Cowl Induction

[Gary]

As most of you know, I have a Cowl induction hood on my truck. These hoods are great because they actually serve a function rather than just being cosmetic. On a corvette forum, there are some excellent posts on how the science of them actually works for those interested: http://www.corvetteforum.com/forums/factory-correct-resto/359465-what-function-does-a-cowl-induction-hood-serve.html

The best post: Y[i]a see, Tom, if you go to college, you can learn these kinds of things, and the business and liberal arts guys, well, they can read it out of car magazines. 😀 😀

Like Macster said, cowl induction takes advantage of something that is otherwise all bad. The windshield deflects air flow coming over the hood up and over the top of the car. This causes aerodynamic drag, but fluid flow being what it is, it also creates a region of high static pressure at the base of the windshield, where the relative flow velocity is essentially reduced to zero. This converts all of the dynamic pressure or energy in the flowing air into increased static pressure. Since this increased static pressure is higher than the static pressure under the hood, the air from the base of the windshield can flow forcibly under the hood to the carburetor venturis if a properly designed channel is available.

Cowl induction is superior to hood scoops. Hood scoops are for “show”, cowl induction is for “go”. Even if you “ram” the air through the limited open area of the hood scoop, you still have to have some kind of efficient plenum device that will declerate the flow and convert the dynamic pressure into static pressure which is the only thing you can really use anyway. Cowl induction is a way of taking something negative (parasitic drag) and turning it into a positive (cool, high pressure air at the carburetor) with no additional expenditure of energy. :smash:

[Modified by Chuck Sangerhausen, 12:55 PM 8/7/2002]
JmpnJckFlsh is offline Reply With Quote[/i]

^This guy explains it better than I ever could

EDIT: Thank you!

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[Andrew Button]

Chevyman, have you ever seen a cowl induction on a 70-72 Chevelles ? It takes that principle and puts its one step farther. There is a flapping door with a hinge in the hood that is actually on a vacuum pot, and going down the road when the gas is stopped that trap door with the fins in the back pops toward the windshield and ends up pushing air into compartment around the airfilter, so rather than going under the hood, goes in that trap door… Its just something one has to see in person to appreciate.

[Gary]

[quote=”andrewbutton442″ post=127543]Chevyman, have you ever seen a cowl induction on a 70-72 Chevelles ? It takes that principle and puts its one step farther. There is a flapping door with a hinge in the hood that is actually on a vacuum pot, and going down the road when the gas is stopped that trap door with the fins in the back pops toward the windshield and ends up pushing air into compartment around the airfilter, so rather than going under the hood, goes in that trap door… Its just something one has to see in person to appreciate.[/quote] Ah yes, Chevrolet really outdid themselves on that. I’ve seen it..it is perfection incarnate.

[Author]

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