Hi guys,

This is my first semi p port build and just wnt ask if im heading to the right direction. I already have 10.0.1 rotors, e shaft and gears from a renesis motor and thinking of putting it in a semi p port Rew block. Thinking of using Jays intake with for barrel carb setup just to cut some of the cost versus injected. instead of spending money on electronics I'd rather spend it on the motor. Like get the rotors cut to 3mm and maybe get it balanced to 12k. like I said this is my first semi p build so I need some guidance from experts like you guys to lead me to the right path... Thanks....
Once I get started on the build I will post pics of what I've done. Thanks again....

 

You're obviously misinformed. 3mm and high RPM don't mix.

 

What I heard its better n it won't be sticking... So should I still cut it to 13b seal or stay renesis seal?

 

i suppose you could try the 10:1 rotors but most others haven't had great success with higher compression making more power, maybe a slightly more flat torque curve.

mill the 2mm slots deeper for early seals and ditch the stock renesis apex seals, they are too shallow for a PP motor.

3mm are not good for a high revving n/a motor like you're suggesting, unless you are using ceramics. which i still wouldn't use 3mm ceramic, stick with 2mm.

 

I gotta start lookin at junkyards for rx8s now...

 

That's good too know, thanks fr the advice... Is it ok to use carbon apex seals? I'm trying to race nasa, I just wnt a good reliable engine that will take some abuse. You guys think my setup will be good fr track use?

 

I have an entire rx8 rotating assembly for sale. Everything from eshaft,stat gears,rotors, most original seals, front stack up and rear counterweight.

 

Thanks bro but I already have a renesis motor. Maybe if I screw this one up I'll b looking you! Hehe....

 

Yes you will need to get the whole rotating assembly balanced for safety measure(rotors,eshaft,counter weight, flywheel).. Cant wait to see the finished product..

 

Do you guys know other places that does balancing besides RB? There was one in LA but they went out of business.

 

if you're going to run it over 8000 on a regular basis, carbons are a good idea. over 8k balancing is good too.

if you're only gonna go racing, you might think about skipping the side ports and just go pull PP, its simpler

 

carbon seals are fine for n/a high RPM use, they don't last nearly as long as ceramics do though.

 

true, but carbons are cheaper, so that lets you spend more on other things like rotor housings, oil seals, balancing etc etc.

 

chipsmotorsports

 

Any place located in Cali or near LA?

 

A cheap serious NA build won't happen ! Sadly but thats true I would be the first one to buy it I am not an expert at all, I am just researching this exact topic for a few years now so I can build my own high performance NA motor.

For an NA to make power you have to rev it up, for it to make more power you have to rev it up higher with all the drawbacks that comes with it ...

I don't know why you want the renesis rotors, the FC series 5 NA rotors should be plenty good with 9.7:1 compression ratio and they are lighter too then the series 4 ones. Ceramic apex seals are the seal of choice for high revving applications is what every engine builder tells. They are expensive (don't ask me how I know) but obiously the best choice. I don't regret it as far as my motor is concerned. Balancing the rotating assembly is mandatory, if you are a it you might get it lightened and clearanced.

In the end you might look at a list similar to mine, the block alone was 10k$, not counting intake, exhaust, ECU and various other stuff that has to be done in order to get it running on a standalone/haltech. I choose to get the engine build by a professional which was way cheaper and better than my intial plan to source all the parts together and send them out to various shops to get it done and build it myself. I expect to have the engine running at the 18k-20k $ mark, which is a damn good price for a serious NA rotary build. I don't want to know what I would be looking at when doing this with pistons...

13B 6-port NA (Just doing it with 6 ports because its fun)
High comp. 9,7:1 induction hardened rotors
RX8 eccentric shaft & stationary gears (modified)
Fully lightened / balanced / clearanced rotating assembly
Ianetti 2 pc 2 mm ceramic Apex-seals
Raceport (largest streetport possible) (I don't want to go bridge or pp)
Lapped 6 port NA irons
FD rotor housings (new)
FD oil pressure regulator (+- 100 PSI)
Turbo 2 high flow oil pump
Oil gallery modifications
Large thrust washer assembly

Here it is:

 

Wow, ur build is very nice... Were did you do ur balancing? Well I thought I would use renesis rotors due to higher compression and already revs higher than s5. Already got all renesis rotating assy. And gonna use Rew block for bigger Ports also goin semi p port on this setup. I want to use ceramic seals but the price is kinda crazy but I know its worth it. Thanks fr ur reply bro, can't wait for to hear ur motor running. thanks fr the tips....

 

Yes, the sound will most likely be awesome, however I first need to get the chassis in order, it has too much rust and needs serious welding. That will be done parallel while I build up the engine, so everything will go together at the end. Startup will most likely be mid 2013.

As for the renesis assembly, If you have them you might as well use em. Get in touch with an engine builder as the RX8 rotating assembly in not exactly bolt in to the RX7 engine block. I cannot tell what exactly has to be done to make it work as I never did it, and mine has been build by a shop. You might as well ask them about the apex seals. Got my engine and balancing done by Adam Heyman (rotaryengine.com) Personally after going through the build plan with Adam I would not build a high performance NA or turbo motor myself in my shop/garage as there is too much precision work involved and tools/machines required which I don't have, and prefer it to be done by a professional. (Not speaking about porting and stuff which I can't do anyway) Thats maybe the best advice I can give.

As for the peripheral port, I can't give any advise as I never considered it as an option for me and have little to no knowledge about them.

 

Is it goin in an fc? But ya I still have to cut rotors n do lots of mods still I do have a shop that will do all my machining work palmtreerotary.com they just don't do balancing. Anyway thanks again and hope ur car build will go well. Are u tracking the car? Maybe we can meet or race together one of this days. Good luck to u n thanks again...

 

Could you use RX-8 ceramic apex seals instead of machining the RX-8 rotors for taller early seals?

If you discount the cost of machining the RX-8 rotors this way ceramics start to look more affordable...

If you have complete RX-8 rotating assembly from a single factory motor wouldn't it already be balanced well enough for 9k rpm?

It seems like if we get crafty this could be the cheaper way to do high rpm motors.

-edit- you mention balance to 12k rpm! Seems like you will need 2 piece e-shaft for reliability that high. Transmissions that can shift that high are pricey too. Maybe just stick to 10k rpm goal.

 

Yes its going in an FC, check out my build log 1986 Mazda Rx7 EU-Spec GT | THRLL.com
Just street fun, the FC isn't homologated as by the FIA, so no racing for me
So I figured, why not getting creative with it and take it to SPA on a weekend, thats my goal

 

Just a thought, if you decide to go with carbons, 3nm may not be a bad idea, as they will wear more slowly than the 2mm ones. I think you have a great platform to start from, semi-pp is the way to go IMO. Just make sure you have someone that can tune your carb for you I guess, I have zero experience with carbs on rotaries.

I can't see the rx8 assembly being any worse than S5, but just don't expect any significant gains (or any at all) over standard s5 stuff. I agree that even with 10,000 rpm, the transmission will be your biggest obstacle. I would build it as you are saying, maybe even try the carbons out to see if they will work for you (soft seal kits are cheap enough if you have to swap out to ceramics later), and just take it as you go.

 

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Well I thought about goin 3mm but most of the guys are sayin 3mm is not good fr high RPMs. As far as using renesis internals I just wanted to use a 10.1 ratio instead of 9.7 I'm not expecting crazy horsepower but I should get a Nice torque band and renesis rotors already revs higher than s5. And yes semi pp is the way and I'm goin to use pro jay intake setup with stand alone, don't really want carb. here's a pic of d rotors n e-shaft, cleaned...

 

3mm carbons would be better for high rpm than 2mm steels. The reason I say 3 mm for carbon seals strictly, is that they will wear less quickly than 2mm carbons. The only reason to go with carbon seals is they are cheap, will work in N/A's, and are light enough and soft enough for high rpm use. Ceramics are better in basically every aspect though, except that if they break they wreak carnage on engines. Steel seals will be more durable than carbon,, but don't tolerate as high RPMs as the other two without causing wear on the housings. When it comes to picking seals, you can't have everything