Heater

Car Builder Solutions (CBS) do a range of cabin heaters. AK recommend the HEAT3. This has two fan units that draw air in. As we have to draw air from outside the engine bay, it means having to seal the heater unit in a custom made box of some kind. I couldn't be doing with all that.

So I selected a HEAT7 device
that has a single fan unit.



All I have to do is seal of the back of the fan unit with a metal disk screwed into place.  I made two holes in the disk for the two wires that connect to the motor and sealed them with rubber grommets.


The unit has a flange that one can connect a large (75mm) hose.

I want to fit the unit so that is fully serviceable from the cockpit side. I'm not sure it will be removable from the engine bay side once the car is built.
First some L shaped ally bars cut and screwed to the front of the unit to create a flange.



Cut the hole in the bulkhead so the heater box will slip in and stop against the flange.
On the engine bay side, bond two 3mm steel strips, drilled and tapped for 6mm screws in the appropriate place for the drilled holes in the heater flange.
Paint it with POR/Hammerite depending on how much money you have left at this point to seal the metal.







On the heater flange, fit some draft excluding type strip so as to make it air tight against the bulk head. This stops fumes from the engine bay and keeps the IVA man happy.











The unit now fits from inside the cockpit.

We now need a hole in the bulkhead somewhere for the heater hose. I have made this at the top of the passenger footwell. As the body is suspended over the chassis on a wheeled frame, I positioned it exactly over the chassis and dropped plumb lines to see where everything will fit. I found that the top chassis rail (in the case of a GENIII chassis) comes to 39cm above the lowest part of the bodywork in this area. That means the hose connection must not be any lower or it will foul the chassis when the body is fitted.
So marking that out, and using a 75mm hose (for that is the size of the flange on the heater) we end up with a hole almost at the top of the bulkhead where it will enter the passenger footwell.

Hole made using a hole saw and the flange fitted from the cockpit side.

I will most likely fit a grill over that to stop it sucking in sweet wrappers or my wife's stockings.

The 75mm hose looks a bit OTT when it is fitted.

Maybe we could fit a reducer and have a smaller diameter hose to run to the footwell. But the heater manufacturer made the unit with that size so I guess we should use it.

We can also see here the satin black surface of the engine bay which looks quite ok when cleaned up.