Question about the large hood scoop on the SS cars

[my68barracuda]

Certainly Chrysler did a lot of testing on those cars, but is there any known evidence that the large hood scoops on these cars really helped? Not that the scoop does not look tough, it does. It also adds a lot frontal area and wind resistance.
A Hemi running two carbs on a cross ram manifold is going to suck a lot of air and the surface area of the scoop is large so it does not seem like it would ever be pressurized if the goal was to add some passive air charging.
I understand the need to bring cool air into the motor, there are less 'wind resistant' ways to do that then the large forward facing hood scoop.
Also the cars of the same era, when running injectors would have the velocity stacks through the hood with no scoop.
The large hood scoops were ran for a reason on the carburetor cars, why?

 

[66fs]

They did and there was an area in square inches they needed to get the benefit. They knew what they were doing.

 

[mbaird]

How could a scoop that big NOT help ?
If nothing else it provided cool air .

 

[hemicop]

Chrysler did a lot of testing on the "mule car" Barracuda during development. When it was in private hands I had a chance to see some pics of it being developed & they tried IIRC, about 3 or 4 different designs. I love the scoop. But to be fair, it was later found out a "boundary layer" an inch or two above the hood surface was pretty much useless so the big scoop wasn't perhaps as effective as later designs. i.e. the snorkel scoop. Until the Demon Challenger came out it was the largest scoop Detroit utilized on a car.

 

[mbaird]

The boundry layer as I understand it is a dead zone that extends about 2" above the hood. So the SS scoop would extend above that layer and catch the airstream .
Am I interpreting that wrong ?

 

[hemicop]

You're right. My guess is in '68 the engineers were simply trying to cram as much air in as possible. Also, IIRC, there was a height limit on scoops in the S/S class so that played into it too. I've seen a "lip" added to these scoops right in-line with the opening attached to the hood to "push" (?) this boundary layer up & into the scoop in an effort (I guess) to make that air actually useful..... don't know how effective that is, but it's an interesting gimmick some guys tried....

 

[cojohnso]

And they only look right on an A-body?

 

[Yunick13]

According to the Shepard books, a hood scoop opening has to have 24 sq. inches to be considered effective, plus having it in the correct location.

 

[ns1rm21]

A couple of things here. We have all been driving down the road and have seen a bug or a leaf on our hood or windshield and it does not blow off….what your seeing is the “boundary layer. The car at speed is in a bubble of boundary layer or dead air and unless a hood scoop is above that it won’t grab any air.
Another reason for the big scoop is room for the carbs. Without the big scoop the carbs would not clear the hood and per class rules the carbs have to be in “stock location under the hood” so that means no hood scoop then no cross ram.

Another reason for the scoop is to let trapped air out of the engine compartment. Air goes in from under the car up into the engine compartment and gets trapped and the scoop lets it get out.

 

[mbaird]

Effective can mean a few things.
1. Forced induction
2. Fresh cool air
I can't verify that this scoop accomplishes the forced air function but it certainly provides cool air.

On my 78 Dodge motorhome I used 6" aluminum flex dryer ducting routed from the snorkel of the 440s air cleaner to the cowl . That lowered the engine temp noticeably during long summer trips.

 

[my68barracuda]

A couple of things here. We have all been driving down the road and have seen a bug or a leaf on our hood or windshield and it does not blow off….what your seeing is the “boundary layer. The car at speed is in a bubble of boundary layer or dead air and unless a hood scoop is above that it won’t grab any air.
Another reason for the big scoop is room for the carbs. Without the big scoop the carbs would not clear the hood and per class rules the carbs have to be in “stock location under the hood” so that means no hood scoop then no cross ram.
View attachment 1715878530 Another reason for the scoop is to let trapped air out of the engine compartment. Air goes in from under the car up into the engine compartment and gets trapped and the scoop lets it get out.

The observation that the carbs fill the height of the hood scoop answers the question on why it is so tall.