Now the sump is in I can begin on the induction for real. The entrance to the throttle body is now pointing at the propeller end. This is fine in a tractor plane. I’m a pusher, so it is facing the wrong way!

The solution is a pipe shaped like a U turn. I needed to find out how gentle a bend radius would work and NOT hit the bottom of the cowl. This is about half an inch clearance. Yes a very tight bend. The air is slowed down by the expanding RAM air duct and then the filter inside the plenum. The turn is not a concern.

After the U turn we go into some pipe or SKEET hose, I’m undecided, and then to a plenum that will contain this air filter. I next needed to make a mold out of blue foam of the maximum size that would fit so I could work out where things were going. The angles and sizes can now be looked at.

I started by gluing some old foam blocks together.

After a bit of shaping I had my ‘maximum size’, big enough to hold the filter but not too big to fit under the cowl.

This woks with the bottom cowl on. I can also see now issues with the sump plug and a drain that has to go in. It may require a slight adjustment to the final size. I’ll know after I move a few things around on the sump.

To make the U turn pipe I grabbed an aluminium donut online, The idea is you cut this in half and you have your very tight radius pipe. Unfortunately it felt a bit heavy, so I’m going to use it as a mold for making a carbon fiber pipe.

First up I covered this donut in thin duct tape.

I’ve laid out one large ply of carbon on plastic with 8 diamond shapes to be cut after I wet it out.

Using an old cardboard box as a mount, this is a segmented two ply layup with peel ply. Next up is to cut the carbon down the middle, get it off the mold, clean it up and rejoin the halves. That’s the plan anyway.