Smoothing N/A intake

[Nationalmilkman]

Anyone ever take an N/A plenum apart? I am smoothing it all out and having it in pieces would be easier. Any ideas?

[mb3000]

Just curious, are you talking about the inside or outside of the plenum?

[Nationalmilkman]

I'll gasket match the ports later. I'm working on the outside. Taking off all the casting seams and thought about powder coating but might just paint it and I want it supper smooth

[Steve '92ES]

I've seen a few posts over the years where people have done it, but if I remember correctly most have regretted it.
There's a bunch of plastic inside, I think the runners might all be sleeved. Getting it all back together correctly is a major PIA.
At least that's how I remember reading it. Maybe someone who's done it can give you more details. Either way you might have been wise to ask before tearing into it.

[TUFFTR]

I've taken apart a few different year and model NA intakes (SOHC 12v, DOHC 24v and DOHC 3.5L 24v) and those plastic runners at the rear are weird. Some are (somehow) attached to the plenum, others are removable.

The only thing I have done and havent had the time or patience to do to put back together is the 6 butterflys in the middle. PITA to get out. bearing in between each one. They all needs come out to stop tiny bits of metal getting lodged in em' from sanding.

[Nationalmilkman]

I haven't tore it apart yet. So far I have just cleaned up the casting seams on the runners.

[dbest671]

I have taken the three sections apart on every one I have polished (outside). The plastic in the back pieces came right out. Just make sure after you are done sanding to clean the crap out of the insides. I never took out the butterfly part though, can't help you there. The actual runners are just aluminum, no sleeves.

If you are trying to get is super smooth, you might as well polish it.

[Nationalmilkman]

How hard was it to separate? I have the bolts out of the runners/butterfly section. I gave it a good whack on my bench but it didn't budge.

[dbest671]

Some are more difficult than others. You just need to break the seal, like trying to pull of the oil pan. I know I had a hard time separating the last one because I didn't want to damage the edge. A small thin blade screw driver and a small whack with a hammer was all it took though.

Or you could try prying it apart through the throttle body opening. Put a small piece of wood in there and give it a whack with the hammer.

[Nationalmilkman]

Thanks all it did come apart.

Polishing the plenum isn't going to fit my engine bay scheme.