My version of a cowl snorkle

[dukie564]

so how deep would it be ok to drive in with this?

Assuming you sealed the airbox up well, and extended the vents for your differentials and distributor to that level...almost to the top of the wiper cowl. It's not really a submersion mod - it's more for quick dips in deep puddles/water crossings. The front of the jeep will always bob underwater or get a tidal wave of water over it if the water is deep enough. This mod saves your engine from hydrolocking in these cases.

 

[XJjomps]

how do you extend vent for the distributor

 

[dukie564]

there's a "nipple" vent on top of the dist cap. I used a 2 foot length of 5/16" transmission line over the nipple and ran it up to the top of the firewall, with the opening pointed down.

Edit: Here, you can see it in this photo

 

[Bdiddy11]

So...if my reading skills are good, this is essentially the same thing as adding a snorkel? Just not with a big tube running up the pillar?

Any other advantages to this system besides being able to cross not so deep water crossings.

 

[lazyxj]

Any other advantages to this system besides being able to cross not so deep water crossings.

It doubles as a cold air intake. It is a little louder at full throttle and not noticeable at cruise. It 2-1/2 years of use, as a DD, I see no downside.
http://www.flickr.com/photos/lwade/sets/72157622703531169/

 

[Bdiddy11]

So all you really gotta do is make a whole in the air box and make a whole in the firewall area, add some tubing and make sure it's neat and tidy?

Is there anything special that needs to be done where it connects to the firewall? And any downsides for when temps are super cold or super hot?

 

[dukie564]

Well yea, but you also have to block the front intake port on the airbox. The hole in the firewall I cut exactly 3" and the stock intake tube seals perfectly just stuck in there - nice and tight.

And no - no downsides. If it's hot outside it's still cooler than the engine bay, and if it's cold even better - engines run best using cold air

 

[Voteban]

I'm considering this mod because of this:

I was throwing up huge walls of muddy-watery-crap on everything, including showering my hood when I tried turning side to side to get unstuck (didn't work). The stock location of my airbox allowed a bunch of water and mud in there, ruining my filter. I also blew my radiator, thankfully before any crap got into my engine, and I ruined my alternator.

But, my cowl also got a ton of crap in it, so I don't know if this mod would have helped.. To this day, inside my cowl still has a ton of caked on dirt crap in it because of this mud hole.

Advice? :gag:

Edit: Don't say to stay out of the mud, because I already learned that lesson... I just don't to ruin my motor if I HAVE to go through deep water or mud.

 

[Bdiddy11]

I was thinking about this mod... and had this question.

Would there be any benefit of adding a little mini scoop towards the back of the mesh grill (on top facing away from the windshield) where the intake meets the firewall? Thus forcing more air into the piping into the airbox.

 

[dukie564]

none whatsoever. It sucks air from the cowl area, which is huge. Trying to force more air in is a worthless effort.

 

[dieselenthusiast]

Besides trying to block water when submerged, why would you block off the front of your OE air box? I think this mod would be most benefical when you are bringing in air from both places (cowl and OE intake).

 

[hubs97xj]

What would be the point of that?

 

[Skipper51]

Too much hot air would come in from the radiator and the fact that you don't need that much air in the box. Cold air is drawn from the cowl making this a true CAI.

 

[dieselenthusiast]

What would be the point of that?

More air

 

[dieselenthusiast]

Too much hot air would come in from the radiator and the fact that you don't need that much air in the box. Cold air is drawn from the cowl making this a true CAI.

You have a good argument, although it would be nice to see some data that shows bringing in air from the cowl is superior over the stock air intake. I think we make too many assumptions based on theoretical ideas rather than proven ideas.

 

[Skipper51]

Re: My version of a cowl snorkel

You have a good argument, although it would be nice to see some data that shows bringing in air from the cowl is superior over the stock air intake. I think we make too many assumptions based on theoretical ideas rather than proven ideas.

Good point, I have no data. :dunno:

My thought is that the air from outside through the cowl is cooler the the air behind the radiator but I have never done and experiment to prove it. :dunce:

I thought I saw where someone did have a temperature gun and took readings when the the air box was stock and with the air coming from the cowl at the air box and it was cooler with the air from the cowl but I don't remember where I saw it. If I find it again I will repost it here for everyone.
(EDIT) Now that I think about it he put a remote thermometer sensor he got from Home Depot in the air box and the gauge in the cab to do his experiment and it was cooler with the cowl air.

 

[dukie564]

yea data or not, the air inside the engine compartment is always going to be hotter than airt pulled from the exterior of the vehicle.

And the 3" pipe is more than sufficient to provide the required air to the engine without the front port being open. Think about the size of the tube that runs from the airbox to the throttle body, and the diameter of the throttle body itself. Those are the limiting factors to how much air you need/require

 

[?Blue?sdriver]

When I had Thumper I did the "Right hand side/cone filter IN the cowl" Mod, completely eliminating the stock air box, which I understand now was a bit wrong. but luckily at the time I was living in a very semi arid location, and I only really did it for the cold air. Did it work? YES. Completely so. I DID get it wet, and it did rain on it, with no negative effects, luckily. (No I dont have pics yes I know this post is worthless without them however) in my own case cowl temps were a full 20of lower, I was definitely getting more available volume, and as a result my already slightly hyper (Mid range power cam, aftermarket injectors, header, HF cat/muffler) Thumperxj was even quicker on the throttle and acceleration. I also netted 4 mpg, hand calculated, when I managed to behave and keep my foot out of it. My mod shared the same principle of this one except that the tube ran to the corner of the passenger side, and the cone filter sat IN the cowl. Thumper was killed on a highway, virtually rolled up into a ball when it was flipped while doing 100+. No I wasnt driving. A stupid now dead girl was. I have ?Blue? Now, and plan on doing this mod immediately, with testing to see how it stacks up against Thumpers old mod. On ?Blue? There is already a cone filter inside the stock airbox, and the airbox still retains its stock configuration. I expect to see at least slight gains in both air intake temperature(being lower) and mpg. ?Blue? is a completely stock 96 4.0 HO. Thumper was a slightly hopped up 93 4.0 HO. THANKS VERY MUCH FOR THIS THREAD, OP! Brilliant.:yelclap:

 

[dukie564]

sucks about your old rig. Glad i can provide some inspiration/ideas for the new one though. It's been working fantastic thus far.

 

[dieselenthusiast]

I drive a Dodge Cummins diesel, so I know the benefits of a cold air intake. That’s why I did a “forum search” to see what’s available. I have a 4” hole drilled into the bottom of my OE truck air box with a 4” duct scooping cold air from under the air dam. My fancy $99.00 aftermarket PSM cold air intake outperforms some of the most expensive $300.00 + aftermarket intakes. Since the air intake is forced air, there was no question that it would outperform other shielded types. The modification was also proven (tested) by outperforming the other air intakes.

Now with the Jeep Cherokee, the cowl intake setup is a little different. Instead of a ram air effect (similar to the OE setup), the cowl air intake requires a vacuum. Agreeing that the cowl provides more available cold air, I was questioning whether or not there was enough available air since it was having to suck instead of being forced.