MARK
I built 2 plenums, one for each side. My reason was a quest for better efficiency. Won't go into them all.
You don't need to learn vacuum bagging or any elaborate lay-up techniques, unless you want work of art for all to admire.
I made mine with std Aeropoxy. It is good to a little over 300 deg when cured there and can use it everywhere else. I wouldn't use West because it's GT temp is much lower. I have heat soaked my engine in Texas September heat, no issues. The first, the left side was beautiful when first finished. I made a foam form and simple wet lay-up of glass/carbon on it. But, I then had to cut and trim to get clearance and add an oil cooler pick-up and now it looks as bad as the right one. For the next one, I just taped a cut cardboard soda case tray in place and laid my glass on it. Looks like ****, but it works great. For the sides I cut aluminum pieces to rivet/lay into the glass upper. The big thing with a plenum is you want a good seal with the inlet. If you are not going to do that then a plenum is not worth the effort, IMHO.
I was able to get 2 red tagged angle valve cylinders and made a simulated half engine to do cylinder wraps and engine layups. The wraps are important to keep the air inside the cyl fins all the way around. I made them with high temp epoxy and they are clamped to the cyl bases with band clamps.
My inlets are around half the area of stock and my cylinders are very well cooled. No louvers either.
Sorry I don't have a great deal of pictures. I am still working out a less than successful oil cooler experiment. Once I get all my mad scientist tinkering and data done I will post everything, including my top secret jet nozzle.
Right Plenum
Left Plenum
Early pass at cyl wrap, mark 1 if you will.
Simulated engine half
Dang! Dan beat me to it while I was trying to 2 finger type! If you want beautiful fiberglass, follow Dan's examples.