Orions98GT said:
when I was doing my PI swap I noticed on my stock plenum that someone prior to me owning the car tried to and it has a big line of skip marks were someone attempted to port it. I have a dremel in my garage and free time today. What bits would I need to port it? And what to what to smooth it out well?
What you need to do is find some bits and heads that are meant for grinding metal to remove larger amounts of surface material. There is an orange stone piece and some green ones I'm thinking of. They tend to work well, but I don't know their part number off the top of my head. Try to let the dremel tool do the work for you, rather than you doing the work yourself. Only in places where excessive material lies do you need to use extra pressure. Once you've grinded it down a bit, its time to smooth it out some. Using the sanding heads that Dremel makes will work great. Start with an 80 grit, then try the 120 grit. Again, try not to apply excessive pressure in one area more than another, unless if you need to remove more material in one spot. After you've grinded it down, and smoothed it out you can try using some sandpaper, or preferabley a sanding block to smooth it out. Go to the home improvement/building section of any good store and buy both a medium and fine grit sanding block. When I say medium grit, I mean around 120-180 grit. The fine sanding block should be no greater than a 250 grit, but you can get some as fine as 320 grit. Use the medium block, followed by the fine block. You should produce a really smooth finish. To finish, be sure to clean the piece up. Carb and choke cleaner works well. Spray out each of the surface holes, such as the ones for the IAC and EGR. You don't want any metal grit to be left when you install it and risk it getting sucked into the motor. If you wish, you can make it a bit smoother by using a nice metal polish, like mothers metal polish. I did this and made a mirror surface on the inside of mine. Though that can be time consuming.
Another option for polishing is to use dremel polishing compound with cotton heads, but its a little more tricky. If you apply even a bit much pressure in one area, it will produce a swirl effect in the surface of the metal. That, and when using a dremel tool inside the plenum, you run the risk of the choke scraping against the surface and putting a nice scratch in it. Its really up to you which route you want to take to polish it up. In the end, this can be a time consuming project. Depends on how far you want to go. I spent many hours working on mine. In the end, I got it to a flat and smooth finish that looked professionally done. I think it was worth it.
As for the throttle body, its not difficult at all to do. Best thing to do is to remove the throttle blade for easier polishing access. The stock casting isn't great, but definately not as rough as other surfaces. You should be able to polish up the throttle body by just using the sanding blocks I recommended above. A medium grit, followed by a fine gritt. When re-installing the throttle blade, be sure to get those screws tight. You do NOT want one falling loose and falling into the motor.
If you have any questions, just ask.
