Does anyone know if Racing Beat or someone else is going to make the 3rd side housing to make a 3 rotor renesis possible?

 

Nobody knows anything yet.. Racing Beat has yet to get the engine in to look it over, so who knows what's possible!

 

It would require a new eccentric shaft as well. I don't think Racing Beat has the engineering and capacity to design/build a new eccentric shaft. A 3 rotor would most likely have to start from Mazda.

 

Hevnsent, couldn't you be able to use the one mazda allready makes? or is there something you know that you haven't told us.

 

Good point, I nearly forgot about that.

Personally that's one design I wouldn't look to the aftermarket for

Mazda make some crated Renesis engines :D

 

well, amgtortiose was saying that the RENESIS e-shaft was thicker (either at the e-lobes, or down the middle, i have no idea) than a 13B one, or was at least suggesting it...??

btw, CNC machining a hunk of billet Twhatever steel into two peices to make up a 3 rotor e-shaft isn't magic... especially when you consider that RB can make side housings??? hollow-cast aluminum side housings for 13B applications?? eh??

 

The Renesis 1.3 (2 rotor) I'm not sure if it uses the 1 mm e-shaft, but that would be nice if it did... it'll make the Renesis closer to a race breed engine components. =) ... also, I wonder if this engine comes with smaller spark plugs (motorcycle size), that reduces the stress cracks in the spark rotor housing?!?

The 1992-1996 Cosmo JC3S that came with the 20B-tt 2.0 (3 rotor) engine. Could be the base to produce the Renesis 2.0. All they have to do it's use the same Renesis rotor housing, re-innovate the side plates & wallah! Renesis 3-rotor. Or, second option.....

Use a miss & match parts from the 13G, R26B, Renesis 1.3 & 20B-tt parts.... =) It's very do-able... 2 combination would be:

-20B version of the Renesis 1.3 side housing with standard 20B stationary gears.
-Renesis Rotor Housing.
-R26B Stainless rotors with standard 13B bearings.
-20B e-shaft

or

-20B version of the Renesis 1.3 side housing with 13G
stationary gears (+1mm bore).
-Renesis Rotor Housing.
-R26B Stainless rotors with 13G bearings (+1mm bore).
-13G e-shaft (+1mm bigger over 20B)...Racing e-shaft

This IMHO this would be the outstanding engine replacement for the RX-7 & will keep the public live up to it's name. Since most part will be interchangeable between both Renesis 1.3 & 2.0, like the rotors, housings, bearing, apex seals, general seals, etc. etc... & not a 10-15mm engine displacement increase which would mean re-design in fabrication & tooling.

.... and to the extra bonus 3 spark plugs per rotor housing.. I don't really know how it will perform with the side housing Renesis configuration, but in the R26B 4 rotor peripherals were gaining good torque & hp gaing over the 13J 4 rotors peripherals race engines. That's some of my 0.02 cents insights.

 

Anything can be done for the right price. I do not know how RB can make aluminum side housings but can we assume that a similar mould used to cast the steel housings were used to cast the aluminum ones? This does not mean that it was a piece of cake. This requires extensive work in terms of materials engineering, manufacturing processes, as well as feasibility. I somehow don't think that a small rotary aftermarket company can manage to do this on their own. My assumption is that these aluminum side housings were developed for racing with financial and engineering support from Mazda. Small numbers were then produced to public. I highly doubt the whole aluminum side housing project profitted. These are just my thoughts and assumptions.

Back to the 3 rotor idea:

I still believe it must start at Mazda. So lets say we have the eccentric shaft and intermediate housings developed. So we have the bare 3 rotor block all ready to go. What next?

Exhaust:
-Custom exhaust header - new exhaust header

Intake:
-What about the auxillary ports for the intermediate rotor? Leave them out? That would lead to fueling problems as each rotor is not receiving the same amount of air.
-New intake manifold. 20B ones will not work as the Renesis is a 6 port.
-New larger throttle bodies to support increased airflow
-Redesigned intake dynamics to support increased airflow

Electronics/Ignition/Fueling: I could write a book on this.
-Additional spark plugs, ignition coils.
-2 rotor ecu will not work - new ecu
-Drive by wire (electronic throttle) - again new ecu
-Additional fuel injectors
-New wiring harness to feed new electronics (ie. fuel injectors)
-New EGR valve
-New IAC/BAC valves
-New fuel rail, fuel lines, fuel pump

Oiling:
-More heat-larger oil cooler?
-Additional oil metering nozzles and redesigned oil pump with higher capacity.

Cooling:
-More heat - larger rad?
-More cooling passages requires higher output coolant pump.

Others
-New oil pan with larger size to support the additional oil capacity.

OK, I'll stop now.

 

only if we assume they are die-casting them and not sand casting them. i hope that they are die cast because that allows for higher temps to be used we means less of a chance for defects caused by air bubbles etc. also are they using "virgin aluminum" - recycled aluminum can have many other materials mixed in which can cause defects due to differences in cooling rates.

 

That would certainly be easier, but it isn't necessary. The current 20B from mazda uses two different thickness intermediate housings. One intermediate housing is the same as what is found in the 13B, the other is thicker. So a Mazda production 20B does not have equal spacing between the rotors.

On the other hand, many performance rotary shops have built their own version of the 3-rotor using a custom e-shaft and both intermediate housings the same as the 13B. The result of this is that you get a 3-rotor that is shorter than the Mazda production 3-rotor. I have no idea what cost is involved in this, but so many rotary builders have done this or something similar that it can't be THAT much more expensive. Some of these places even make custom 4-rotors....and Hurley makes a 6-rotor!

Here are some websites to such engine builders:

http://www.pineappleracing.com
http://www.hurleyrotary.com
http://www.hitman.hm (He isn't actually a builder but a tuner. His site gives contact info for his engine builder though.)

 

But even if you have the 3 rotor Renesis bare block complete (housings, e-shaft, etc.) you still have the many other challenges that I mentioned above.

I don't think you can use interchange 20B parts with a Renesis.

I don't know much about the 20B but assume that it is similar to the 13B.

The water seal o-ring grooves on the 13B are cut into the side and intermediate housings. On the Renesis, it's cut into the rotor housings. So if you use 13B/20B side housing with a Renesis rotor housing you would have a water o-ring groove on both sides. What about exhaust ports (there are no exhaust ports on the 13B/20B side housings)? Also, do the bolt patterns match up? Again what about the auxillary ports. Correct me if I'm wrong but all production 20Bs are turbocharged and do not have auxillary ports.

Even if you managed to create a 3 rotor from 20B and Renesis parts, you would still need to modify everything that I mentioned above.

You can see I am against the 3 rotor idea. The beauty of the rotary engine is its simplicity. The more we add to it the less simpler it gets.

 

Racing Beat has an RX-8 in their possession. The engine is currently on the dyno as they are engineering products for it.

 

I emailed racing beat and from what they said I don't think they have an 8 I will post the email when I get home. But in it I asked them if they had an RX-8 in house and the answer from how I read it said no.

 

ummm... what's the good word fritts?

 

Forgot to finish the post when I got home from work. I specifically saved the email from racing beat because of this thread too. Hopefully I remember and post it tonight.

 

Here's what RacingBeat sent me.


Sorry, but I can't confirm any current work on the RX-8. It is our intention
to offer parts for this car after its release, but we do not have a
timetable established at this time.


Best regards,

Jim Langer
Racing Beat, Inc.
714-779-8677
www.racingbeat.com

 

another thing to consider with a 3 rotor engine is that it is heavier. i don't mean it will significantly add weight and throw off the balance of the car. my bigger worry is that the engine is not as "rev-happy". the Cosmo's redline was a little lower than the FD...so what might it mean with the RX8? or even a new RX7?

i was seriously considering dumping a 3 rotor into the FD, but i love how the 13B just revs freely. kind of like driving an early miata (1.6 L) and a later one (1.8); the power is better but the feel is not as great. and with light-weight cars "feel" is a big deal.

although 300 HP without turbos is pretty nice. just gotta wait and see i guess

take care

santinp