Because I removed the air grille below the windshield to lower the roof, there is no fresh air ventilation for passengers. So I had to add some or enjoy the spectacle of riders turning into puddles of goo on hot summer days.
You would think that a simple ventilation system should be easy. Not!
It has taken me quite a while, but I have come up with a ventilation system that should work and that looks OK. You would not believe the number of different off-the-shelf things I looked at: boat cowl vents, clamshell vents, naca ducts, dust collection systems, and even shop vac parts. But either the parts I wanted would not fit, were only available from the US at extortive prices, or did not exist. Even the hot rod sites were no help.
Well, here are some pictures of what I came up with.
The front hole is an NACA duct to let fresh air into the cabin. I got the design parameters off the internet. It should work, but we won’t really know until the car is on the road. The insides of the duct will eventually be painted in flat black.
The two rear slots are to let the heat out from under the hood. They will have a sheet of flattened expanded metal welded to the inside of them to let the air through but hide the air intake box you can see looming inside the holes. The metal will be painted the same colour as the car.
Here is the inside of the sail panel showing the ventilation box and the 4″ tube leading to the dashboard vent.