Between the idea to the finished result are about 4 months. It was the first attempt to work with positiv and negative forms.
I was scared when i saw the carb will get the hot air from under the bonnet. So I tried to keep the hight of the carb as low as possible to get enough space for a - whatever I will realize later to feed the carb with cool air.
I started with some easy models and with every try I looks a little better...
The version with the heating tube isolation was a good starting point.
Add a wood panle on top and bottom. Cover the isolation foam with a glas fiber tube, apply resin - a lot of resin - on it and smooth it with filling compound... and you know, that this is not a single task...
... until it is even. A coating with filler give a nice regular surface and can be polished.
The top half of the model looks over the laminated board. This is the first step to make a negative model.
Here are both halfes of the negative model in their raw form. Cutting the edges and polish the inner surface has to be done.
The two first positives are finished after a whole day working with resin. 4 layers of 160gr. glas twill fabric are enough to keep it stif and light.
Glueing both halfs together with 2 layers of GRP, smoothing the edge and ready for the first test in the car...
It fits nearly perfect...
The hight is so, that the lid closes easy. Only when the engine is pushe dto one side, the airbox rubs at the lid, but it is minimal.
A coating in shiny black will be the last step.
The lower support point of the airbox is a aluminium sheet mounted below the drop base of the Edelbrock 14" air cleaner. The filter element can be placed first and the airbox will press and seal it on the drop base.
The front end of the Marcos is like a shark nose - it will feed the radiator and now the airbox as well with lots of cool air. The gaps between the lid and the radiator are closed with aluminium sheets - so no air can escape - only through the radiator or in the airbox. The number plate will work like a spoiler and leads the air in the right direction.
At higher speed, maybe there will be a little overpressure to get the RAM air efect. I did not meassure it yet.
I placed a thermo element inside the airbox, an additional is outsode next to the carb. Both values compared shows, that the temperature inside the airbox is always the ambient temp ( here 10°C ), while next to the carb it goes up to 40°C.
At the moment I am on jetting the new Edelbrock AVS carb to get the best performance...