true

i would love to see a turbo new generation RE, the side ports are just perfect for turbo a set-up ,this set up provides more flow with less overlap.

 

Yes, if either Hydrogen or Ethanol catches on as widely available pump fuel Mazda will make a turbo rotary again. The boosted only hydrogen renesis has already been shown, just not in the lease program like the dual fuel renesis.

We are getting a hydrogen fuel station at our local university here and they are paying a HUGE sum to have a Prius converted to hydrogen. Doh, my thought was shoulda asked Mazda about one of the dual fuel RX-8 they have had on lease in Tokyo since March 2006.

But I guess the yuppy-hippies thought a sports sedan was bad PR and converitng a hybrid (The wrong hybrid- hello Insight) w/ batteries leading to more strip mining is great PR and a way to spend more $$.

 

The zero overlap sideport rotary will do very well with the high boost possible w/ alternate fuels.

As boost and exhaust back pressure increase our rotories w/ overlap really take a dive in efficiency and have to run a huge exhaust housings to overcome this even at "low" boost/backpressures.

The midwest RX-8 guys need to start getting with the Ethanol and boost

 

e-85 and Bio-diesels are the future.

 

so clean :]
thanks for posting pics

 

dude, look past the size comparisons. instead look more at the differences in intake and exhaust timing specs between the peripheral and side port engines.
just think about that for a minute ...

 

when i said 5hp, thats with a full exhaust. i thought about that for a while. and while your more focused on the intake and exhaust timing specs you also need to look at actuall hp, thats where it all comes down to. the renesis is lacking hp for a what it has compared to the older 13b. on a similar size port, a peripheral exhaust 13b is capable of more hp, but mazda couldnt figure out how to pass emissions with it at that time. thats really the only reason mazda went with the side port, because they were able to make some hp and still pass emissions. not because it has more potential for power

 

this is from a recently aquired sae paper. thanks again! here are 3 things that the side exhaust ports were intended to address. another thing to consider is apex seal failure. how do you think apex seal lifespans will change when they no longer have to slide over a hudge exhaust port at high rpm?

 

Being it still has side exhaust ports and not peripheral exhaust ports I doubt FI will ever come into the picture and if i remember correctly it is more displacement but same compression as the renesis. I highly doubt the V8 guys will worry to much about this new engine. While Im glad to see Mazda still plugging away with it, It just gets less and less likely they will ever produce another car with the potential the 3rd gens have.

 

Mazda has come a long way from the last generation REW and even the renesis, sure the RE is a bit high on emissions and a bit low on power (in most factory N/A set-up). but theres a lot of new technologies applied to the new generation RE like direct injection and the side ports to give new hope for the RE future.

 

I wonder what will be the new overall weight of the engine. Making those side housing from aluminum should save a lot, the cast iron ones where heavier than they look.

 

Dumb question... is this bridgeported? Sure looks like it.

 

i think its a reflection

 

Reflection. No bridge ports, been disscussed and verified a while back.

~Mike...........

 

Ahh, now I see.. Lack of perspective and the chrome everywhere was playing tricks on my noggin. thanks

 

any new news on this motor?

 

I think this relates slightly to what someone said earlier, about high compression motors, being high compression, can't see any more horsepower because the psi compressed by the motor is maxxed... But diesel motors run 24:1 compression more or less and tonnes of horsepower can be had even if you consider diesel engines are 30% more efficient than gas powered vehicles.

You can always run a E85 rotary and I'm sure diesel has been used in a rotary, albeit a really big single rotar motor, and turbocharging just increases its potention acting as a displacement additive rather than some means of increasing compression....

 

A rotary is unique because not only are you compressing air but you are also flowing it. You can't just keep increasing compression in a rotary because you'll kill flow through the motor. The peak compression range for a rotary is roughly between 9.0:1 and 11.0:1 and there isn't much power difference between any of those ratios. Below or above this range however power falls off.

 

every motor is simply an air pump with a combustion process added. thats what felix did when he took nsu air pump and added combustion. rotarygod what do you mean when you say increasing compression will "kill" the motor? it just will allow more power to be extracted from from each hydrocarbon molecule. too low and efficiency is too low, too high and more air will leak past the seal faster which leads to huge pumping losses and put a very high amount of stress on the already weak apex seal. sealing in a rotary is its achilles heel. actually N/A diesel rotary motors are very rare if any at all because of that problem. only realistic way to implement diesel in the rotary is by FI without intercooler.

 

they have the presentation on the mazda site.
u may need flash on your computer to play it.

http://www.mazda.com/mazdaspirit/rotary/16x/

 

not to turn this in to a flame war (srsly), but e85 is a loser. Lower net energy, higher price. If we're going to move to an ethanol economy we're going to need to see a lot more efficiency in engines/cars, as well as the refining and distribution system- and that's just to break even.

Alcohol is good for performance and that green feeling, but it cannot in it's current state, replace good old fashioned petrol for much of the traveling public.

I agree with the sentiment that while this is a revolution in rotary engineering, i doubt it will have the potential of the 13b, re, and rew.

Also, i too want to see a side port engine go to the races.

 

What he means is that on piston motors the charge is simply compressed between the rising piston and the heads combustion chamber= very little movement of the charge once it is being compressed.

On a rotary the charge is compressed while it is being moved from the top of the motor to the combustion side and then entire charge has to slip through the slot in the rotor at the minor axis of the housing as it is expanding from being ignited (ignition advance).

If you make the slot in the rotor too small (raising compression ratio) you lose a lot of power trying to force it through the smaller slot to the combustion side of the engine during its initial expansion.

Even the Curtis Wright diesel Wankel rotaries used lower compression and spark ignition coupled with the usual timed direct injection because of this phenomenon. They could have changed geometry and gone with a higher compression ratio, but it would have lowered the high rpm capabilities.

You just can't push the charge through the slot in the rotor fast enough at high rpm.

 

That's a false line of thought.

Every engine is a repeating gun. The work comes from the combustion, everything else is just the details leading to good combustion.

Since I'm already here...

Set a rotor in a rotor housing about 40degrees BTDC (sparkplug side) and rotate it through to about 40deg ATDC. Notice that the mass of air has to be squeezed past the pinch in the rotor housing. Notice that the "tub" in the rotor face is where most of the airflow is going to be.

Now notice that the only effective way to increase compression is by making the tub smaller. This hurts the engine's internal airflow.

Additionally (and this is from personal "gut feeling") with the way the volume would have to be reached, the effective concentration of gases and the ability for the flame front to reach the end-gases would actually be hampered by making the tub shallower. Notice that Mazda played around with different tub shapes, trying to get the highest amount of the gases near the sparkplug area for the quickest possible burn. A quick burn means more complete combustion, less ignition advance needed (less negative work), and the faster the burn, the less likely it will detonate. (AKA "How come large bore/short stroke piston engines are more detonation prone than small bore/long stroke engines?")

This is why power doesn't go up with compression the same way it does with a piston engine. You *could* make the engines up to 15:1 compression but it would be a power loss.

Combustion is all-important.

 

There was a guy in NJ who's just moved to DR in his rx8 was a 400whp renesis running his own turbo kit w/ t04r making 400rwhp w/ aem meth injection kit tanked with 50/50 water / meth combo...he's been running that for over 2yrs and no problems...from what he told me is he's running a custom ignition setup, custom fuel system, and he's having custom apex seals made to run more boost... too bad he moved to DR I wish i took more info from him.

 

air pumps require at least two stages,for lack of better words, intake and exhaust. internal combustion engines require four, those last two and compression and expansion. if you cut off fuel and ignition to a motor, crank it a few times you'll see air goes in one hole and comes out the other. hence an air pump that does workeven if you could seal off both halves at top dead center by completely filling in the tub each section has its very own spark plug, hence flame front reaches both ends just fine without it.the only reason why in piston desiel engines compression isnt higher is because at some point the heads would blow off.