Greetings.
After answering an auto to manual question and finding my "how to" from like 5 years ago, I have grown nostalgic and decided to write another DIY. This one will show how to portmatch the IM to the gasket, open up the throttle hole up if you have a BBTB, and polish the runners and remove casting flaws on a stock 1.8/2.0 RD Tiburon, but can be used on any car (even a Pony
) It's sort of a birthday gift for liz, and I've always wanted to do something like this.
OK, here's what you'll need:
-A dremel tool
-A cutting bit, stone and dressing (aluminum melts to the stone), 60-120 grit sanding cylinder attachment, polishing attachment, light wire wheel
-Nev R Dull (or other finishing compound
-Aluminum polishing compound
-A caliper (to help measure the bore)
-Permanent markers
-A toothbrush (for final runner cleaning)
-A good engine degreaser (carb cleaner works well too)
-A palm sander
-A good intake gasket
-320 wet sandpaper
-800 wet sandpaper
Obviously, remove the IM. If you don't know how to do that, stop, and do something else.
We polished the top part of the plenum, this is not necessary but does look cool. To do that, get some 60 grit, put it on a sander, and sand away all the flaws. Switch to 120, then 180, then 220. Wet sand 400, then 800. Use a good polishing compound, apply it to the parts that you want to shine, and use the dremel's polishing bit (not pictured, but it is a felt wheel, usually white) on it. Several coats may be required, I did two. It COULD be shinier, but it matches the strut bar's look, so I left it.
It will look like this:
I also ran the wirebrush once over the runners on the outside, as they were dirty. You don't really see this part too well, so I didn't go for a crazy polish here.
Next thing, take your caliper and measure your BBTB's opening. The one installed on Liz's car is an Rside 60mm. The measure of the hole on the IM was 57.5mm, so I had to shave off 2.5mm. Using the caliper, I made 8 marks on the IM in a circular fashion and proceeded to cut, using the template and some good-eye coordination to acheive an average of 61mm circle... well it's more of an ellipse, it's not EXACTLY a circle but the BBTB clears it (at WOT you cannot see the IM, whereas before you could). Don't forget to mount the spacer and using a 60 grit sanding drum match it to the IM. Use the same 60 grit drum on the circumference of the hole. Switch to 120 and finish it off. You could go higher, but I finished there and took a wire attachment to it. It's pretty smooth. You could also have used a file here and it probably would save you time. I misplaced my coarse file so I did the job with the cutting bit.
Here's a pic of the idea (I had allready ported 3 runners here, but the last one is the one you should be concentrating on)
Next, apply the gasket to the IM. Keep it steady (hold it in place, making sure that the bolt holes all lign up:I used a peice of chewing gum to hold it in place), and take your marker and then "fill in" the space between the gasket and the runner hole. Do this for all the ports, making sure the gasket DOES NOT MOVE, otherwise you'll shave the wrong spots.
Begin cutting using the cutting bit on all four ports. Don't concentrate on one spot, you'll create a dip. Just use it like a lathe, back and fourth, back and fourth. Try to get a rough shape, feeling the bore occasionally with your fingers. Remember, it's not about just adding a large step angle, you gotta take out material from about an inch inside the runner to make the transition as smooth as possible. Remove as much as the casting marks from the runners as possible. Here's a pic of it halfway done the rough
cut:
Once you have cut all the runners, match up the gasket again. Chances are, some spots may need more cutting. Mark them again, and keep cutting until the permanent marker is gone. Don't worry about overcutting too much, you could always cut the gasket a bit... I didn't have to, but under 1mm should be OK. Air doesn't like sharp edges, so I smoothed the top part where the injector goes.
This is the finished rough cut stage:
After the rough cut, put on a stone and be patient: Aluminum will collect in it, so use the dressing accordingly. Get all the roughness out, then attach a 60 grit sanding drum. As with the TB hole, go over the bore smoothly: This is the last time you can correct any bumps or dips (to handle dips, shave AROUND the dip, never in it) so take your tme. You may have to change your sand drum a few times. Keep feeling the bore with your hands, the goal is to make it smooth.
Here is a pic after 60 grit:
Do the same with the 120 drum. That should make it pretty damned smooth. 120 can remove smaller bumps and dips, so if it still looks like a mess, go back to 60 and reduce the dremel's speed (I used setting 5 out of 6 for rough cutting, and 4 of 6 for rough sanding, 3 of 6 for final sanding) Next, get some 320 wet sand and go nuts in the bore. Go as deep as possible... Liz made a passing comment that I was fingering the runner... a small "break" then took place
Get all that shit out of it, then once you're done that, attach the wire wheel and polish it all up. In this pic, the runner on the right has been polished (looks dull but it's VERY smooth inside)and the left one was done 320 awaiting the wire wheel
Do that for all the runners. After that, do 800-1000 grit wet sand.
You're done
BUT, be sure to get ALL the shit out of the IM. I put the TB opening in the faucet of the bathtub and let it rip. MY GOD was there a lot of crap in there... I then ran water up each runner, and used engine cleaner to clean out the runners with a toothbrush. Then I ran water through it all again.
The final result:
After mounting the IM, we took it for a spin. Just at WOT you could hear a sound difference, and the car definitely breathes better. I gotta convince Liz to get a new cone air filter.
The next step is to shave the head, port it, 5 angle valve job, and polish the intakes. Aside from the milling, I will do the rest myself.
Enjoy~
DIY Portmatching the IM gasket, and enlarging the TB opening (with pics)
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