I really like the idea of insulating the intake manifold and ITBs from the heat of the cylinder head, and have been looking for a phenolic spacer for months, but there just isn’t anything available, and I can’t find any companies willing to make a small batch, and the raw material is both expensive and pain to work with, so I took a different route and picked up a nice sheet of fancy aircraft-grade Baltic Birch plywood.
Rather than trace the outline I needed, I just used an old intake manifold gasket as a template and dusted it with a light coat of spray paint. Sharp eyes will notice that this particular one is a smallport, and I am running a largeport, but the first one will probably end up going to a good friend, and I will make another for myself.
I started with a guide hole in the center of each hole and from here slowly worked up to size. I then used a hole saw for the ports and a coping saw to rough out the outside shape. Further filing and sanding with a drum sander got it nice and flat and smoother in shape. The inside of the ports is still fairly rough because I want to get it on the head for a port match, so I am leaving extra material to work with for now.
