Cowl Induction - Tilted Forum Project Discussion Community

leftturn109 · 08-02-2003, 02:40 PM

what does Cowl Induction do and how does it work

MadMartigan · 08-02-2003, 02:56 PM

I may be able to answer that one.

Cowl induction was a Chevy thing and it was found on the Chevelle in the late 60's and early 70's. Most traditional hood scoops pull air in from the front in sort of a ram induction style. Some engineer found out that the air at the windshield is cooler so a hood was developed that pulled air from the back of the hood by the glass. It was a small flap that was vaccum controlled and as the carburator created more suction the flap would open and pull more air into the breather.

I had a 1970 El Camino with a 327 that had this hood on it and i always enjoyed flooring the eccelerator and watching that flap open up. One thing i do know for sure is that i did not lose many races.

Since we have discussed this let me say that you will see some cars at the shows and the badge on the hood will say Cowl Induction but if it don't have that flap right in the top of the hood towards the back of the hood it aint the real thing.

WarWagon · 08-02-2003, 05:14 PM

Mad Martigan was close, aside from a few details. The thing about cowl induction was not so much about cooler air as it was, well, having air, and the ram air effect to go with it.

With a number of hood scoops available in that era, despite several of them being open and "functional", the truth is that they did absolutely nothing. In reality, the aerodynamics of the cars would cause the air to flow up and over the scoop, creating more of a vaccum than providing fresh air.

However, it was discovered that at all speeds, there is an area of positive pressure at the base of the windshield. As a result of this finding, the thought of putting a scoop or opening at the base of the windshield, or "cowl", provided fresh air under a positive pressure, which became more and more effective as speed increases.

Although the flapper is cool to look at, the more modern cowl setups alleviate the flapper, and people often construct a bottom pan to go under the air cleaner , with foam around the perimeter to seal it off from the underhood air.

08-02-2003, 02:40 PM	#1 (permalink)
leftturn109 Crazy Location: Olalla washington	Cowl Induction what does Cowl Induction do and how does it work

08-02-2003, 02:56 PM	#2 (permalink)
MadMartigan Crazy Location: Florida	I may be able to answer that one. Cowl induction was a Chevy thing and it was found on the Chevelle in the late 60's and early 70's. Most traditional hood scoops pull air in from the front in sort of a ram induction style. Some engineer found out that the air at the windshield is cooler so a hood was developed that pulled air from the back of the hood by the glass. It was a small flap that was vaccum controlled and as the carburator created more suction the flap would open and pull more air into the breather. I had a 1970 El Camino with a 327 that had this hood on it and i always enjoyed flooring the eccelerator and watching that flap open up. One thing i do know for sure is that i did not lose many races. Since we have discussed this let me say that you will see some cars at the shows and the badge on the hood will say Cowl Induction but if it don't have that flap right in the top of the hood towards the back of the hood it aint the real thing. __________________ Nice to be here, thanks for the invite

08-02-2003, 05:14 PM	#3 (permalink)
WarWagon Loser	Mad Martigan was close, aside from a few details. The thing about cowl induction was not so much about cooler air as it was, well, having air, and the ram air effect to go with it. With a number of hood scoops available in that era, despite several of them being open and "functional", the truth is that they did absolutely nothing. In reality, the aerodynamics of the cars would cause the air to flow up and over the scoop, creating more of a vaccum than providing fresh air. However, it was discovered that at all speeds, there is an area of positive pressure at the base of the windshield. As a result of this finding, the thought of putting a scoop or opening at the base of the windshield, or "cowl", provided fresh air under a positive pressure, which became more and more effective as speed increases. Although the flapper is cool to look at, the more modern cowl setups alleviate the flapper, and people often construct a bottom pan to go under the air cleaner , with foam around the perimeter to seal it off from the underhood air.