Different Strokes for Different Folks JK Wrangler Hood Vent

Ah well I have the 3.6 and am not all that familiar with the older engine layout.

I do not have before temps but to wouldn't be a difficult thing to get. Similar rigs running for similar times would net the desired info.


As for snorkels do you monitor your ambient vs intake temps? I just started and the intake is quite a bit warmer even with a snorkel
 

JKU87

Adventurer
What a great idea. I love DIY mods and this is a great example of one. Also love the bedliner and that has been sitting on my bucket list since i tore out my JKUs carpets two years ago. Great work.
 

mmaattppoo

Adventurer
I regularly monitor intake temps using an MX OBD II Bluetooth scaner adaptor and the Torque app on my Android phone.

A couple of years ago I installed at Rugged Ridge XHD low snorkel with the low intake. Intake temperatures are warmer than I expected after the install during prolonged low speeds driving due to the 3" aluminum section of the snorkel tubing being routed about 2" away from the exhaust manifold on the right side of the engine. At a gallop this issue is a non issue.

Intake temp ranges are as follows:

Stop and Go Traffic (Before) were 38°C - 66°C (100°F - 150°F)

Slow Going Offroad (Before) were 55°C - 93°C (130°F - 200°F)

Stop and Go Traffic (After) were 27°C - 49°C (80°F - 120°F)

Slow Going Offroad (Before) were 49°C - 66°C (120°F - 150°F)

Note1: these temp ranges are for summer ambient air temps of between 22°C - 40°C (72°F - 104°F); as reported by my Jeep's onboard temp sensor. I have seen an intake temp as low as 0°C (32°F) driving the Coquihalla Connector (a high mountain pass) in the winter with ambient air temps of -20°C (-4°F).

I'd be curious to hear about the intake temps with your setup on a Pentastar.
 

mmaattppoo

Adventurer
What a great idea. I love DIY mods and this is a great example of one. Also love the bedliner and that has been sitting on my bucket list since i tore out my JKUs carpets two years ago. Great work.
Thanks! The application of bedliner is definitely a great mod. I've been working up the courage to apply bedliner to the interior/floor. Perhaps next summer I'll apply some to the floor of the rear cargo area. I've still got three 1L bottles of Raptor Liner to use up. The liner I've applied thus far only used 1 bottle.
 

mmaattppoo

Adventurer
Is this the one you used? How is it held in place: screws or rivets?

https://www.millsupply.com/hingeless-steel-2-way-vent-m1217.php?p=51618
I used this one: https://www.millsupply.com/hingeless-aluminum-2-way-vent-t23170al.php?p=51612&cs=1+547+550

It's aluminum instead of steel but the form is essentially the same. I sanded the bare aluminum and applied Rustoleum Bedliner spray (rattle can) to make it black and to prevent corrosion of the aluminum.

I orginally planned to use stainless steel nuts / bolts but due to the curvature of the hood ended up using 3M VHB (very high bond) acrylic foam tape...very strong bond and takes up some of the irregularities in the mounting surface. Also, using fasteners would have necessitated placing the mounting flange on the outside of the hood to avoid dimpling the painted surface of the hood where the fasteners touch the hood. I filled in the small gap between the black plastic trim and the vent body with black RTV silicone. Makes for a clean finish and seals the attachment point to prevent water entering and dripping into the engine bay.

3M VHB tape is a little pricy but we'll worth it. If you haven't heard of it or used it have a look on YouTube for videos of its use. I've used this product in several instances where it just wasn't practical to use rivets or nuts/bolts.



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mmaattppoo

Adventurer
I just couldn't leave well enough alone and installed a 5.2" Spal paddle blade pusher fan to force approximately 300 CFM through the pop-up vent no matter what speed I'm travelling at. This little fan is not subtle about the movement of air as you definitely know when it has been switched on by the satisfying sound it makes.

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This installation entailed fabricating an enclosure from 26 ga galvinized sheet steel that completely seals the underside of the pop-up vent and provides a base to mount the fan.

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The two sides and flanged mounting surfaces were all fastened with 3M VHB tape. So far after a week of driving around all of the seams are holding strong with no signs of the pieces separating.

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Like the pop up vent I coated the finished enclosure with Rustoleum rattle can truck bed liner, attached the completed assembly to the underside of the hood using 3M VHB tape, and sealed the perimeter and all interior/exterior seams with black RTV silicone to form an air and water tight seal. The RTV silicone provides some adhesion between the enclosure and the underside of the hood but the majority of the "sticking force" between the enclosure and hood is provided by the VHB tape.

I will need to drill a couple of small drain holes in the enclosure to drain any water that may enter the vent.

Now I just need winter to be over so I can put this fan to work during the summer when it's needed.


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mmaattppoo

Adventurer
Picked up a FLIR One for my Samsung Note 5 and shot some long wave IR images of my Jeep's front end and the hood vent...very interesting. The maximum temperatures measured/approximated in these photos is about 50°C (122°F) and located inside the pop-up vent.

These images were taken immediately upon arriving home after an hour long commute from work in moderate traffic and 20°C (69°F) rain free conditions.

Brighter and whiter colours are hotter and darker blues and purples are cooler.

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MOguy

Explorer
I have an 01 TJ and have had heat soak issues in the past. The TJ and maybe the JK has a rubber seal that runs across the back of the hood. Pulling off that seal will allow heat to escape. No cutting needed.

I have never had overheating issues with the TJ and didn't notice any drop on the temperature gauge but I do have less issues with heat soak after doing that.
 

Mitch502

Explorer
I have an 01 TJ and have had heat soak issues in the past. The TJ and maybe the JK has a rubber seal that runs across the back of the hood. Pulling off that seal will allow heat to escape. No cutting needed.

I have never had overheating issues with the TJ and didn't notice any drop on the temperature gauge but I do have less issues with heat soak after doing that.


Zj's have the same thing. Only issue for me is water will drop into the rear pass cylinder and rust the spark plug and cause arcing. I think the I6 is clear back there, just check it to make sure if you haven't already!
 

mmaattppoo

Adventurer
Awesome! Where did you get the attachment for your phone?

Thermography is a wonderful thing. I purchased a second generation FLIR One online for ~375 Canadian pesos (~$290 USD)...there are better prices out there but availability of this device in Canada is limited so I took what I could get. The second generation of this attachment comes in both Android (USB - B) and iOS (Lightening Connector) versions and is readily available directly from FLIR and Amazon for ~$250 USD (http://www.amazon.com/FLIR-ONE-Thermal-Imager-Android/dp/B00W5PRY52). There are a few competing options (e.g. Seek Thermal and ThermApp) but the FLIR One met my needs.

I plan to shoot some more images under varying conditions and under the hood and will post more as I go.
 

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