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drrbc · 12-28-2013, 03:57 PM

I'd read a belly pan can cause heat retention in the differential, exhaust, etc.

Granted, turbulent airflow is a good means of convection- but I doubt this is what the engineers at Ford had in mind for my F-150 (I would expect to see "fins" of some sort attached to vital structures to increase surface area).

Conduction of heat to attached structures would lower the overall temperature and increase surface area. This would help warm fluids and bring parts up to their operating temperatures, but after that is the increased surface area adequate to dissipate the heat OFF of the vehicle should the temperature go too high? Maybe- I don't know?

What if the main mechanism of heat dissipation is radiation? In that case acrylic, coroplast, the pink stuff (board) would all be bad ideas (though clear polyethylene probably would be ok).

How about this:
1. Fashion the under tray from aluminum.
2. Spray the top of the Al belly pan (the side exposed to the vehicle) with Krylon Flat Black 1602 (high absorptivity of long wave), and the bottom (exposed to the road) with Krylon Flat White 1502 (highest emissivity and reflectance). Before painting black, bolt or TIG some Al u-channel along the length to increase the surface area.
3. Drive your car/truck to normal temperatures. Stop, crawl underneath and map out the hot spots with your IR thermometer.
4. Clean and prep the hot spots and paint the bottom exposed surfaces of the hotspots (those facing the road) with the Flat White 1502.
5. Install the belly pan.

Testing may be a bit tough once the belly pan is on. I don't know what a string of thermocouples would cost. An option may be a string (along say 25-30' of a single Cat6 ethernet cable) of "one-wire" temp sensors ($3-4 per in packs of 10) that could just be super-glued to the hotspots. The ethernet cable could be run into the cab and DAQ done on a laptop.

Thoughts?

12-28-2013, 03:57 PM	#1 (permalink)
drrbc EcoModding Lurker Join Date: Feb 2012 Location: Houston Posts: 80 Thanks: 24 Thanked 19 Times in 12 Posts	Heat Dissipation with a Belly Pan I'd read a belly pan can cause heat retention in the differential, exhaust, etc. Granted, turbulent airflow is a good means of convection- but I doubt this is what the engineers at Ford had in mind for my F-150 (I would expect to see "fins" of some sort attached to vital structures to increase surface area). Conduction of heat to attached structures would lower the overall temperature and increase surface area. This would help warm fluids and bring parts up to their operating temperatures, but after that is the increased surface area adequate to dissipate the heat OFF of the vehicle should the temperature go too high? Maybe- I don't know? What if the main mechanism of heat dissipation is radiation? In that case acrylic, coroplast, the pink stuff (board) would all be bad ideas (though clear polyethylene probably would be ok). How about this: 1. Fashion the under tray from aluminum. 2. Spray the top of the Al belly pan (the side exposed to the vehicle) with Krylon Flat Black 1602 (high absorptivity of long wave), and the bottom (exposed to the road) with Krylon Flat White 1502 (highest emissivity and reflectance). Before painting black, bolt or TIG some Al u-channel along the length to increase the surface area. 3. Drive your car/truck to normal temperatures. Stop, crawl underneath and map out the hot spots with your IR thermometer. 4. Clean and prep the hot spots and paint the bottom exposed surfaces of the hotspots (those facing the road) with the Flat White 1502. 5. Install the belly pan. Testing may be a bit tough once the belly pan is on. I don't know what a string of thermocouples would cost. An option may be a string (along say 25-30' of a single Cat6 ethernet cable) of "one-wire" temp sensors ($3-4 per in packs of 10) that could just be super-glued to the hotspots. The ethernet cable could be run into the cab and DAQ done on a laptop. Thoughts?