2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Why are there archs in the exhaust ports and why exactly do they call em 6-ports?

Thread Tools
 
Search this Thread
 
Old 05-01-02, 08:27 PM
  #1  
Adaptronic Distributor
RX7Club Vendor
Thread Starter
iTrader: (12)
 
Turblown's Avatar
 
Join Date: Dec 2001
Location: Twin Cities, MN
Posts: 7,066
Received 91 Likes on 77 Posts
Question Why are there archs in the exhaust ports and why exactly do they call em 6-ports?

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.
__________________
Rotary Performance Parts


Old 05-01-02, 08:30 PM
  #2  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
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
Old 05-01-02, 08:59 PM
  #3  
Adaptronic Distributor
RX7Club Vendor
Thread Starter
iTrader: (12)
 
Turblown's Avatar
 
Join Date: Dec 2001
Location: Twin Cities, MN
Posts: 7,066
Received 91 Likes on 77 Posts
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
__________________
Rotary Performance Parts


Old 05-01-02, 09:02 PM
  #4  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally posted by 1Revvin7
But aren't those exhaust inserts an obstruction to exhaust flow?
Yes, they are.&nbsp Big power NA's run turbo rotor housings which do no have those inserts.

So if those 5/6th ports are exhaust ports where do they open to?
I think you're getting confused; the 6-port system is an intake system and has nothing to do with the exhaust.




-Ted
Old 05-01-02, 09:05 PM
  #5  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
FWIW, those exhaust thingies are made of some kind of super metal. Many have tried and failed at grinding them out.
Old 05-01-02, 09:08 PM
  #6  
I'm a boost creep...

 
NZConvertible's Avatar
 
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes on 8 Posts
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.
Old 05-01-02, 10:09 PM
  #7  
Full Member

 
ka8legend's Avatar
 
Join Date: Oct 2001
Posts: 231
Likes: 0
Received 0 Likes on 0 Posts
Re: Why are there archs in the exhaust ports and why exactly do they call em 6-ports?

Originally posted by 1Revvin7
all i c is 2 big ports and 2 small pencil size holes below each big port....what are the 2 very small holes below each big port for?
Yeah what are they for, sharpening pencils:
Old 05-02-02, 07:55 AM
  #8  
Adaptronic Distributor
RX7Club Vendor
Thread Starter
iTrader: (12)
 
Turblown's Avatar
 
Join Date: Dec 2001
Location: Twin Cities, MN
Posts: 7,066
Received 91 Likes on 77 Posts
Originally posted by RETed

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




-Ted
u got me there, i did think it was an exhaust port. Now everything makes sense.
__________________
Rotary Performance Parts


Old 05-02-02, 07:56 AM
  #9  
Adaptronic Distributor
RX7Club Vendor
Thread Starter
iTrader: (12)
 
Turblown's Avatar
 
Join Date: Dec 2001
Location: Twin Cities, MN
Posts: 7,066
Received 91 Likes on 77 Posts
Originally posted by Aaron Cake
FWIW, those exhaust thingies are made of some kind of super metal. Many have tried and failed at grinding them out.
damn, thats what i was going to ask next.
__________________
Rotary Performance Parts


Old 05-02-02, 03:51 PM
  #10  
Adaptronic Distributor
RX7Club Vendor
Thread Starter
iTrader: (12)
 
Turblown's Avatar
 
Join Date: Dec 2001
Location: Twin Cities, MN
Posts: 7,066
Received 91 Likes on 77 Posts
Re: Re: Why are there archs in the exhaust ports and why exactly do they call em 6-ports?

Originally posted by ka8legend


Yeah what are they for, sharpening pencils:
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!
__________________
Rotary Performance Parts


Old 05-02-02, 05:19 PM
  #11  
HAILERS

 
HAILERS's Avatar
 
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes on 19 Posts
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.
Old 05-02-02, 05:30 PM
  #12  
HAILERS

 
HAILERS's Avatar
 
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes on 19 Posts
The other two INTAKE ports are shown graphicaly in this url: http://www.goldcoastinspections.com/...ortdrawing.jpg
Old 05-03-02, 04:23 AM
  #13  
Super Newbie

 
Felix Wankel's Avatar
 
Join Date: Feb 2001
Location: Birmingham, AL
Posts: 4,398
Likes: 0
Received 1 Like on 1 Post
Re: Re: Re: Why are there archs in the exhaust ports and why exactly do they call em 6-ports?

Originally posted by 1Revvin7


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!
Rotor housings don't have intake ports.

Only peripheral port engines use intake ports in the rotor housings.
Old 05-03-02, 05:42 AM
  #14  
HAILERS

 
HAILERS's Avatar
 
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes on 19 Posts
Go to http://www.iluvmyrx7.com and there you will find a FREE download of the factory service manual.
Old 05-03-02, 07:43 AM
  #15  
Adaptronic Distributor
RX7Club Vendor
Thread Starter
iTrader: (12)
 
Turblown's Avatar
 
Join Date: Dec 2001
Location: Twin Cities, MN
Posts: 7,066
Received 91 Likes on 77 Posts
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.
__________________
Rotary Performance Parts


Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Skeese
Adaptronic Engine Mgmt - AUS
65
03-28-17 03:30 PM
msilvia
3rd Generation Specific (1993-2002)
28
04-14-16 12:58 PM
Engine stand ready
New Member RX-7 Technical
3
08-14-15 10:26 PM



Quick Reply: Why are there archs in the exhaust ports and why exactly do they call em 6-ports?



All times are GMT -5. The time now is 12:22 PM.