Nissan swirl control valve...

Hi guys. I was reading about a device called the "swirl control valve" on the ka24de nissan motors. I know it has something to do with secondary butterflies. Can someone please help me understand what this is and it's fuction? Also, if possible, did the s14 240sx & obd 2 altima have this device. Any help would be appreciated. Thanks in advance.

Hi guys. I was reading about a device called the "swirl control valve" on the ka24de nissan motors. I know it has something to do with secondary butterflies. Can someone please help me understand what this is and it's fuction? Also, if possible, did the s14 240sx & obd 2 altima have this device. Any help would be appreciated. Thanks in advance.

I think it's a set of butterflys, one in each runner of the intake manifold. The purpose being to create more swirl for better mixing and more torque at low revs.
I think later model engines ditched them, so the benefit must have been marginal.

Oh ok. Just to get one more thing straight. Do you know if it was a second set of runners as well(that fed to the secondaries), or just a a second set of butterflies attached to the existing runners?

Oh ok. Just to get one more thing straight. Do you know if it was a second set of runners as well(that fed to the secondaries), or just a a second set of butterflies attached to the existing runners?

I found you a picture
http://www.angelfire.com/extreme/hawaiianhardbody/images/engine/SCV.JPG

From this webpage
http://www.angelfire.com/extreme/hawaiianhardbody/engine.html