After some deliberation I decided to port and polish my own lower intake manifold with basic hand tools. While it’s not quite a stage 4 port… it’s pretty damn close so let’s designate this as a stage 3.5. The upper to lower ports are just shy of 40mm to match the gasket, but the lower to head ports are close to stock size. The reason for keeping the head ports the same is because I haven’t had the courage to port my heads yet. It doesn’t make sense to open it up any bigger at this time. I intend to port out a second set of heads in the future which I will port match a second lower intake manifold to a full stage 4.
To get started you just need a few of the following:
- Corded power drill. (Batteries don’t last long)
- 1/4″ extensions between 3-6″ long. Shorter the better for control and chatter.
- 1/4″ or 6mm shaft flap wheels. 40 and 120 grit. 1.5″ wide and 1″ wide
- Dremel with adjustable speed
- Dremel sanding drums of various sizes and grits
I used the 40 grit flap wheels to do the main shaping of the ports and the 120 grit flap wheels for a smoother finish. The 1.5″ flap wheel will cut out the upper port nice and evenly while the 1″ flap wheel can cut the lower ports and remove any of the casting imperfections.
To reach the center of the manifold I used the 6″ extension using both sized flap wheels from both ends. It works great at medium speed but if you run it too fast it wants to chatter due to the length of the extension. A 3″ extension would have sufficed for depth of this manifold.
The dremel with sanding drums was used around the injector port. The corners around the injector hump were too narrow for the flap wheels to reach, plus the high speed of the dremel can shapes the hump quicker. I opted for a modest reshaping of the humps because there isn’t much need with stock sized head ports.
I coated and installed the lower manifold. Eventually I decided to port out the lower to cylinder head area to match the gaskets better making this a complete stage IV port job.
To coat the manifold I used the following:
- 2x light coats of Duplicolor Ceramic Primer
- 2x light coats of Duplicolor Ceramic Ford Dark Blue
- 2x light coats of Duplicolor Ceramic Clear.
I wanted to complete the job in one go without waiting for the paint to cure for 1 week between each painting stage. By painting all three stages with 10 minutes between each coat and stage, I could complete it in one hour. To fully cure the ceramic paint I baked the manifold in the oven for 30 minutes at 250F, 24 hours after my final coat. And this was the result: