Cap/Rotor/Ignition Wire

[454cid]

Some folks remove the seal at the rear of the hood in a misguided attempt to "vent hot under-hood air". Problem is, of course, that the back of the hood is in a high-pressure area when the vehicle is moving. Instead of venting hot under-hood air, outside air is blowing into the engine compartment (think about the "cowl induction" hoods--of course the air is traveling into the engine compartment.) Air coming into the engine compartment from the back of the hood raises the pressure in the engine compartment, which reduces the airflow through the radiator.

The secondary purpose of that seal is to keep water out.

I think I probably removed it when I pulled the plastic cowl cover off. I never thought about it impededing air through the radiator because of pressure.... I certainly don't need that, as I've got enough disadvantage already with the fan shroud removed.

 

[kenh]

Some folks remove the seal at the rear of the hood in a misguided attempt to "vent hot under-hood air". Problem is, of course, that the back of the hood is in a high-pressure area when the vehicle is moving. Instead of venting hot under-hood air, outside air is blowing into the engine compartment (think about the "cowl induction" hoods--of course the air is traveling into the engine compartment.) Air coming into the engine compartment from the back of the hood raises the pressure in the engine compartment, which reduces the airflow through the radiator.

The secondary purpose of that seal is to keep water out.

OK, I DO NOT disagree with you. In fact I agree. BUT, in the aircraft industry cowls are engineered to provide a high pressure low speed airflow through the cowl to promote better cooling. Yes I know two completely different applications but thought it might be found interesting.

Ken

 

[Schurkey]

cowls are engineered to provide a high pressure low speed airflow

That's exactly the point of "Cowl Induction". High pressure, low-speed air ducted to the inlet of the carburetor (or FI throttle body). In this case, it's not for engine cooling, it's to get high-pressure, ambient-temperature ("cool") air to the carb inlet.

But OEM "Cowl Induction" is always a sealed system, using rubber or foam gaskets to prevent high-pressure air from leaking into the engine compartment. Lotza hot-rodders miss that point; they buy the spiffy "Cowl Induction" hood, but don't make any attempt to seal it to the air filter/carb inlet.