2.8 exh manifolds - reasons to port

[fiero308]

I am selling a pair of ported exh manifolds (already sold) and thought the before and after pix might be of interest to some.  I have done a fair bit of porting and polishing and so on, and I have to say that these are the WORST manifolds I have ever seen for unnecessary flow restriction.  I am guessing that the ported ones will make a substantial difference just by themselves (I'm not patting myself on the head; ANYone could do this!!)
I am attaching a series of pix; sorry but I don't know how to put a bunch on one post so there are a few replies.  The "BEFORE" pix are all different ports; some show the "lip" at the flange plate and some show another "lip" (for lack of a better word) that is inside where the individual 'runner' joins the main exh pipe.  All of that can be ground out and can't HELP but be a HUGE improvement.  WOW.  They are TERRIBLE (stock) but that means you can get some free horsepower REALLY cheap, too, and that is a big      
This is a cheap and really easy way to perk up your engine, improve performance, gas mileage, driveabililty, EVERYthing!!!!  NO downsides here.  EVeryone with a 2.8 and stock exh manifolds should do this.   Probably two hours of work and then a big smile!!

First shot: excess metal and flow-obstructing lip at the flange where it bolts to the head.

[fiero308]

this is looking into the manifold; shows both the lip at the flange and then the stupid 'window' where the runner meets the main pipe.  This window is on cylinders 3,4,5 and 6.  1 and 2 (diff sides) are the start of the manifold so all they have is the 'lip' at the manifold plate/flange.

[fiero308]

Another huge overhang at the flange.  Bear in mind that I didn't have to be  fussy in picking these; EVERY one was equally bad!!!!

[fiero308]

ANOTHER big lip at the flange and then another 'window' inside.  All of these edges and steps are impediments to flow.  Smooth 'em out!!!!

[fiero308]

The lip at the flange is gone and smoothed out.  Right away, better air flow, less exhaust 'hanging around' in the cylinder because it couldn't/didn't get out in time........

[fiero308]

The flange lip is gone and the 'window' inside is smoothed out.  Same thing.  Let the exhaust get out (where it is supposed to go....? )

[fiero308]

At the top more-or-less center you will see a short line that is where the flange lip 'WAS'........  That is how thick the flange obstruction is......!!!
Flange lip is gone here and 'window' is gone too; smooth flow now.
The way it should come from the factory....... or at least closer to it.
You would almost think they were TRYING to make it run worse with the manifold like it was stock.........  yuch...
Anyway,
I hope this is some help to someone.  It is a very simple matter to port but you DO DO DO have to be a bit careful.  You COULD grind right thru the wall of the pipe if you don't pay attention.  It is kind of dirty, noisy work but the upside is that about 2 hrs can have a reallly nice payback!!!!!  Don't know if this would improve airflow so much that you might need bigger injectors or not........  maybe???
good luck with it!!!