Anyone install hood vents?

Several years ago I installed a Poison Spyder vent on a previous TJ. I saw no difference in the engine operating temperature. What I did see was:

- the elimination of the hot start stumble that happened every Summer, when shutting of the engine and restarting it while hot (e.g. getting gas)
- a reduction in the hood temperature, i.e. the front of the hood would be so hot I'd have to open it with gloves.

The single biggest benefit was I no longer had to pop open my hood, to let the engine bay cool, every time we stopped for a quick break on the trail
 
The single biggest benefit was I no longer had to pop open my hood, to let the engine bay cool, every time we stopped for a quick break on the trail
You never needed to do that in the first place. Is it hotter where you wheel than in my local SoCal deserts where none of us would ever need to do that?
 
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You never needed to do that in the first place. Is it hotter where you wheel than in my local SoCal deserts where none of us would ever need to do that?

This Jeep doesn't have vents in the hood and I haven't gotten around to installing a heat barrier around the injectors. If I don't open the hood and let it cool, it will stumble when starting. At some point I'll address the root cause.
 
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Several years ago I installed a Poison Spyder vent on a previous TJ. I saw no difference in the engine operating temperature. What I did see was:

- the elimination of the hot start stumble that happened every Summer, when shutting of the engine and restarting it while hot (e.g. getting gas)
- a reduction in the hood temperature, i.e. the front of the hood would be so hot I'd have to open it with gloves.

The single biggest benefit was I no longer had to pop open my hood, to let the engine bay cool, every time we stopped for a quick break on the trail

Yes the WHOLE point of louvers is not COOLANT temps but the underhood temps that seem to be worse for some.
Great that it helped with your heat soak issues.
I can relate to the opening your hood as I was doing the same thing but I do have a V-8.
 
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Yes the WHOLE point of louvers is not COOLANT temps but the underhood temps that seem to be worse for some.
Great that it helped with your heat soak issues.
I can relate to the opening your hood as I was doing the same thing but I do have a V-8.

Mine definitely is on the worse side. Now that I think about it, I'm guessing that might be so because my LJ still has the original underhood insulation. There's a Golen 4.6 Stroker sitting in a crate in the garage waiting to be installed, so I'll likely add hood vents when install time comes.

I did consider a V8 swap, but have grown fond of the Rubicrawler. It also helped that I picked up the Stroker from a buddy for one heck of deal.
 
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I installed 2 louvers in mine. It was hotter than hades in there and I wanted it cooler. It did lower the heat quite a bit, but the real reduction of under the hood temp came when I installed a new and complete exhaust system front to back. My old exhaust was lacking the pre-cats, my new exhaust had them. That dramatically lowered the temperature under the hood. It also solved my check engine light issue. Do you need to lower the temp? No, probably not, but as I live in a damn hot climate, every bit helps. I suppose I should paint my rig white if I was looking to thwart every degree, but old Sol and I have come to terms. You can just see my louvers in the picture. I like the looks.

IMG_3549.JPG
 
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Mine definitely is on the worse side. Now that I think about it, I'm guessing that might be so because my LJ still has the original underhood insulation. There's a Golen 4.6 Stroker sitting in a crate in the garage waiting to be installed, so I'll likely add hood vents when install time comes.

I did consider a V8 swap, but have grown fond of the Rubicrawler. It also helped that I picked up the Stroker from a buddy for one heck of deal.

KEWL can't wait to hear about the STROKER and how you like it. I'd have had to do about the same amount of work to do the V-8 swap or the I-6 swap since I had a 2.5 4 cyl.

Unless you like the looks of the vents or hood panels I'd run it without first and see what it is like. Then if you need to add the vents.
 
No disrespect to anyone, just sharing info here...

There is a certain direction and a pattern to the airflow that goes through the engine bay. This pattern is selected by the engineers for uniform engine cooling and is important. It is also completely adequate for the cooling of the TJ, even in the hottest climates.

The hood vents don't really help with the cooling. Fortunately, the Jeep has a big tolerance for errors, so even though most people drill the hood and install the vents in "random", "I think this looks good and will work" areas, the Jeep still runs. Otherwise, you can actually mess it all up, making it worse.

How do I know this? I've experimented with this stuff, took pictures with infrared cameras with different flows and compared. Monitored the temperatures with OBDII... Managed to mess up the flow on my previous Jeep and quickly discovered that some some other vehicle (i.e. Tacoma) have even a smaller tolerance for mistakes.

Cheers
 
No disrespect to anyone, just sharing info here...

There is a certain direction and a pattern to the airflow that goes through the engine bay. This pattern is selected by the engineers for uniform engine cooling and is important. It is also completely adequate for the cooling of the TJ, even in the hottest climates.

The hood vents don't really help with the cooling. Fortunately, the Jeep has a big tolerance for errors, so even though most people drill the hood and install the vents in "random", "I think this looks good and will work" areas, the Jeep still runs. Otherwise, you can actually mess it all up, making it worse.

How do I know this? I've experimented with this stuff, took pictures with infrared cameras with different flows and compared. Monitored the temperatures with OBDII... Managed to mess up the flow on my previous Jeep and quickly discovered that some some other vehicle (i.e. Tacoma) have even a smaller tolerance for mistakes.

Cheers

Interesting. I can see how not having a shroud on the radiator could affect cooling but I am not sure how adding vents to your hood would have any affect upon this? Now as I am QUICK to point out to anyone that asks I am not the brightest bulb in the pack and lay no claim to such. So I'd have no idea how to do any of this type of testing nor have the equipment to do such tests.

I would have to ask though about when you screw things up like adding a V-8? Or stroker 4.0(4.7)? Or forced induction? As we all know when dealing with modifying anything on our rigs each action has a REACTION.

Can you explain how trying to remove underhood heat is a bad thing? I'm not talking about engine coolant temps but the temps under the hood. My temps had gotten so high that it melted some of the plastic parts on hoses I used fittings with plastic washers.
 
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I would have to ask though about when you screw things up like adding a V-8? Or stroker 4.0(4.7)? Or forced induction? As we all know when dealing with modifying anything on our rigs each action has a REACTION.

Can you explain how trying to remove underhood heat is a bad thing? I'm not talking about engine coolant temps but the temps under the hood. My temps had gotten so high that it melted some of the plastic parts on hoses I used fittings with plastic washers.
As an example, what if the transmission or even the transfer case is supposed to be cooled by airflow that you are allowing to escape through the hood vents. I'm not suggesting this is a real thing but it's an easy example. Sometimes when you stare too long at one part of a problem you forget about the big picture.
 
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Interesting. I can see how not having a shroud on the radiator could affect cooling but I am not sure how adding vents to your hood would have any affect upon this? Now as I am QUICK to point out to anyone that asks I am not the brightest bulb in the pack and lay no claim to such. So I'd have no idea how to do any of this type of testing nor have the equipment to do such tests.

I would have to ask though about when you screw things up like adding a V-8? Or stroker 4.0(4.7)? Or forced induction? As we all know when dealing with modifying anything on our rigs each action has a REACTION.

Can you explain how trying to remove underhood heat is a bad thing? I'm not talking about engine coolant temps but the temps under the hood. My temps had gotten so high that it melted some of the plastic parts on hoses I used fittings with plastic washers.

Removing heat from the engine bay is not a bad thing at all! You are right, however. If placed in the wrong spot, the vent actually can disrupt the flow of air and cause it to escape the bay too early, without cooling some parts of the engine. As a result, you end up with cooler spots in some places but hotter spots in others.
 
As an example, what if the transmission or even the transfer case is supposed to be cooled by airflow that you are allowing to escape through the hood vents. I'm not suggesting this is a real thing but it's an easy example. Sometimes when you stare too long at one part of a problem you forget about the big picture.

While I get what you are saying I'm not sure I totally agree. But yes I can say I have gotten to foucused on one problem and wasn't looking at the whole problem I've missed things.
 
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While I get what you are saying I'm not sure I totally agree. But yes I can say I have gotten to foucused on one problem and wasn't looking at the whole problem I've missed things.
I thought someone did some analysis on this but I have no idea where I saw it.
 
No disrespect to anyone, just sharing info here...

There is a certain direction and a pattern to the airflow that goes through the engine bay. This pattern is selected by the engineers for uniform engine cooling and is important. It is also completely adequate for the cooling of the TJ, even in the hottest climates.

Also, no disrespect but I'm calling BS.
To say that jeep spent an extra dime for an engineer to design proper airflow through the engine bay, especially on a wrangler is to stretch the imagination too far. I picture management saying "Put a shroud on it. Does it stay below 210*? Ship it out." On a Porsche? Maybe. On a Ferrari? Probably. Not a wrangler.

That said, I agree that improperly messing with things, you could make things worse.
 
http://oman4x4.com/hoodvents.htm#theory
There are probably others, but this one came to mind.

I can see Oman doing this. He has been around for a LONG time. Heck I remember him from back in the JeepUnlimted days. He had some interesting ideas and had great stories.

That guy determined that above the radiator and above the exhaust manifold were where the heat collected.

I think this was part of the reason why AEV came up with the hood that they offered with the vent right above the radiator.