I'm curious to know what all the holes are for in the intake. My intake is off my 93 camaro.

1st off, this one is hard to see in the pic, and easy to miss in real life. There is a hole in each intake runner. Pic is here :
http://www.aedctexas.com/cabinet/fil...uild%20044.JPG

2nd, I understand the allen bolts underneath were for the casting process. But what air moves through there?
http://www.aedctexas.com/cabinet/fil...uild%20032.jpg

3rd, The left side has four holes. Two thread directly into the plenum. One - the PCV grommet one pulls air from the lifter valley. Where is the fourth one plumbed? I blew in it and could not feel where the air was coming out. It is the hole on the furthest right in the pic.
http://www.aedctexas.com/cabinet/fil...uild%20035.jpg

4th, what are the two holes for that are just inside the TB opening? What is hole for that is in the center of the TB opening?
http://www.aedctexas.com/cabinet/fil...uild%20036.jpg

5th, if it hasn't been answered already, is the air in the plenum the same as the air below in the lifter valley? Because if they are seperate, then the front and rear seals of the manifold shouldn't affect intake air, right? You know, the famous intake leak.

Finally, can someone tell me which lines go where for this 93? I need to know where the brake booster goes, which holes are for the PCV, and which one is for the EGR. I looked on shbox's site, but it is for 94+. Thanks for the interest and help.

 

I'm sorry I cant see at all, can you post a better pic?
I THINK that that is the pcv intake side, the pcv valve iirc connects up to that with a rubber tube shaped like a U, I can check on my car tomorrow and post back then to tell you for sure.Idle air control, take a look at your throttle body and where that hole is on it.It sounds like you are asking if the intake air touches the air in the lifter valley, yes and no, for all intents and purposes the air in the lifter valley is not directly put into the intake so the intake gasket leak only makes oil leak out, however the pcv valve does suck air from the lifter valley and put it into the intake manifold, however the amount is quite small and not really affected by the intake gasket leak

 

I know those are vacuum ports at least for PCV, but could also be vacuum for all other external ports along side the intake. The later model intakes ('94-up I believe) have a port tapped at the bottom of the TB. The '95-up models used this port for PCV vaccum where the 93-94's used a vaccum port on the side of the intake right next to the PCV valve. When they changed to vented optis the side vacuum port was used for the opti and the PCV vacuum was then under the TB.

 

It's relatively the same... booster goes on the largest port on drivers side. I believe the smaller port on the drivers side is for EGR and the medium port is for PCV (as stated, the 180* bend hose).
On the other side you should have hoses for fuel pressure and accessory. Doesn't matter which ports you use.

 

So then brakes and egr are pulled from plenum, and the double pcv ports are routed to/from the lifter valley. Apparently the thread sizes are the same for two of those holes on the left side. So i was afraid that I put the wrong piece in the wrong hole. I guess it doesn't matter as long as PCV's are on bottom and EGR and Brakes are on top.

And now I understand the three holes up by the TB . In the center and out the two. The BBK tb I have bypasses that center hole and reroutes the IAC air to the other side of the blades. But my stock tb does not. Now I know... thanks.

 

I believe all vacuum sources are derived from the ports you see in the intake runners. Not sure if there's a '93 specific TB you should use? The port you see on the underside of the intake is plumbed for the PCV valve. The tin plate is a baffle for oil.

 

All years have the port drilled under the throttle body. Its just got a threaded plug in it on the 93-94 cars.

The first picture appears to be showing the tiny pinholes that are in each intake runner. Those distribute the idle air from passages under the manifold. I think the big hex plugs fill the holes that were used to drill the holes in the runners. The idle air and the EGR may mix in the passages under the runners.

 

http://www.aedctexas.com/cabinet/fil...uild%20036.jpg



I don't rightly recall, but using a "backyard" blow test from the front port of my intake I thought I remember air coming through the ports in the runners? If not, where is vacuum drawn for the exterior ports?