Overland Tech: “To snorkel or not to snorkel,” that is the question

Snorkels in their natural habitat – the dusty Australian Outback
If you took a survey of people and asked them to rank which off-road accessory was most iconic for overland/expedition type vehicles, I would place a bet that the snorkel would be at the top of the list.  There’s just something about the raw aggressive looks of the bulky air intake jutting out from the side of the fender and following the windshield up to the roofline. Of all the various types and brands on the market the most recognizable would be the ARB Safari Snorkel.  Forged in the Australian Outback (the real one not the faux-Australian restaurant in the US), ARB snorkels appear on everything from Jeeps and Toyotas to Subarus and Holdens.  Down-under they seem to think they are essential.  What about the American overlander?  Do I need one?  Do you need one?  I think the answer we come up with might surprise you.

First, let’s deal with a major misconception about snorkels.  The question people ask when they see a snorkel is, “Do you really drive through water that deep?”  While snorkels do provide an added measure of fording ability, snorkels have more to do with dust than water.  Remember when I said ARB pretty much set the benchmark for the snorkel?  How much water do you see in the Australian Outback?  Go ahead, do a quick Google Maps search, I can wait.
Yeah, not a whole lot of water there.  The most ubiquitous thing in the Australian Outback are dirt roads. Long dusty washboarded dirt roads.  A conventional air intake on a 4×4 is located under the hood usually just behind the headlight.  This works fine in almost every on road and most off road scenarios.  The filter takes care of dust and debris while its high location mitigates the chances of water splashing up into the air intake during shallow water crossings of a reasonable depth. So if the factory air box is more than adequate, why add a snorkel?  Three reasons:
  • Dust.  As mentioned, the most beneficial thing about a snorkel is dust mitigation.  While the factory air box and filter do a good job of filtering out dust, if you do a lot of driving on dirt and gravel roads you will overwhelm the stock paper filter.  Most snorkel kits come with an upgraded, and sometimes oversized, filter and some even have an optional pre-filter as well.  This increase in surface area increases the capacity of the filter.  For the snorkel itself, the air intake is moved from under the hood to outside and then moved from a low position even with the headlights to a higher position even with the roofline.  If you’ve ever logged a lot of miles on a dry dusty road you can see the dust that collects on your rig is much heavier and thicker down low and as you go up your rig it gets less in volume and smaller in particle size.  The same goes for under your hood.  As you’re driving a dust cloud builds under your hood.  Your tires kick it up and your fan sucks it in.  This is more true when you’re not in the lead and you’re driving through someone else’s dust trail.  The higher altitude of the snorkel intake means it’s sucking less dust than the factory air box would be and with a larger filter you have more capacity to go further before replacing (or cleaning) the filter.  The very design of the snorkel also plays a roll.  Scoop snorkels force heavier particles like dust and rain to the back of the intake tube allowing the lighter air particles to navigate the maze of tubing into the filter element.  The round shape of mushroom cap style snorkels (think mil-spec snorkels on USMC HMMVEE’s) forces their air to whip around the cap forcing heavier particles out via centrifugal force.  With increased filter capacity it means going further off-road and maintaining peek operating efficiency.   As an overlander, this is essential since many of the trails we travel are unmaintained and we need our rigs at 100%.
Although popular, there is no need to turn the scoop around when it’s raining.

Although lacking the “ram-air” effect of a scoop snorkel, a vortex snorkel has it’s advantages.
  • Cold Air. A snorkel is basically a true “cold-air” intake.  Most OEM air boxes are located under the hood.  Even most aftermarket air intake kits leave the actual air box inlet under the hood in the OEM location.  On some 4x4s, especially Jeeps, under-hood temps can reach stifling levels.  That means the air being sucked in to the motor is hot thus making the motor unable to run at peak efficiency.  By moving the air intake source out from under the hood the air is fresher and cooler.  Even a hot 100 degree day outside is better than the 200+ degree temperatures under the hood.  This is even more true when moving slow.  Going down the highway at 70 mph there is a tunnel of air being rammed through the engine bay and sucked out under the chassis.  This keeps it cool, supplies the intake with fresh air, and keeps the radiator in check even without a high speed engine fan.  Slow down to an off-road pace of 10-20 or even 30 mph and you lose that ram-air effect.  This means a hotter radiator and exhaust heat-soaking the engine bay.  Coupled with road dust and you can see how this becomes a compounding issue.
  • Water.  Okay, yes, snorkels do help with water.  There, I said it.  Happy now? However, the snorkel itself isn’t enough.  As mentioned, the main functions for a snorkel are to mitigate dust and provide fresh cool air.  Most snorkel kits aren’t in-and-of-themselves water tight.  There are a lot of steps to go through to make your 4×4 capable of successfully fording deep water.  You’ll need to relocate breather tubes, seal up electronics, and tidy things up to prevent water from getting sucked in the other 100 holes in your engine.  However, even if you don’t plan on going swimming with your overlander, having a higher-than-stock intake will help mitigate water intake when splashing through the occasional stream crossing or mud hole.
So, all that said, do you need a snorkel? Not really.  Will it hurt to put one on? Certainly not.  Do I myself plan on running one on the LJ? Yup.  Here’s why. In addition to the above mentioned benefits, a snorkel is cheap insurance, or at least an added layer of defense, against destroying your motor and prolonging its lifespan.
ARB Safari Snorkel’s are proven tools of the Outback.
A while back I had a 1996 Jeep Grand Cherokee with the 5.2L Magnum V8.  I destroyed that motor getting stuck in a mud-hole that was just a little bit deeper than I had anticipated.  The motor never fully shut off (no hyrdo-lock), and I though I hadn’t gotten the intake deep enough to inhale water/mud, but I was wrong.  While driving home my oil pressure dropped from 40psi to 20psi and then from 20psi to zero.  By the time I made it into my driveway I had a bad case of piston slap and some wicked valve train noise.  A smarter man would have gotten it towed home, but this was during the time I was still a novice.  When I drained the oil it looked like a Wendy’s Frosty coming out.  Later, when I pulled the intake and heads off, it looked like Freddie Krueger had been loose in the cylinders trying to claw his way out.  There were tiny little rocks wedged between the pistons and the walls of the cylinder. The motor was toast.
Now, would a snorkel have prevented the motor damage? Not on it’s own.  It would have helped.  The intake box and factory paper filter were soaked.  Even the throttle body had evidence of mud on it.  Needless to say, a snorkel is on my shopping list.  It just isn’t at the top.

So, we’ve established a snorkel isn’t a bad idea. While you don’t “need” one, it’s not like you’ll get voted off the island for having one either.  If you’ve thought about it and you want to buy a snorkel, what else should you get?  You should get some longer hoses to reroute the breather tubes for the differentials.  Do the same with the crankcase vents.  While you’re at it waterproof the electronics as best you can.  However, all that is for a more detailed write up on mitigating water damage to your rig, so stay tuned to future posts.

Disclaimer: The author of this blog is in no way affiliated with ARB nor has he received any compensation for this post in the form of cash or product.  The ARB brand name and associated product name are trademarks of their respective holders and have been used, when appropriate, as an example due to their prominence in the off-road industry.  The goal of this piece is not to promote the ARB brand over any other, rather it is to educate the reader as to the ins-and-outs of whether or not they need an intake snorkel.