Reducing Air Flow to 5 1/4" RO Scoop

[Mike Gaines]

Here is a picture of my solution to reducing "additional un-needed" air flow into my 5 1/4" tall 66 Hemo RO Scoop. I needed this "tall" scoop to have room for my big INDY Single Plane Intake, 1" Spacer and Dominator Carb...but I did NOT need 189 Square Inches of Scoop Opening...so this reduces the scoop opening to about 52".
I had already drilled 10 1/2" holes in the right and left rear of the scoop let "extra" air out thru the rear of the scoop.
That setup with the full 189 Square Inches of opening performed well as I went 10.158 with it and the scoop wasn't wanting to lift of the hood and the hood wasn't wanting to lift of the car....but...I thought why have extra un-needed air going into to scoop, so this solution.
Car might go just a little, little better ET like this...who knows...but as I say "It makes me feel better" so be it.

 

[oldbee]

Now you’re getting into laminar flow characteristics of which I barely know how to spell. Looks /sounds good though.

 

[mikeyfrano]

Why don't you bring that metal up to the front of the scoop so you do t have all that turbulance in the scoop. Just a thought

 

[Mike Gaines]

Why don't you bring that metal up to the front of the scoop so you do t have all that turbulance in the scoop. Just a thought

I am not capable of fabricating something like that...lol

 

[dvw]

I wouldn't worry about it. I've run 5 years at 145+ with only 4 pins holding the hood. No holes in the scoop, carbs sealed to the hood. Never an issue.
Doug

 

[oldbee]

I wouldn't worry about it. I've run 5 years at 145+ with only 4 pins holding the hood. No holes in the scoop, carbs sealed to the hood. Never an issue.
Doug

Yeah but you have good “laminar air flow” lol.

 

[Mike Gaines]

I wouldn't worry about it. I've run 5 years at 145+ with only 4 pins holding the hood. No holes in the scoop, carbs sealed to the hood. Never an issue.
Doug

Carb sealed the hood is forcing all the air into the carb, none of it is trying to lift the scoop or hood off the car.
I can't seal my carb because the air horn of the Dominator sticks up ABOVE the hood line. No room for a seal as the carb sticks up into the scoop.
Anyway, I think it will all be ok. Thanks for your input.

 

[mopar 3 B]

How did you come by the 52 sq. Inches?
If that is what it really requires a foam scoop inserts should not be that hard to fabricate.

 

[Tex013]

I think you're starting to overthink it Mike . If you want to pick up some mask off your grill area


Tex

 

[dvw]

Make a drop base to seal it. something like Malex has.
Doug

 

[GITEX]

https://www.motortrendondemand.com/detail/air-filter-horsepower-shootout/0_f6zyfspf/
Just for reference.

 

[Mike Gaines]

Make a drop base to seal it. something like Malex has.
Doug

Like I said above....I can't seal the carb, even with a drop base, because the carb sticks up ABOVE the hood. A drop base will not rectify that situation....and...I don't want to remove my 1" spacer as it is important for my performance. Thanks. mike

 

[dvw]

Like I said above....I can't seal the carb, even with a drop base, because the carb sticks up ABOVE the hood. A drop base will not rectify that situation....and...I don't want to remove my 1" spacer as it is important for my performance. Thanks. mike

My front carb sticks through like yours. .030" aluminum was used to make the plate. The hood just pulls the plate down as it pretty flexible. The sides and rear has tapered foam cut to fit.
Doug

 

[Mike Gaines]

My front carb sticks through like yours. .030" aluminum was used to make the plate. The hood just pulls the plate down as it pretty flexible. The sides and rear has tapered foam cut to fit.
Doug

Dave....I would surecommend like to see 3-4 pix of it. Thanks Mike

 

[oldbee]

My front carb sticks through like yours. .030" aluminum was used to make the plate. The hood just pulls the plate down as it pretty flexible. The sides and rear has tapered foam cut to fit.
Doug

I shoulda took out a patent on mine 30+ yrs ago,lol. My carb wasn’t that high, but did the same as Doug with my 6-pak hood I had. Used a piece of extra foam to plug the opening when it wasn’t running(no air filter); one time I forgot to remove it,stalled out about 2secs later!

 

[Mike Gaines]

Dave....I would surecommend like to see 3-4 pix of it. Thanks Mike

I am begging for the pictures...I want to seal my carb.

 

[Mike Gaines]

How did you come by the 52 sq. Inches?
If that is what it really requires a foam scoop inserts should not be that hard to fabricate.

52 Square inches is what the opening is now......10" wide X 5.25" tall.
It was 36" wide and 5.25" tall.
There is no mathematical reason for 52 Sq Inches....it was just how I did it...My homemade carb "scoop/air dam" is about 10" wide so I have 10" of scoop opening to correspond to that.
Again...the scoop with the full 36" opening performed just fine (10.158 @ 131+mph) and the scoop didn't try to lift off of the hood...I just thought why not reduce the opening for "un-needed" air entering the scoop....car might go 10.157 rather than 10.158....lol.

 

[oldbee]

NOT an engineer by any means,but you do drive an air pump- in/out. Mine was fab’d to seal just outside the scoop opening. Give Doug a second, he’ll be back;sometime!

 

[mopar 3 B]

Required CFM=CIDxRPMxVE÷3456
CID. Cubic inches dispacement
RPM at max engine speed
VE. Volumetric efficiency at 85 percent

So for a naturally aspirated engine 392 cu. In. at 6800 rpm it requires 655.6 CFM of air.
Now if some how you can dermine what actually enters the carb throat you have it made.

 

[dvw]

The motor is out of the car right now. I'll take a pic of the plate tomorrow.
Doug