5 engine for years with zero issues on the stock seals.(new seals,rotors and housings)

Planning on running to the ragged edge and dont wanna risk seal failure if you ping......go 3MM.
Money no object.....go ceramic.
Plan on rebuilding often,dont want to ruin the housings,but want 9000RPM+ N/A....go carbon.
If you wanna build a moderate HP turbo engine(under 400HP) that'll hit 8500RPMS and be nice and reliable,go with stock Mazda seals,NEW housings and the lightest rotors you can get for your model engine.Save the money from the fancy seals and get some new rotor housings.

 

ceramic is by far the best seal you can use. Cost is the only real downfall to them

 

exactly... mazda seals are plain tuff

 

what.

 

I use factory in all my stock 12A builds. Apex seals are half-and-half between stock 2-piece and the carbon dealies. I've only cracked one carbon seal, and it was in the first engine I ever rebuilt, and I'm pretty sure I was running wayyyy too much timing in it. The second time I rebuilt I used carbons again, and they look good even after a hard season of racing that included a 6-hour enduro. What ended up killing it was a couple of seized bearings. Both "mains" and a rotor, actually.

 

check this out, its interesting


https://www.rx7club.com/general-rotary-tech-support-11/indestructeble-apex-seals-488606/

 

i wanna try these next.
http://www.southcoastrotary.com.au/product.htm

 

what company does cermac coatings on housing ??