Cold air / ram air into a carb

[sefus]

In my constant search for efficiency, I'm thinking about how to keep constant cold/clean air coming into the carb. An open air filter under hood is good till the engine heats up, then you are getting a heat sinked incoming charge temp. A hood scoop helps feed cold(er) air into the open filter under the hood at the cost of aerodynamics of the car itself which takes us to a cowl hood. The cowl I thought was designed to vent hot air out although recently I am reading that people think it’s to shove air in that hits the windshield then somehow moves backward under the cowled hood. I don’t see how that would work but OK.

So my thought is with all the cold air induction kits made for modern fuel injected motors that connects right to the throttle body, why couldn’t a carb guy run one of these intake tubes into a bonnet? I know others must have thought of and done this already, heck I did it to a 440 in a motorhome just using a snorkel air cleaner housing, dryer vent tubing and zip ties. I guess my real question would be why not to go this route? If you place the filter directly in the path of incoming air (behind your grill or removed headlight or anywhere it will get constant clean air) it couldn’t heat sink.

Thoughts?

-Sefus

 

[braveseal]

http://www.ramairbox.com/product.html

check this place,
I've used these before,a little price but made pretty well.

 

[blue missile]

Sefus,
since you mention aerodynamics, what sort of car are you going to put this on?
Most A bodies have the same drag coefficient as a refridgerator, mine included. A true isolated hood scoop directly connected to the carb will give you what you are after.

As far as the cowl setup goes, if it is isolated from the engine compartment,it is dealing with neutral pressure gradient. The air flows over the hood and then has to go over the windshield and over the top of the car. there will be a lower pressure at the top of the car and eddys where the inside corner is between the windshield and the hood. If the cowl scoop is open to the engine compartment then the forced higher pressure in the engine compartment will vent through the scoop. But if the scoop is only attached to the carb the engin's vacuum will pull fresh air in from the neutral pressure zone by the end of the scoop.

Hope this helps.
Andrew

 

[wigsplitter74]

I'm working on building an air tray under my scoop, it uses a square filter that measures like 10"x14" right under the scoop, had to get a lil creative due to the engine being offset one way but that's why right now it's just cardboard