With a bit more time this weekend I thought I would get back to cockpit cooling. I previously cut some slots in front of the window, which should be a high pressure area, but I needed to make some exits to allow the air to flow through the cockpit. I wanted to make some louvers for the windows, such that the air passing over them would help to draw the air out. I pondered quite a few options for this, but decided I would try to bend the window itself to make the louver shape. The first issue was to make sure that our heat gun would heat up the lexan sufficiently to put a set into it. Which, as you can see it did!
The next potential issue was the thought that if I cut a slot in the window, the remaining lexan would flatten out and lose its shape. I had no real way of seeing if this would happen so decided to ignore it! I then marked out the window with some tape. I decided to angle the slots such that as they progressed they got slightly wider. No real reason for this apart from I though it looked better that way!
Again I just selected a holesaw for the slot width. I left enough material between slots to make a reasonable sized louver.
Once cut they looked like this. The camera seemed it was going to make it a real struggle to photograph the lexan, so I can only apologise for the rubbish pictures.
I then warmed up the lexan with the heat gun and just bent the lexan with my hands. In fact I got slightly burnt, but the hope is a little heat now saves a lot of heat later!! This left me with some positive louvers as you can see below.
So, hopefully now with sufficient airflow through the cockpit, I turned my attention the source of all the heat, the exhaust. Previously I had a single skin of ally with some heat reflective material on to try to keep the heat out. So the plan is to try to stop the heat which can only be coming from the exhaust, from getting in. To do this I have made up a second panel, as below, with another layer of the heat reflective material. Then between the panels to use some heat insulating material.
Here you can see the insulating material. It reminds me of some types of exhaust wadding AND roof insulation. I have never used this particular type before so lets just see what happens. It is horrible to work with though, its easy to cut but a nightmare as it seems to give me a rash, similar to fibreglass rash. Although that seems to have stopped so hopefully with a bit more exposure I will get used to it.
I used the same material to insulate the fuel tank, to try to keep it a little cooler, and to try to stop the heat from just going around the centre section. I need to put another layer on the side of the tank, but just ran out of time. I should get round to this next week.
I then put some more of the reflective material, with its insulating backing, onto the tank. I think the fuel may have been getting warm at Brands so wanted to try to stop this. Obviously though, as it runs a return system, the fuel will get hotter as it circulates as it will conduct heat from the engine itself.
