Re: What does anyone know about " heat extcracting hoods" ?
I'm not sure that air doesn't come out of the cowl at speeds. Sure, there is a high pressure area there, but there is a high pressure area in the engine compartment at well. It all comes down to which is the higher pressure area. No idea what it is on our trucks but in general it would be based on the angle and size of the windshield, the size of the grill, the blockage of the grill (radiator, ac, tranny or oil coolers) and the ability for air to get out of the engine bay (underneath the truck, out the sides if there are vents).
It's hard to just say it always operates a specific way when cowl hoods are used in such widely varied applications. I've always heard that a cowl forces air down into the engine bay but now that I think it through, that's in the situation where it is channelled directly into the intake of a carburated motor, which is in vacuum. I don't know that comparisons have been done where the air had to fight the air coming into the front of the engine bay directly. Kind of apples to oranges there.
Who wants to let off a smoke canister in their engine bay and film it for us? Please?
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