Cowl induction air cleaner
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Joined: Mar 2005
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From: Sunnyvale California
Cowl induction air cleaner
I've got a '73 with the cowl induction hood, and I'm putting the original air cleaner assembly back on.
My question is: Does anyone know what the two outlet/inlets on the air cleaner assembly are for? Are they supposed to draw in additional air from the engine compartment? Are they exhausts into the engine compartment to relieve excess positive pressure from too much air getting drawn into the air cleaner from the cowl?
I know the 1976 had a similar inlet which connected up to tubing to draw air from in front of the radiator, but as far as I can tell the 1973-1975 outlets just terminated in the engine compartment.
I stole a picture from a catalog (see below) to illustrate.
My question is: Does anyone know what the two outlet/inlets on the air cleaner assembly are for? Are they supposed to draw in additional air from the engine compartment? Are they exhausts into the engine compartment to relieve excess positive pressure from too much air getting drawn into the air cleaner from the cowl?
I know the 1976 had a similar inlet which connected up to tubing to draw air from in front of the radiator, but as far as I can tell the 1973-1975 outlets just terminated in the engine compartment.
I stole a picture from a catalog (see below) to illustrate.
Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
My 74 with cowl induction is exactly like yours......a duel snorkel inlet air cleaner drawing air IN from the engine compartment. The "cowl" supposedly gives more fresh air at WOT. If yours is like what's shown in the link then it is correct. Not sure if this answers your question or not.
Last edited by goinbroke; Jun 22, 2005 at 06:08 PM.
Instructor
Joined: Mar 2002
Posts: 140
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From: east hampton ct
The cowl induction is operated by a switch on the gas pedal linkage. Under normal use the cowl provides no air to the engine. A small electric motor operates a baffle in the hood which opens when the car is floored. Its easy to remove the baffle and motor so you get cold air at all times. Its debatable if the cowl alone provides enough air flow so that the aircleaner snorkles could be blocked off. I made inserts to block off the snorkles and couldn't detect any difference in performance but that still doesn't mean airflow was sufficient.
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Joined: Mar 2005
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From: Sunnyvale California
Aha, that explains my confusion. The motor and baffle are missing on my hood so it's drawing air all the time. Anyone know if the air pressure available through the cowl is a proportional to how fast you're driving, or does it make any difference at all?
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Joined: Jun 2005
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From: Rochester Hills Michigan
well typically the faster you are going the more air the engine will "vacuum" in to it. the engine will be the main regulator in how much air is drawn into itself. that is unless the air intake is so small that it will starve for air. assuming you have a 350, about half of the overall displacement is fuel, and the other half is air. so thats 175 in^3 of air / revolution. so at WOT (lets say 6000 revolutions/min) the motor needs 1,050,000 in^3/min now put that in the stantard units of ft^3/min (CFM)= 607.63 ft^3/min.
i dont know the math/physics for air flow threw a extruded rectangle.
i dont know the math/physics for air flow threw a extruded rectangle.
