1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Intake porting?

Thread Tools
 
Search this Thread
 
Old 10-31-04, 06:55 AM
  #1  
Junior Member

Thread Starter
 
79-r7's Avatar
 
Join Date: Oct 2004
Location: columbus oh
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
Intake porting?

Well i have a tool sickness so on the snapon truck yesterday i picked up a porting kit im not ready to tear down my whole engine yet as im new to rotary but is there any gains to be had by gasket matching the intake and smoothing it up some ? ty in advance o btw its a 12a all stock except for cat removal and custom 2 1/2 exaust (stock manifold tho)
Old 10-31-04, 08:38 AM
  #2  
Airflow is my life

 
Rx7carl's Avatar
 
Join Date: Aug 2002
Location: Orlando, Fl
Posts: 6,736
Likes: 0
Received 1 Like on 1 Post
Be very careful doing this. Definately do NOT match the primary ports. Also dont widen them. You can enlarge them slightly top and bottom, but just a little. On the Secondaries, you can match to the gasket but no further.
Old 10-31-04, 08:58 AM
  #3  
Junior Member

Thread Starter
 
79-r7's Avatar
 
Join Date: Oct 2004
Location: columbus oh
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
ok leme check and make sure im straight on this the primaris are the center ports right like i said im a roto newb by verry little how much are we talking like 1 1/16 inch and also what kind of power gains am i looking at or how far up the rpm scale is it gona move ty for ypur patince
Old 10-31-04, 09:27 AM
  #4  
Airflow is my life

 
Rx7carl's Avatar
 
Join Date: Aug 2002
Location: Orlando, Fl
Posts: 6,736
Likes: 0
Received 1 Like on 1 Post
Yes the primaries are the 2 center ports. What year manifold are you using? You'll get a little mid-top end power, and if your conservative with the primaries, you wont lose your low end. Actually if your new to this I would suggest just leaving the primaries alone for now and work on the Secondary ports. Also try and clean up the top end of the manifold (smoothe the bumps) but be careful as the metal is thin in spots and you dont wanna breakthrough anywhere.
Old 10-31-04, 10:04 AM
  #5  
Old [Sch|F]ool

 
peejay's Avatar
 
Join Date: May 2001
Location: Cleveland, Ohio, USA
Posts: 12,507
Received 416 Likes on 296 Posts
My intake manifold porting greatly boosted the low end. Note that porting also includes *adding* material where necessary.

To reiterate: DO NOT ENLARGE THE PRIMARY EXITS. They are too tall as it is for best flow, but there's only so much that can be done with ports that narrow. Making them taller will hurt, not help.
Old 10-31-04, 11:02 AM
  #6  
Junior Member

Thread Starter
 
79-r7's Avatar
 
Join Date: Oct 2004
Location: columbus oh
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
It's a 79 manifold leme see if i got all this info straight primary ports are to big stock so leave them alone except for a lil smoothing of the entrance secondairys ok to be smoothed and pnly mached to the gasket sound about right? im not new to porting ive done many ford and chevy heads and a few hondas im just new to the rotary for being a simple engine i find it to be quiet complex lol its very finiky ty for all your guys help and advice im going to listen to a lot more befor i actualy start this port job!!!
Old 10-31-04, 11:08 AM
  #7  
Suicidal Death Missile

 
lovintha7's Avatar
 
Join Date: Mar 2004
Location: Newport News, Virginia
Posts: 1,782
Likes: 0
Received 0 Likes on 0 Posts
How are you coming on your 12a ported intake carl?
Old 10-31-04, 04:02 PM
  #8  
Airflow is my life

 
Rx7carl's Avatar
 
Join Date: Aug 2002
Location: Orlando, Fl
Posts: 6,736
Likes: 0
Received 1 Like on 1 Post
79, that sounds about right.

Its comming along. Got 3 different plenum configurations to test and hopefully we'll be there.
Old 07-29-10, 01:45 PM
  #9  
Almost not rotarded

iTrader: (6)
 
JoeNoble's Avatar
 
Join Date: Oct 2005
Location: Troy, Missouri
Posts: 961
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Rx7carl
79, that sounds about right.

Its comming along. Got 3 different plenum configurations to test and hopefully we'll be there.
any update on this? any pics?
Old 07-29-10, 07:57 PM
  #10  
Moderator

iTrader: (3)
 
diabolical1's Avatar
 
Join Date: Feb 2002
Location: FL
Posts: 10,822
Received 307 Likes on 268 Posts
not sure what you were searching for, but in addition to the thread being 6 years old, Carl hasn't seemed to be on here for about 2, so i wouldn't hold my breath for an answer.

maybe you should just start a thread an ask whatever it was you were searching.
Old 07-30-10, 12:40 PM
  #11  
Boosted Soon

iTrader: (1)
 
Twilightoptics's Avatar
 
Join Date: Nov 2008
Location: Auburn, WA
Posts: 581
Likes: 0
Received 1 Like on 1 Post
I took an SA intake and just cleaned up the curb rash. I also ground out a bolt hole mold and welded in from the back side. Now all the ports are smooth. Didn't touch the primaries really. With the RB header and this intake my 30,000mile Pineapple 12a made 110RWHP. Better than stock but was hoping for more with all the work.
Old 07-30-10, 12:49 PM
  #12  
Boosted Soon

iTrader: (1)
 
Twilightoptics's Avatar
 
Join Date: Nov 2008
Location: Auburn, WA
Posts: 581
Likes: 0
Received 1 Like on 1 Post
https://www.rx7club.com/1st-generation-specific-1979-1985-18/carb-rebuild-sa-intake-swap-881627/

https://www.rx7club.com/1st-generation-specific-1979-1985-18/dyno-after-rb-header-sa-intake-mod-carb-tuning-891720/
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
mulcryant
2nd Generation Specific (1986-1992)
10
09-09-15 05:24 PM
doritoloco
New Member RX-7 Technical
7
09-05-15 12:41 PM



Quick Reply: Intake porting?



All times are GMT -5. The time now is 12:34 PM.