I'm almost afraid to ask this because everybody talks about it so much.. but where are the engine "ports" and what exactly are they...and why do i alwasy hear that peoples 5th and 6th ports are stuck shut? Does it come stock with 6? any info woudl be great, or a link also
Thanx

 

6 port = NA
4 port = turbo

 

Stains answer leaves a lot unanswered.
I myself have often wondered the same thing....so I had a look at some photos and they confirm my suspicions.
Each rotor has two side inlet ports on the irons, opposite each other, the 1 thru' 4 ports. In addition, each rotor has an additional port, normally closed by a sleeve valve (sort of a tube with a hole in one side), providing earlier intake timing. These are the 5th & 6th ports. At a set RPM (3800?), actuators rotate these sleeves. The intake charge can now pass through the tube and out of the hole into the engine to provide better engine breathing, acting like variable intake timing.
Hope this helps. Dave

 

www.rotaryengineillustrated.com

Pictures do a much better job than words do. Explore that site, it has good info.

 

Thanx a lot for the info, illustrations, its greaty appriciated

 

Here's a question, why are the turbos not 6-port? Would the 6-port setup interfere with the induction?

 

Something to do with the velocity of the air traveling through an opening. If you look in the motor, the turbocharger would sit right about where the auxilary port (5th and 6th ports) actuators are. Would be kinda hard to squeeze it all in there.

 

hm......... so what if you got rid of the actuators? basically can you put a turbo setup on the non-turbo engine? Or do the 6-ports stop that. I know that you have to open up the spot for the oil line, but what about the ports?

 

The 6 port design us used to maximize velocity at low engine speeds to keep the torque high. As the engine speed increases, more air is drawn into the engine and the remaining two ports open up. This allows much more airflow, and a much later port closing for a longer intake event. In this way, Mazda tries to maximize the amount of power delivered on the high end without effecting low end torque.

As for the turbo question, there's no fundamental reason you can't turbocharge the 6 port engine. Be aware that the 4 port block flows better (more port area). I recommend installing a TII engine if you want to go turbo. But if you really want to turbocharge your NA, then see the FAQ at the top of this forum.

 

Yeah Aaron, I've been meaning to ask you if yours was a TII engine or N/A engine.

 

Secks.