Just curious, due to the flame travel problems wouldn't a smaller rotor be better at fuel efficiency?

Would a 3/4 smaller rotary engine been better in terms of efficiency with good power output?

Trying to figure out why they went with the bigger rotors instead of more smaller ones. Won't this be a problem on the 16x as well.

or is this backwards?

Rip

 

That's a valid point and I too would have thought say a tri-rotor (smaller individual rotors) more efficient than two larger rotors. But then, they might get better thermal efficiency by the greater mass of a larger bi-rotor. As we know, "rotaries typically consume more fuel than a piston engine because the thermodynamic efficiency of the engine is reduced by the long combustion-chamber shape and low compression ratio." -HowStuffWorks

 

Nope.

Thermal efficiency is one thing.

Second is that Smaller rotor has less power.

and the more rotor a motor has, the higher chance that something will fail.

Not to mention the more rotor you have you will need to have more fuel, more complex intake design, complex exhaust design, emission,etc.

3 Rotor exist because they dont have to give a crap about emission (racing)

 

I too would favor a smaller rotor in an attempt to boost efficiency. However the 16X has changed the geometry of the rotors. Yes they are larger but they are also narrower. There must be something going on with flame travel through a longer narrower rotor that goes against what was always previously believed. It may be some time until we learn what actually happens but if the engine actually gets produced one day we'll eventually learn what it did.

 

That's when you're going to try to port it again, huh?

 

I need another motor before I can port one again. I do have a set of intake manifolds that I'm playing with but nothing to test them on. At least, not yet.

 

you also have to factor in the size of the housing, a three smaller rotor that might be setup to have the same displacement as the renesis might weigh 50 more lbs

 

Of course all that depends on who you ask.

The Aixro is quite a bit more forgiving with detonation then it should be.

 

are the tolerances so tight that no one besides a giant company can fab up a new rotary design, or is it because of the licensing cost?

 

Mostly its a question of practicality. The market demand for a motor with the characteristics of a rotary are pretty limited. High output per mass with a penalty on fuel consumption. In karting the answer is 2 strokes. No emissions worries so far.

Bikes, ATV's and watercraft would be prime targets, but considering the level of 4 stroke technology the Hondas & yamahas of the world already had available, a wankel doesn't make much sense.

Kia entertained a wankel motorcycle but they realized the FIA and other orgs like the AMA weren't going to welcome a wankel with open arms so they abandoned getting into the bike market.

Bombardier (Rotax) played with wankels for a bit with intentions for snowmobile power but budget crunch hacked the program.

There are two wankels available for karts - the Aixro XR50 and the Parilla Rocket. The Rocket was developed on a budget of under $100,000, and is nearly identical to the Aixro. They both sell in the $5000 range, although in volumes the production cost is probably on par with an equivalent 4 stroke like the Biland.

 

they changed the shape of the bath tub

 

You forgot the 16x is also more round which adds to efficentcy.