I'm about to put my RB header on and i was looking around. First of all what the hell are those square type arches in the 2 big exhaust ports for? and where are the 5-6th ports? all i c is 2 big ports and 2 small pencil size holes below each big port. I can see the acuators in all but where are the ports and what are the 2 very small holes below each big port for? I'm thinking about removing the 5-6th ports becuz i won't have enough pressure to open them anyway, and have heard they are a big obstruction.

 

Those are exhaust port inserts; they are designed to supress exhaust noise.

The 5th/6th ports are in the intake.&nbsp You'll see the actuators on the bottom of the intake manifold.&nbsp If you want to see them, you need to remove the lower intake manifold.



-Ted

 

thanks Ted. But aren't those exhaust inserts an obstruction to exhaust flow? So if those 5/6th ports are exhaust ports where do they open to? I don't understand where they get exhaust gases from and where they shoot them too. Are they another port on the housings, like another hole next to the exhaust ports? When i was looking into the exhaust ports i didn't see where the 5/6th ports shot the exhaust gases too, there are only 2 holes. shouldn't there be 4? 2 for the main exhaust ports and 2 for the 5/6th ports. thanks for your patience w/ a newb to the ports

 

Yes, they are.&nbsp Big power NA's run turbo rotor housings which do no have those inserts.

I think you're getting confused; the 6-port system is an intake system and has nothing to do with the exhaust.




-Ted

 

FWIW, those exhaust thingies are made of some kind of super metal. Many have tried and failed at grinding them out.

 

Here's a pic of a 6-port engine with the manifold off.



You can see there are six inlet ports on the cast iron plates (hence the name) and two exhaust ports on the rotor housings.

 

Yeah what are they for, sharpening pencils:

 

u got me there, i did think it was an exhaust port. Now everything makes sense.

 

damn, thats what i was going to ask next.

 

that and one more thing, do the TII housings have bigger intake ports since they don't have the 5/6th ports or do they have a better flow? Cuz if i was going to have a rebuild i might as well get all the goods u know!

 

MY goodness gracious, said Hailers. The approx one half inch holes below the large exaust ports are part of your emissions system. On a 87 model only one is open to the exaust manifold. Its for the EGR VALVE which on a 87 na is on top of the engine. The exaust gas flows thru the hole, thru a passage in the intermediate housing, to the egr valve. There is flow only when the egr is opened which the best I can tell from observing the voltage at the ECU, is during light acceleration. The other four holes are inoperable on a 87 na. They are covered by the exaust gasket. There is a hole in the exaust gasket for that ONE hole though. And like the man said, if you want to see the auxillary INLET ports, you need to take the intake manifold off. Just take you a few minutes. The best thing you can do is repair the actuators, the sleeves or which ever part of the aux port system that is broken. Those that can't, remove them. Those that can, repair them and make them work. Your choice. Step up to the plate.

 

The other two INTAKE ports are shown graphicaly in this url: http://www.goldcoastinspections.com/...ortdrawing.jpg

 

Rotor housings don't have intake ports.

Only peripheral port engines use intake ports in the rotor housings.

 

Go to http://www.iluvmyrx7.com and there you will find a FREE download of the factory service manual.

 

thxs for the pics, what i meant about the intake ports was , basically are the intake ports bigger on the TII vs the n/a? Since the TII doesn't have the 5/6th ports.