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  #46  
Old July 30th, 2018, 12:04
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Nimrod Nimrod is offline
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Re: Hood vents, scoops etc. Heat extraction

Quote:
Originally Posted by David_BNSF View Post
Those look pretty sweet!!! How was installation? Any pics of them from the bottom side of the hood?
From ehall's build thread:

Quote:
Originally Posted by ehall View Post
Engine bay temperatures have proven to be a problem. The coolant temperature hasn't hit critical temperature yet, but the hood itself has gotten extremely hot a few times, even to the point where rain water evaporates off within a couple of seconds. I looked around at various options for a while but couldn't really find anything I liked, then I found the Rugged Ridge vents for TJ and JK for $50 and decided to try them. They fit pretty well and seem to do the job. Not great quality (OMIX-ADA) but they seem to work alright for now.

The plan was to put one hole on the driver side of the hood over the exhaust manifold to let hot air out, and keep the passenger side closed to protect the ignition components. I also wanted to avoid putting the hole over the brake booster to avoid rust, while also avoiding the truss that runs through the middle of the hood metal. Several measurements later and I had the vents positioned in a spot that looked safe so I drilled for the screw holes, and then measured and marked a spot for the hole.



The hole could have been a little more to the drivers side. The manifold air temperature sensor is exposed, as is the warning switch on the brake distribution block. I will probably move the distribution block soon, and worst case I can probably move the air temperature sensor too. At some point I would also like to rig up a solenoid or vacuum diaphragm with a flap to close the hole when the temperature is low, but there's a fair bit of engineering involved in that.





The final product looks pretty good.



I've taken some measurements with an infrared thermometer and already noticed a dramatic amount of heat shedding. I drove around for an hour to get everything hot and the passenger side decorative vent only measured at 88 degrees, while the driver side vent with the hole measured 133 degrees. I was also able to put my hand on the hood and keep it there--warm but not hot like before. It really draws the heat out of the hood. Quality of the parts is kind of iffy, so I'm not sure how long it will hold up, but for now it seems to work alright.
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  #47  
Old July 30th, 2018, 12:07
Ralph77 Ralph77 is offline
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Re: Hood vents, scoops etc. Heat extraction

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Originally Posted by redbirdrunner View Post
To remove or not remove the under hood insulation. That is the question.
Quote:
Originally Posted by warrpath4x4 View Post
yours has insulation??
My '96 did but my '00 does not.
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  #48  
Old July 30th, 2018, 12:25
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Nimrod Nimrod is offline
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Hood vents, scoops etc. Heat extraction

Quote:
Originally Posted by David_BNSF View Post
Those look pretty sweet!!! How was installation? Any pics of them from the bottom side of the hood?

Here's a view of the bottom side of my hood with Napier vents installed.

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  #49  
Old July 31st, 2018, 04:59
Mach2nh Mach2nh is offline
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Re: Hood vents, scoops etc. Heat extraction

With being unibody we are missing something most cars have. Venting in the wheelwell. The front of the xj is more frame like than any other part of the rig. And many of us are plated as well. Has anyone tried drilling like 1” holes in less structural area to help give that air some place to go? Most cars have air come in the front and escape by going down and sucked out the gaps on the wheelwell.
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  #50  
Old July 31st, 2018, 08:51
redbirdrunner redbirdrunner is offline
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Re: Hood vents, scoops etc. Heat extraction

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Originally Posted by warrpath4x4 View Post
yours has insulation??
yes my 96 does.
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  #51  
Old July 31st, 2018, 12:13
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Boostwerks.com Boostwerks.com is offline
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Re: Hood vents, scoops etc. Heat extraction

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Originally Posted by Mach2nh View Post
With being unibody we are missing something most cars have. Venting in the wheelwell. The front of the xj is more frame like than any other part of the rig. And many of us are plated as well. Has anyone tried drilling like 1” holes in less structural area to help give that air some place to go? Most cars have air come in the front and escape by going down and sucked out the gaps on the wheelwell.
Yeah, I would recommend against that. The radiator air flow (the only air flow that matters) of most cars is designed to duct into the low pressure zone under the car.

What car have you seen that vents the engine bay into the wheel well? That would be a first for me. The air in the wheel well is very turbulent and wouldn't exhaust well at all.
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  #52  
Old July 31st, 2018, 18:30
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techno1154 techno1154 is offline
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Re: Hood vents, scoops etc. Heat extraction

My thoughts are, the vents in the wheel well were to facilitate brake cooling but I could be wrong. I usually see them only on performance vehicles.
There are some vehicles with what I would assume are engine room vents but they are above the wheel well.
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  #53  
Old August 1st, 2018, 08:45
David_BNSF David_BNSF is offline
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Re: Hood vents, scoops etc. Heat extraction

Quote:
Originally Posted by Nimrod View Post
From ehall's build thread:
Sweet, thank you. Ordered me a set to try them out.
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  #54  
Old August 1st, 2018, 15:39
Mach2nh Mach2nh is offline
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Re: Hood vents, scoops etc. Heat extraction

Quote:
Originally Posted by Boostwerks.com View Post
Yeah, I would recommend against that. The radiator air flow (the only air flow that matters) of most cars is designed to duct into the low pressure zone under the car.

What car have you seen that vents the engine bay into the wheel well? That would be a first for me. The air in the wheel well is very turbulent and wouldn't exhaust well at all.
“Vent” is maybe the wrong word makes it sound like it has duct work. Really its just a gap between the inner fender and the frame that allows air from the engine bay and well to exchange in some way. Just remember when working on the YJ the heat coming up from the wheelwell was well hot. On the XJ this seems to be greatly reduced.
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  #55  
Old August 28th, 2018, 17:33
David_BNSF David_BNSF is offline
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Re: Hood vents, scoops etc. Heat extraction

Do any of you guys have the Hyline Hood Vents? If so, what are some thoughts on them?
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  #56  
Old September 3rd, 2018, 17:33
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David_Bricker David_Bricker is offline
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Re: Hood vents, scoops etc. Heat extraction

I have them. I have long fought with high temperatures, and the Hyline vents are one of the things that have helped.


The kit included a full size metal template that was quite accurate. Their instructions are complete, and they do not take any any of the internal support for the hood.


David Bricker / SYR
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  #57  
Old September 6th, 2018, 11:34
cronin96 cronin96 is offline
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Re: Hood vents, scoops etc. Heat extraction

I've seen a lot of good ideas for vents to pull the heat but I'm thinking of adding the timed relay first. This year with more wheeling I'm getting the soak more often.
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  #58  
Old September 10th, 2018, 08:19
Rockwood Rockwood is offline
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Re: Hood vents, scoops etc. Heat extraction

Just spent Saturday wheeling at 4,000+' and 100* temps. New stock cooling, ZJ clutch fan, RodLovers.com 16x7 vents, coolant temps stayed around 215* with the AC cranked. Still warm, but never overheated liked it used to without the vents. Was also able to pop the hood without gloves on. Granted, it wasn't exactly pleasant, but this used to be something that was impossible in these conditions.
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  #59  
Old September 10th, 2018, 08:47
LLLux31 LLLux31 is offline
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Re: Hood vents, scoops etc. Heat extraction

I thought I already commented this but I don't see it. BleepinJeep.com has a set of vents for sale for $49.99. I ordered a set and will post pics once they come in.
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  #60  
Old September 13th, 2018, 20:48
cat-town XJ cat-town XJ is offline
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Re: Hood vents, scoops etc. Heat extraction

I had my exhaust "manifold" off to weld up all the cracks.
While it was off I put a ton of header wrap and also fabricated a sheet metal heat shield
Then I made a hood hinge spacer kit with longer bolts
I assume this has prevented any underhood temp problems
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