Mr rx-7 tt

iTrader: (5)

Mazda has put how much $$$ designing and perfecting the OEM seals for how many years? I think it's going to be tough to try and build a better mouse trap. Although I wish someone would....

I did hear of a special seal made by some company in Japan a while ago. The waiting list was 3 years. They were also VERY expensive...Saw pictures etc. but who knows...probably hipe...

Scalliwag

Mazda has spent a lot of years and a LOT of money developing all aspects of the rotary. But even their own R&D team makes big improvements on their own designs, even at the mechanical level. The side exhaust ports making the motors both more powerful with less emmissions in the Renesis for example.
That is pretty good proof that a better mousetrap can be made. Some of the super alloys available today were not even a thought when Mazda's OEM seals came out.
So in many ways there is a big advantage with what is available to test with. Unfortunately we do not have their checkbook and facilities/equipment.
But determination and moderate financial resources and lots of researching and talking to people that are experts in the particular field (in this case alloys) could turn something up.

Here is a real good example of cutting edge technology that is very impressive. This would not work as an apex seal because of temp requirements but they are working on different types of characteristics so it may someday. Go here and watch the two videos http://www.liquidmetal.com/news/dsp.multimedia.asp

GtoRx7

iTrader: (5)

I've been reading all the posts, and I have had some questions answered, but I have some more. I'm building a Turbo ll motor, so far I've done this; dynamic balancing, deep groove rotor bearings,3-window 3rd gen staionary gears, 2mm soild corner seals, 3rd gen corner seal springs, 2 new rotor housings, 120 psi regulators, and street ported housings. I am going to run a max horsepower of 400, and want a redline of 8000rpms. I only want 2mm apex seals, but I'm having a hard time deciding between stock seals, 2 piece 2mm from mazda racing.com ($600) and ceramic. Has anyone heard anything about the mazdaracing seals? Also why is it everyone says 3mm redline lower (7000) ? Before the 2mm came out, the 3mm in the GSL-SE motor according to racing beat can take up to 8500 rpm, which seems to be the "wall" that any mostly stock internal rotary of various years can take. thanks for any reply

Node

iTrader: (1)

You overbuilt your engine ridicuously.
About all you needed to have done is port it and dowelpinn the engine. But the other stuff is nice, but not truely needed for your goals.
Go for stock 3 piece 2mm seals, theyre great, and if you ever detonate with ceramics say goodbye to your engine. Ceramics will withstand more detonation than normal seals, but THEY WILL break just like normal seals, and being ceramic will rip apart your housings, rotors, and turbo.
Are the mazdaracing ones the carbon aluminums? If so those are only for N/A applications.
And if by 120psi regulator you mean oil pressure regulator, that is too high and you should change it.
Sounds like your engine is built for high RPMs, maybe you could change your goals since you've already built it so nicely.
Have the rotors clearanced, and make sure that the ports and turbo can flow for higher RPMs.

vosko

iTrader: (4)

120 psi oil pressure regulator is fine just go with stock mazda seals and buy a wideband O2 sensor for your car and you shouldn't have any engine problems

CrackHeadMel

iTrader: (2)

i read somewhere at mazdamotorsports (cant find it now though) that running anything over 100psi on our motors runs excessive oil blowby

680RWHP12A

the seals i sell now are made of a high carbon steel, they work great....the only problem i have had is on my bridgeport the housings get scratched after about 60 runs but that is not the case with the 2 mm seals, proabably because of less surface contact with the 2mm. but we are all looking for something better!

here is my seals for reference....


http://www.rotaryshack.com/pages/raceseals.html.

BLUE TII

iTrader: (9)

GtoRX-7, don't listen to Node. I am hoping for 300RWHP and had Rob Golden (Pineaple Racing) do that stuff and more.

He is known for his oiling system knowledge and includes high flow pump, ported oil flow passages, high pressure regulator, oil loop line to balance pressures, relocating the outlet to oil cooler, cryo-ed/grooved/windowed bearings, 3rd gen bits, baffled pan and more to his oil mods (stages 1-4 available).

My stock guage reads 30 at idle, 60 ~2,000rpm, 110 ~3,000rpm and pegged ~4,000 and up.

I have a completely open exhaust and it does not smoke and oil consumption seems to be just on the higher side of normal (~1 quart/3,000 miles) simply because the oil injectors are getting more pressure. But I have my mechanical OMP set-up to be adjustable and went w/ more than stock arm movement anyways.

Maybe he can help you out- he is a great guy. I would understand if he has to keep that info between paying customers and himself though- but, worth a shot!

Ah, this is about apex seals though. Uh, well- Rob recommended 3mm seals for me He believes they are more robust.

Now, Mazda is going to use 1.5mm seals in the Renisis, right. So, I would say Mazda's newest advancements are NOT always the best for all performance applications even w/ all their R&D. They simply have other concessions to make. 100,000 mile + life expectancy, emmisions, cost and then LAST of all performance related criteria.

I'm guessing the 1.5mm are lighter and have less friction- so they seal better for less emmisions/ more hp, require less oil lubrication for emmisions and can do higher rpm for hp. Hmm, everything they said about 2mm seals.

Not having a periperal exhaust port to span probably has a lot to do w/ it as well- I can't discount that.

Are we going to retro turbo p-port exh. engines to run these 1.5mm seals just because they are Mazda's newest development and they must know best- I doubt it.

I think we w/ high horsepower turbo engines can throw out many of Mazda's most important design cirteria.

100,000 miles + life expectancy- Ha!

Emmissions- Ha ha!

Cost- Ha ha ha!

Now, why the hell should we assume Mazda has designed the best seal for our application?

GtoRx7

iTrader: (5)

The Renesis is running 1.5mm? Whoa thats cool, I was wondering how they were getting 9k reliable ( and most likely 10k pushing it since almost all motors have to take 1000 more rpms than what the tach says for breif moments of time, simply for the safety reason) That really sucks like you said for the turbo guys, as of course its a fully built N/A motor, and unless we are real lucky, it wont withstand boost long. Oh well. And yes I did over build my motor for more than I'm expecting, I wanna have some elbow room for future upgrading and also its the one time I get to build up the motor, so its getting the works. I know its controversal, but in a way I'm trying to build a rotary that has good turbo power with wide powerband, with the rev potential and throttle response of a mild N/A motor. Hence being built to take high rpm, and not using the heavier seals. Also the oil pressure, they were recommended to me by the racing beat tech, and my dad who has built quite a few racing motors (older bridge ports back in the day) has ran that high of oil pressure. I just want to be safe at the higher strain of high rpm and high power. I hope it works out, this summer I will not see the potential of the motor, as I can only afford the stock turbo with exhaust and front mount, with runs out of air around 6000rpm (so I heard). But soon a TO4 will find a happy home in there and up the tach will go to 8000 with the smooooothness only found in a balanced rotary! oh yeah.

BLUE TII

iTrader: (9)

NO, NO, NO, NO!

You cannot run a decently flowing streetport engine off the stock turbo- it will boost creep insanely!

On my streetport build up I tried a stock hybrid-
89+ turbo + manifold
ported WGs
bored exhaust scroll and exit for larger wheel
"O" trim wheel clipped 15 degrees
60-1 Hi Fi compressor

It boost crept to 20 psi (WG set to 6.5 psi) by only 4,000rpm w/ richer than 8:1 AF killing boost and greddy relief valve open since 15 psi.

Be careful- very careful. Luckily, my engine and fuel system were built for 20 psi boost no problem.

Sorry to stray off topic again- just don't want Gtorx7 blowing up his engine.

GtoRx7

iTrader: (5)

Thanks!!! I've had a hard time find info on this , wish I read your post before asking more questions. Oh well, guess I gotta get a To4!

Chronos

Resource, you have to assume that Mazda has thought of pretty much everything allready, so you're not going to be able to get better seals than OEM...unless you go with the more expensive (though well worth it) Ianetti ceramics which my engine will have shortly.

With your power goals and proneness to blown motors (no offence ) I'd say go with the 1 peice 3mm units, they're the strongest seal you can get capable of withstanding multiple detonations before going. Aside from being much stronger they also have many other attributes. 1) They're lightweight so the rotor will have less rotational mass enabling you to run higher rpms easier. 2) Their lightweight allows you to use harder spring pressure creating a better seal. 3) The ceramic material has a much higher floating point than the metal units...this means that they will not push away from the housings when large amounts of heat are generated with the friction of running at high rpms. 4) The ceramics have self lubricating properties which will create less heat from friction and extend the life of your housings. 5) THEY'RE SO STRONG THEY'RE REUSABLE! As long as you don't break them with tuning detonations, you can actually reuse them on the next rebuild!

Now, in regards to using the 3mm units (%150 stronger than the 2mm), you will experience a problem with the seals sticking if you don't machine out your rotors PERFECTLY, this is caused because the ceramics are much stronger and they won't ware away to fit the seal if they're not perfectly fit, this will result in continuous sraping or "sticking". I say it's definately worth it to use the 3mm, JUST MAKE SURE YOUR ROTORS ARE MILLED PROPERLY! The 2mm doesn't require rotor milling so they ofcourse won't have the possibility of this problem. Also...although the 3mm is %150 stronger, it's also %150 heavier than the 2mm units. So that means they'll have more friction against the housings resulting in a lower float point. However, I don't think it will really matter for you...you're not planning on running over 10,000rpm are you???

Regarding the 2 peice option...the 2 peice seals will supposedly seal better at low RPM's (4000rpm) resulting in greater streetability. It seems to me, however, that you're concerned with just all out power so I'd stick with the 1 peice. At higher RPM's the 1 piece will seal just as well as the 2 piece. As for me, I'll be using them because I only plan on reaching 500rwhp at the VERY most and the 2peice are capable of running 600rwhp all day at 24psi.

Lastly, since you probably plan on running 600+rwhp you should probably get some dowel pins to hold everything together...never hurts to be safe! I don't think I have to mention fuel delivery do I??? If you haven't figured out that that is the most crucial key in tuning, then you don't have any business at 600rwhp Also, make sure to compensate for all that power with stronger driveline components and rubber to actually put it to the ground. You might also consider using some nitrous to spool up your turbo if you're concerned with turbo lag.

Good luck with your projects!

Chronos

Hey, I hope you see this Resource...I spent a long time on that post

tmiked

Don't forget, when Mazda develops apex seals, cost is one of the main considerations.

Titanium is gall city and would not be a good choice.
The suggestion of beryllium probably was thinking of beryllium-copper (BeCu) this is a high strength beryllium alloy that is very gall resistant. I am not sure if the coefficient of thermal expansion of Be-Cu is compatable with rotor/housing materials.
I think for street engines, builders usually want the seals softer than the housing. That way the (cheaper) seals wear out before the housings.
For racing, you gotta use the best available, hence ceramic. Besides ceramic, carbon-carbon is another possibility. It is brittle like ceramic but has a lower coefficient of friction and absolutely NO galling problem.

Interesting, probably the two best high-tech choices for apex seals are both currently being used for brake discs

We just need a few extra engines and a few hundred hours of dyno time and we could solve the problem.


Marcus !! ¿ Que Pasa ? I finally got my car running again

Mike

Chronos

Indeed cost is the reason that Mazda didn't use carbon-carbon and caramics for their seals. Carbon-carbon may have a lower coefficient of friction but it's a lot softer in comparison to ceramics and won't hold up as long or resist detonation as well. I beleive ceramic is the best combination of strength and friction. It seemed to me that Resource was building his motor for all out power...maybe a new set of housings every 15k or so miles is the price you pay for that

Brentis

good thread - worthy of a bump

GoodfellaFD3S

iTrader: (213)

Yeah, I agree. Very good stuff

karism

If anyone is wondering i did a follow up post on this Titanium Apex seals thread.

It didnt work at all,the engine ran for about 15min,and then the rotorhousings,and rotors were toast.

The titanium wore away the chrome plating on the rotorhousings.

Karis

ZoomZoom

iTrader: (2)

I just aquired some of the Renesis 2mm 2 piece dual spring Apex seals for my Ported motor being built right now by ITO at JR's Rotary. They have a special thermo coating and are supposed to make better compression that the stock 3 piece 2mm seals in the FD. There has been some real good results at the track with a 700HP Rotary according to ITO. The seals made more power/faster times at the exact same boost on the same car without any other changes. I will have the car back together in a few weeks and will post some of my own results. I also have a stock number for these seals if anyone is interested.

Chronos

I wonder if the coating can be applied to a ceramic application...

GoodfellaFD3S

iTrader: (213)

I'm very interested. How much are they? Any drawbacks to using them? Any other relevant info would be great

Rich

tmiked

ZoomZoom please update us when you have some info.......