Cowl or factory hood?? Can’t decide

[Erik the Awful]

That was my understanding as well. At speed air from your cowl hood is pushing back against the air trying to come through the radiator. The only place it can go is out the bottom of the engine bay. You're already pulling intake air from your fender, away from the hot engine air, so unless you've ditched the factory ducting and flipped your air cleaner lid for "moar powah", a cowl hood won't help your IAT.

 

[454cid]

That was my understanding as well. At speed air from your cowl hood is pushing back against the air trying to come through the radiator. The only place it can go is out the bottom of the engine bay. You're already pulling intake air from your fender, away from the hot engine air, so unless you've ditched the factory ducting and flipped your air cleaner lid for "moar powah", a cowl hood won't help your IAT.

I guess I should say that I have not done testing of any sort myself, but am extrapolating from what I've read.... well, and common-sense/real-world watching of IAT data on my scanner with regard to idle and moving.

 

[ralmo94]

Underhood temps bake the intake and iat sensor. Takes a lot of throttle and air flow to cool it back down. That's what I have noticed on my data logs. As far as keeping air from flowing through radiator, I haven't heard of that before. Seems to me that extra charge of fresh air would force the expelled heat from the radiator out of the engine compartment. Never seen any hard data one way or the other.

 

[dave s]

I think I like the factory hood repainted, cleared and buffed. I pulled my 94 up near the campfire last evening and was checking out the lines of the truck as it got dark. GM really did a nice job on these era trucks. I have a 2" cowl hood on my Nova so I know how cool they look. But I'm going to vote for the factory hood repainted. The trucks just look .....I don't know the right word but "just right" the way GM put them out. That's just my opinion. Looking at the little pics of the teal trucks in an earlier post I sorta liked the pic of the single cowl ram air cowl hood though....LOL!
Good luck with your decision.

 

[1998_K1500_Sub]

The finishing touch on a cowl hood is the use of hood clips...

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[Erik the Awful]

Seems to me that extra charge of fresh air would force the expelled heat from the radiator out of the engine compartment.

The problem is that the air has to have somewhere to go, and pushing air in the back of the hood means that the air in the radiator has other air competing to get out. We're fairly fortunate that we're dealing with trucks, and there's some ground clearance to allow the air out the bottom. I don't see how a cowl will aid getting the air out when it's in a high pressure area.

The best way to get hot air from the radiator out is to put extractor vents right behind the radiator, and ahead of the motor.

 

[ralmo94]

The problem is that the air has to have somewhere to go, and pushing air in the back of the hood means that the air in the radiator has other air competing to get out. We're fairly fortunate that we're dealing with trucks, and there's some ground clearance to allow the air out the bottom. I don't see how a cowl will aid getting the air out when it's in a high pressure area.

The best way to get hot air from the radiator out is to put extractor vents right behind the radiator, and ahead of the motor.

I don't see the pressure from the cowl over powering the pressure from a mechanical fan?
Right the air has to go down and put.
I'm picturing two drafts meeting and going down. The air entered in the cowl creating a venturi on the radiator air.
Wether that's how it works or not I don't know, but I've seen plenty of pictures of trucks with a cowl on this forum, has anyone said weather or not it helped or hurt cooling from experience?

Me personally I wouldn't put up the funds for one on my truck. This is just how I'm thinking it could be beneficial. Sitting still in a parking lot or traffic light, I could see it being very beneficial, but the question is weather or not it would be going down the road. I don't see it causing an issue. Jmho

 

[b454rat]

I've had alot of cars n trucks with cowl hoods, not one had any issues with getting hot. One truck I had could actually see the air go into the hood, lite snow actually. Had a 79 Malibu with a 4" Harwood and a nice 454, would sit at idle n not get hot. Nor going down the road. It had an electric fan, I would leave it off while going down the road, no need since the air going thru the rad cooled it. So if there was interference, restriction, whatever, would have noticed it then. I would think at low/no speed, it would keep it lil cooler under the hood. Hot air rises, and with the fan on, it would blow out the hood. It cant hurt too much, drag cars, salt flat cars still run cowl hood. Me, not overly worried bout the heat, just makes the truck look awesome lol.

 

[b454rat]

Mine

 

[454cid]

Are most cowl hoods even open, when they're just aftermarket add ons?