Are cowl hoods open in the back? If so, how do you prevent water from going into the engine compartment, getting all over the distributor, etc? Do you even worry about it? Is a cowl hood any different in that regard than the power bulge hood with the plate off?

I plan on getting a U.S. Body 3.5" cowl (maybe the 2" indy cowl) for my 91 formula next paint job.

Thanks for helping me out with this--I am currently confused because many people have cowls, however, every time the subject of opening the power bulge comes up, someone says you'll get water all over the engine. I don't see how a cowl would be different.

 

I would say they are used for looks, and for cars with larger engines ....

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1992 z28 25th Anniversary
All black w/ z28 wing
Flowmaster Exhaust
350 TPI

 

I know that. Yes, you also buy a cowl if you need hood clearance for some reason other than a larger engine. What I want to know is if they let water in and if it matters. I have seen one car with a cowl hood (3rd gen camaro) around here in the last few months, so I don't really have a lot of opportunities to ask people when I see them.

 

water will drip in stock hood or after market.....so whats the difference

just when you install plug wires...use dieletric grease to seal them

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98 z28 leather seats
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"wonderbar"
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cowl hoods act sort of like cold air induction...
A vacuum is created at the rear of the cowl (near the windshield)when moving forward (ever see leaves being pulled along by cars in the fall? same deal) so that outside air is sucked into the engine compartment. If your intake is sealed in an air box, the cold air effect would be greater i would think... this is more effective at higher speeds because there will be a higher vacuum.

That's my understanding of them, someone correct me if i'm wrong

[This message has been edited by HamsterOnaMission (edited December 07, 2001).]

 

Yeah, Hampster you got it. That's why they are called Cowl INDUCTION hoods. They're not just for bigger carb spacers or other clearance issues or even for looks. They were origionaly created to bring in cold air.

If you've ever seen a '69 Z28 (Cross-ram, yeah my friend's grandpa is luckey enough to have one) there is a solinoid that opens the vent when throttle is applied. The air cleaner also makes an air tight fist against the hood so all the air comes from the cowl, this way no water can get in at all.

-Matt

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I aint for sure with this...but that rubber gasket that is on the the car where the hood shuts will keep the water out or most of it. Also the cowl hugs the window pretty close. I know where you coming fron I have/had the same ? before. Good luck with your choice

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1989 RS Camaro
305ci TBI
Mods:
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3inch catback pipe
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Most functional cowl induction hoods have a lip that extends over the back which helps prevent rain water from falling straight in. When the car is moving, the air entering the cowl isn't moving fast enough to carry rain in with it, so it's not a problem.

 

Never had a water problem with my hood yet. Now those T Tops are anothe story. And yes cowls force air in a circular motion from the windsheild down to the front air dam under the car and back over the top. Add a K&N open air filter and you can add power too.

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86 Camaro Black SS Coupe, T Tops, ASCD Daytona Twin Turbo hood, Flowmaster, Custom Black Paint, Dunlop Road Kings S/R tires, Wheel Country Directional Chrome Wheels,new charcoal & gray interior including seats and door panels, leather wrapped steering wheel, shifter and emergency brake, new carpet and headliner, complete front end suspension rebuild, new Valve seals, and more mods to come
'91 RS 5.0 TBI = Waiting to be modded, but has all of the toys inside.

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It's not a higher vacuum at that point, but a higher pressure zone. The higher pressure zone is created where the air meets the windshield at the base. This higher pressure air enters the opening forcing it into the open element. Since it is a higher pressure than the underhood area. If it were a vacuum at that point it would be a cowl air "extraction" hood, since the lower pressure would suck the air out of the under hood area.

 

well if there is a vacuum under the hood, and high pressure outside the hood, air would be drawn in... if there was low presure outside, and high inside, then it would be cowl extraction....
Both vacuum and presure at the windshield are factors

 

Basic fluid mechanics dictates a high pressure area at the base of the windshield. The steeper the angle of the windshield, the higher the pressure (aka stangnation pressure). Since air is drawn into the cylinders from the vacuum created by the down stroke of the piston (excluding forced induction systems of course ), the greater the differential, the greater the benefit. In order to take advantage of this, a cold air box must be used.

Miles

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88 427 Big Block Camaro
(Best 1/4) 12.18 @ 113mph 1.75 60ft
(Best 1/8) 7.76 @ 94mph 1.72 60ft

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