Airflow and grille opening

[Damn True]

Subject: '68 Camaro

Hypothesis:
A radiator constructed of modern materials might not need as much grille opening to provide sufficient airflow to cool the engine.


What I'm thinking:
I'm wondering if it's possible to block off the grille opening on a 1st Gen Camaro and still get sufficient airflow to the radiator via the two 5"x15" openings in the lower valance.

With a larger than stock air dam there should be a significant high pressure area between the lower edge of the grille and the lower edge of the air dam. The 5"x15" openings provide a logical path for that air.

Supporting anecdotal:
Most modern cars have minimal grille openings in comparison to the average musclecar and far more restrictive airflow paths to the radiator, and out of the engine compartment after passing through the radiator. In fact many modern cars draw their cooling air from behind the air dam which is a low pressure area and should provide less potential flow and more turbulent flow than in the aforementioned hypothetical config.



Radiator opening in core support: 330sq"
Grille opening: ~160sq" (not counting deduction for turn signal housings)
Lower valance opening: 170sq" (combined)

[chicane67]

There has been a little though of my own on this subject. From the aero discussions of late, the idea of building a high pressure in front of the rad... and a low pressure areo behind the rad... along with a minimal opening, has pointed me to thinking about something like this:





This shows the late model thinking on how to build the duct to control the gross air flow into the rad... and how to keep the frontal surface a little slicker. And in the pictures above... its now a more forgiving material, so they can bump the nose without distorting the duct like it would if it were made of aluminum.

This is how the principals work:

[HarleyR]

That's the exact idea behind every piece of duct work in a stockcar..

[6'9"Witha69]

IIRC it is called the burble effect (been a while since reading my buddies UTI school books). that is why a lot of late model cars have overheating issues if the deflector gets ripped off the bottom of the core support.

[Damn True]

Burble or Bernoulli?

[6'9"Witha69]

I am pretty sure it is burble. We use the term in skydiving also so maybe I am confusing the 2.

[Damn True]

You skydive?

Geez, from the ground, that has to look like a Boeing 707 in a flat spin.

[CarlC]

The plane has to go twice as high to accomodate him.

[6'9"Witha69]

Good one. Yeah, I was an A licensed jumper. Been out of current for a couple years now after my 2nd daughter was born.

And when I was a student my instructors had to wear more coarse jumpsuits to slow their descent to match my rate.

Don't ask me about jumping from Cessnas either!

[chicane67]

Its Bernoulli... but burble sounds kinda right for the left hand club.

[TMat]

There has been a little though of my own on this subject. From the aero discussions of late, the idea of building a high pressure in front of the rad... and a low pressure areo behind the rad... along with a minimal opening, has pointed me to thinking about something like this:





This shows the late model thinking on how to build the duct to control the gross air flow into the rad... and how to keep the frontal surface a little slicker. And in the pictures above... its now a more forgiving material, so they can bump the nose without distorting the duct like it would if it were made of aluminum.

This is how the principals work:

I know this is an old post, but it brought up a question. If you already have the chin spoiler and then add the baffle directly below the radiator will they negate each other? Should you only use one or the other or both?