Intake porting
 

Has anyone ever ported an intake manifold on an 86-88N/A? and if so is it fairly easy to do, and would you write up a little "how to" on it. Do you have to do the lower and upper, or can you just port the upper intake? And is it worth the time, what kind of HP gains did you get? Thanks in advance.

I'm in the process of doing it right now.. I spent maybe 2 hours on it, and I think I made a lot of progress.. I may spend another hour or so on it smoothing out anything else I can find. It's real easy to do...just make sure you get the right dremel bit. Whenever I find the power cord to the dig camera, I'll take pics..

There are a suprising amount of places that just LOOK bad.. ridges in the middle of nowhere, and whatnot.

I'm doing lower, upper, and a bit of the throttle body.... Anyone else port their TB? Did you actually widen the throttle holes? What did you do about the plates?

Hopefully, I'll have the car back together in 2 or 3 weeks.. see how it does.. ;)

-Tesla

its definitly worth it. My last NA i bought had it already done...I would like to see some before and after pics and while its being done if anyone has em.


-Daryl

Hey man! Where in Louisville are you?

While you're in there, you might want to consider matching the lower manifold to the ports. That will help cut down on turbulence and give you a little more top end power.

Are the ports bigger than the holes on the lower manifold? I don't want to cut the ports now--not gonna pull the engine this go around.. Maybe i'll trace them on paper, or compare them to the gaskets to see the size difference...

-Tesla

I live in Pewee Valley.. near Crestwood.. And go to UofL (speed). My car sorta stands out--it's blue with a damn white door handle..heh.. You?

-Tesla

I'm guessing, but I think the ports are bigger than the lower manifold. When I had an engine built, I had the intake ports polished and matched to the manifold. The builder did not want to do any porting. Since he didn't complain about the port matching, I can only assume it was all work on the manifold.

I think he told he he did it with ink. Put some ink around the ports, press the manifold against it and then see how the manifold matches up to the ports.

When I do mine, I'm doing what i believe is called gasket matching... just make all the holes that come together the same size as the gasket that seals them, or at least thats my understanding. There isnt really a point in porting any of the manifolds bigger than the biggest part in that particular runner anyways, since it would balloon out at the point where the two manifolds came together, then thin back out in the next part of the manifold... just stating what i'm seeing here, i could be wrong... :D I'd also like to know who has messed with porting their dynamic chamber/extension manifold connection, is there porting to be done there?


~Jesse

seems weird doesnt it skibum :) but it does work, you can even test it yourself without even touching an engine. make the ports at the end of the runners bigger and match on both manifold, you would be surprised at how much more air flow you get just doing this without making the middle any bigger, plus its the only way :)

easy test to see how it works, get a small coffee stirrer/straw, chew on both ends then with your front teeth make them round by just slightly biting them so their not flat, do this on both ends, first blow through it normal, then do this small experiment and blow through the straw then, much much more able to push air out, thats how i tested it :) hehe, i have too much time on my hands lol