Cold Air / Ram Air intake to a carb

Been thinking about this for a while and figured the good people at PHR could give some advice on the tech side of my idea. 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.

-Sefus  

That is exactly what a cowl hood does. The lower air pressure under the hood vs the higher pressure out side the hood causes the air to get sucked into the engine compartment. Cowl hoods don't work as well as a hood scoop but you don lose nearly as much aerodynamics.

Also there are cold air intake kits for carburetors and they mount where the filter usually goes and they use piping yo channel the air  

In the Sixties, it was thought cowl induction added 10hp, but Ram Air (forward facing scoop) adds 20hp.  Of course, you can't tell on a dyno.  But Mopar engineers found with airtunnels, that a scoop opening near the hood surface catches barrier air that's skipping up and down over the surface of the hood, which is why the Six Pack scoop they made, raises the opening like an old Pro Stock, catching air that flows more parallel to the ground.

W-30 4-4-2 Oldsmobiles, in 1967 thru 70 I believe, took air in from between the headlights and later from under the bumper.  It helped clean up aerodynamics, but the underbumper intake can scoop up water, debris, etc.

Now, to go a step further...there are carb shields, flat pieces of metal between the carb base and intake plenum.  This keeps hot air rising up from the intake from heating the carb bowl. I always wanted to investigate putting a V shaped air dam, with its point at the thermostat water neck, the open end facing the carb.

this would keep the hot air the fan pulls off the radiator, from running into the carb. Send it down the length of the valve covers, instead, and it'd create perhaps a lower pressure air pocket inside the V.  But maybe its too much work for too little effort.

If you use a carb spacer to increase plenum volume, it can also act as a heat block for the carb.  but, a V shaped lifter valley shield can keep hot oil from the lifters and pushrods from splashing onto the bottom of the intake and heating the air charge.