Manifold porting questions.
Thread Starter
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Manifold porting questions.
Okay, I've got my flame suit on because I'm sure this has been covered a thousand times but there is nothing in the search. When you port the intake manifold do you port the full length of the runner? I can see where the ridges on the tube side have to be removed and I figured I should remove the bump in the side of the runner on the head side in order to eliminate the sharp turn but was wondering if I should do the whole thing. There was a post just a short while back on the plenum so I'm pretty sure I've got that covered. Any help here is appreciated.
Instructor
Joined: Mar 2005
Posts: 157
Likes: 2
From: Fayetteville Ga
Originally Posted by Morley
Basic porting would be to remove any and all sharp edges and obstructions, all the way through out the air passages. The BEST thing to do would be to then have it extrude honed...but that gets expensive.
Extrude honing will have the inner surface of your intake a very smooth mirror like finish. But it will cost several hundred dollars. It's worth checking into to explore all options.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Have you considered the siamese base mod along with porting the base??
Also I think the object is to have one smooth continuous flow from plenum to valve so matching the base to runner & to head would be a good idea.
Also I think the object is to have one smooth continuous flow from plenum to valve so matching the base to runner & to head would be a good idea.
Last edited by 65Z01; Oct 22, 2005 at 09:44 PM.
Thread Starter
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Originally Posted by 65Z01
Have you considered the siamese base mod along with porting the base??
Also I think the object is to have one smooth continuous flow from plenum to valve so matching the base to runner & to head would be a good idea.
Also I think the object is to have one smooth continuous flow from plenum to valve so matching the base to runner & to head would be a good idea.
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
Every little bit helps, I did some "mild "porting of the base, runners, plenum and TB. ET was unchanged but picked up almost 2 mph. That was with stock exhaust. Plenty of room for additional porting. Outside of some time and a little materials its essentially free hp.
Instructor
Joined: Apr 2004
Posts: 193
Likes: 0
From: peculiar mo
i did some mild porting on the plenum runners into the base also a little polishing and gained a couple of mph as well(in about a eigth of a mile). if i could do it again(need more time) i would take the heads off and match those up better
