A Buying Guide to Snorkels

The following buying guide contains a bit of info on most things that you might want to know before investing in a 4WD snorkel.

Note: At Outback Equipment, we only supply Tuff Terrain snorkels constructed from LLDPE plastic. The following information is purely for research purposes for our customers.

The addition of a snorkel can be a great investment in your 4WD as well as being one of the more inexpensive modifications you can make to prolong the life of your vehicle. This is mainly in relation to those who go off-road and do a lot of long-distance driving in general. Plus a snorkel can be a good-looking addition to your rig.

If you’re thinking about attaching a snorkel to your car, you want to ensure it is being done correctly (preferably by a professional) and for the right reasons. This is mainly because if you’re cutting a hole in your guard to make room for a snorkel, then this could quickly turn into a very inconvenient thing to fix if done incorrectly.

 

Why install a snorkel?

The function of a snorkel is to elevate the air intake, which serves two purposes:

  1. To mitigate the effect of dust and water on the engine
  2. Acquire the cooler and fresher air that passes over the vehicle

Reduce dust particles

Plumes of dust from off-roading or traveling on unsealed roads will be your air intake’s worst enemy. A snorkel will elevate your air intake, moving it further away from thick dust clouds and heavier dirt particles that get whipped up by your wheels or the wheels of anyone in front of you. Dust will still get into the snorkel’s head but it won’t be as thick. Different snorkel heads have different ways of expelling dust.

Any excess dust that gets through will get captured by your engine filters. The life of the filters will also last longer because they are not having to collect as much as they normally would without a snorkel. Extending air filter effectiveness means reducing the wear of vital components, which will help in prolonging the engine’s life and reliability.

Prevent water intake

By raising the level of the air intake, this will also reduce the likeliness of water entering the engine when fording water crossings. If you’re travelling through flooded areas or creeks without a snorkel, water is very likely to enter the air intake and filter making your engine seize and your vehicle come to a halt.

If water gets sucked into your engine then it could hydrolock. This is because water does not compress like air, thus jamming the cylinders and severely damaging the engine.

A snorkel by itself will not provide a complete water proof solution for your engine but it is a very good start. There are many points of entry for water to get into your engine and while there are many preventative measures you can take, nothing is an absolute guarantee.

Cooler air

The air intake of an engine is usually designed facing forward, as close to the grille as possible to counter the hot temperatures under the bonnet. Cool air is necessary as it contains more oxygen, which is essential to more efficient combustion, or how well fuel is burned for better vehicle performance. However, whilst this location may be cooler compared to the rest of the engine bay, the air is still warmer and laden with dust particles at this level. By utilising a snorkel, cooler and cleaner air is drawn from the windscreen/roof level to benefit your engine.

 

Snorkel Materials:

LLDPE Plastic Snorkel:

Commercially available snorkels are generally made from UV resistant Linear Low Density Polyethylene (LLDPE) — . LLDPE is a strong and durable plastic that is usually impact resistant depending on the thickness of it. When used in snorkel manufacture, LLDPE is usually combined with a carbon black raw additive to give the snorkels a nice black finish as well as offering an extra layer of UV protection against cracking and fading.

After-market snorkels are also roto-moulded to suit individual vehicle models so they hug the body and offer maximum strength. Roto-moulded snorkels are also usually manufactured as one piece, avoiding the need for joins and sealers on the snorkel itself. Because of the unique shape of vehicle specific snorkels, they are usually flow-tested to ensure air flow is not restricted. This is to dispel the belief that air flow through an aftermarket plastic snorkel is inadequate when compared to the generous flow of a PVC or stainless steel pipe. However, some DIYers will choose polyethylene plastic pipes over PVC if attempting their own custom made snorkel.

 

PVC Snorkel:

PVC piping is usually utilised in DIY snorkel construction. These are usually done with a minimal budget in mind, however, because PVC is a cheap material it isn’t highly regarded for longevity. Not as resistant as LLDPE to UV exposure, some 4WD forums have indicated PVC’s susceptibility to becoming brittle after prolonged exposure to the sun. However, because there are varying grades of PVC, its durability may differ across the board. PVC can also become brittle at very cold temperatures compared to LLDPE’s higher resistance to the cold.

The joints are also something that need to be considered as a PVC snorkel will not be one piece. Consider the fact that there will be more opportunity for leaks to occur as a result of having joints. Some DIYers will use solid joints and seals, but these do have the tendency to break often and may constantly need to be repaired. Rubber joints are good for flexibility, but again, this has to be the correct type of rubber to avoid getting brittle in the sun too quickly.

The upside of PVC is because it is a cheap material, it is easy and cheap to repair; just be mindful of how often you might have to repair a PVC snorkel as costs might begin to add up. If using PVC, make sure that the inside of the piping is not corrugated as this can impede effective airflow and can also make it a noisy experience as air rushes through.

 

Stainless Steel Snorkel:

Stainless steel is another material that is common amongst snorkel DIYers and custom welders mainly because of its sleek good looks. Many people also like stainless steel because it is quite tough— it can get badly scuffed, which can diminish its sex appeal, but otherwise it is good at staying intact.

Depending on who does the job, the joints of a stainless steel snorkel can be rubber or TIG (Tungsten Inert Gas) welded, with many preferring the sturdiness of a TIG welded elbow.

A stainless steel snorkel will also produce more induction sound. As to whether this is considered a positive or a negative when weighing up materials is entirely up to the individual. While some have complained about this being an annoyance, others have enjoyed the audible “breathing” of their snorkel.

Although not often thought about, the placement of a stainless steel snorkel also needs to be considered depending on how shiny it is. If it is too shiny and angled a certain way, then sun reflection could prove to be a safety issue when driving.

 

Mild Steel Snorkel:

Mild steel is a good option for those who like the idea of having a custom-made steel snorkel but don’t want to pay the extra money for stainless steel. While mild steel is cheaper than stainless steel, it is of a very different quality. Mild steel is more malleable and ductile so it can be shaped to your needs. It does, however, have a lower tensile strength and is also prone to rusting.

To prevent rusting, a mild steel snorkel would need to be painted both inside and outside or undergo a hot-dip galvanisation. The look of mild steel will not be quite the same as stainless steel after rust-proofing it — most people opt to just powder-coat it in black to give it an attractive finish. In terms of joints, welding mild steel also poses fewer problems than trying to weld stainless steel

 

Some other factors to remember when considering what you want your snorkel to be made of:

  • The colour of your snorkel, or the material that it is made of, will not affect the temperature of your airflow, i.e. a black snorkel or stainless steel snorkel will not necessarily make the airflow hot.
  • All snorkels will create induction sound. Many people do not seem to realise this prior to getting a snorkel installed and end up disappointed with the excess noise created, others love it. Those who have had a snorkel professionally installed sometimes believe it’s the fault of the mechanic/panel beater, but that “sucking” sound is to be expected. Ensure the snorkel is correctly secured to prevent vibrations as this can create an undesirable noise too.

 

Snorkel Heads:

There are two main types of snorkel heads:

  • Air Ram Head
  • Vortex Head (Also referred to as a Cyclone Head)

They are both designed to separate dust particles and water from the air but in different ways.

Air Ram Head:

As the name suggests, air is rammed into the snorkel as the vehicle is moving. The scoop design of the head forces the heavier particles of dust and water against the internal walls (mainly the back) where they drop down and are expelled through the vents located around the top of snorkel body. The “filtered” air rushes into the snorkel body to the engine free from harmful dirt and moisture. Whatever dirt that manages to escape into the snorkel will be taken care of by the engine’s air filters.

There is a misconception that the ramming action causes more air to be forced into the engine to help increase performance. The ramming of the air is generally just to help remove rain/moisture and larger dust particles out the rear of the snorkel head. A naturally aspirated engine cannot suddenly accept more air than what it requires for fuel combustion. Generally a supercharger or turbocharger is required to force more air into a combustion chamber to increase efficiency and power output, as well as electronically programming it to do so.

This again, reiterates the fact that a snorkel is mainly for the benefit of elevating your air intake to acquire cooler and cleaner air. If there are any improvements in fuel efficiency after installation then that is just a bonus.

Some people believe that the direction that a snorkel head faces can affect the performance of a vehicle. In harsh conditions such as heavy dust, snowfall, driving through mud, or low hanging fauna, drivers will turn their snorkel heads to face the rear to:

  • Reduce dust build-up in the filters
  • Avoid the snorkel clogging
  • Prevent the head being knocked off by branches

Reversing the snorkel head is perhaps ideal for vehicles that are travelling at lower speeds because of the apparent vacuum effect that occurs when in that position. There lies the perception that the engine is having to work harder to suck air in, as opposed to the natural flow of air being rammed into a snorkel when forward-facing. The results are generally inconclusive with an even spread of those having attempted to test the difference reporting variations from reduced power, no difference, or even better performance.

Some snorkel heads are designed so they cannot be turned around, for example, custom-made jobs and vehicle-branded genuine accessories. Custom-made jobs that use stainless steel or PVC sometimes won’t even have snorkel heads and are designed to have the snorkel intake permanently rear-facing. In saying all of this, it probably doesn’t matter which direction you want to keep your snorkel head. Because of the shape, a ram head was most likely engineered to sit forward, but turning it around temporarily in harsh conditions, shouldn’t hurt. Alternatively, using a vortex head might be a better option for dramatically dusty environments.

 

Vortex Head/Cyclone Head/Pre-Filter:

A vortex head is designed to work through centrifugal force. Air is pushed up through angled blades that are located at the base of the head. The angle of blades encourages the air to move in an upward circular motion away from the centre. As the air rushes around, the heavy dirt and water get pushed out. The internal chamber where the centrifugal action occurs gets narrower at the top — this is where the particles separate as they collect in an outer chamber, or simply get expelled through slots, depending on the design of the head. When the swirling air reaches the top of the chamber it then gets pushed downwards into the centre, getting directed down into the snorkel.

Vortex heads are best for harsher conditions where dust is particularly thick and abundant, or for navigating through swarms of flying critters. They are considered a better option than reversing a ram head because they are more effective at capturing excess dust before it can get further down the snorkel. At higher speeds, some drivers claimed to have experienced a slight loss in power, but these will always be the preferred snorkel head for very dusty environments. Vortex heads might also produce slightly louder induction noise but usually this isn’t a big deal when taking note of the dust separating benefits they offer.

Mushroom Head/Bird Feeder:

Essentially designed to operate the same way as a vortex head but instead of collecting dust to be disposed of later, it contains slits so water and dust can easily escape. They are also more enclosed than a ram head catering to those particularly worried about water from rain or car washing getting into their air intake. Rain is not normally an issue for snorkels but for some it can be a genuine concern and this design could very well dispel fears of water getting into the air intake.

 

Petrol or diesel?

Regardless of the engine you have, a snorkel will always serve a purpose and be beneficial for the air intake filters. Some people believe that snorkels are more useful for diesel engines as they pose a greater risk than petrol engines if their air filters become too dirty. This is because the combustion chamber requires a smooth and clean air stream. If there is not enough air to mix with the fuel then a richer mixture of diesel will spark. This creates a much hotter burn in the combustion chamber, which is not ideal for any engine and wastes fuel.

Another line of thought is the fact that diesel engines operate through compression ignition compared to petrol engines which use spark ignition. The compression ignition uses a greater air to fuel ratio because a much higher pressure is needed for the fuel mixture to burn — therefore more air is required to be compressed. Because of this, some people feel that having an air ram snorkel is ideal for pushing more air into the engine to help feed the compression, which as we mentioned under Air Ram Heads, isn't how a snorkel necessarily works.

Furthermore, the greater emphasis placed on the need for a snorkel for diesel engines might be because of their increased susceptibility to hydrolock. This is because of their smaller combustion chamber compared to petrol. As a result, the same amount of water that might get into a petrol engine and do little damage or no damage, could potentially have a disastrous outcome in a diesel. As previously stated, lifting the air intake with a snorkel will reduce the risk of water entering the engine.

Whilst all of these are mostly valid points as to why a diesel engine should have a snorkel, this does not discount a petrol engine’s need for a snorkel. Any 4WD that does a lot of driving through dusty terrain or through water requires a snorkel to prolong the life of the air intake and, in turn, protect the engine. Basically, a snorkel is a necessary addition to any 4x4 that is intended for touring and off-roading.

 

How much should I spend on a snorkel?

Ask a varied group of 4WD enthusiasts and you will get a mixed response as to which are the best snorkel brands on the market. While many four wheel drivers seem set in the belief that you get what you pay for, just as many are confident in the inexpensive aftermarket options with tried and tested results.

The price of buying and installing a snorkel will range from $100 to $700 depending on whether you go with a DIY job, or go with a lesser-known brand and self-installation, or go the whole kit and caboodle and go with an expensive brand and get professional installation.

An expensive snorkel does not necessarily equate to a better snorkel with countless forums equally praising and criticising both established and lesser-known brands.

The general consensus is, however, that a snorkel is probably only as good as its installation. This is where a professional with a vast amount of experience in installing snorkels is also a good investment. Ensuring all the vital components are tightened and sealed correctly will prevent vibrations, and keep unwanted foreign materials from getting under your hood, or worse, into your engine.

A professionally installed snorkel is more likely to be better fitted and thoroughly sealed to effectively deal with water crossings. In saying that, many people feel that installing a genuine vehicle branded snorkel from your dealer’s accessories department is probably not the best option as these are usually not sealed to the vehicle as well as they could be, making them ineffective in water crossings. These are more just for airflow and looks.

 

In Summary

Whether you’re going for looks or functionality, a snorkel will always be a nice little modification to your 4WD. For a snorkel to be a practical accessory, first consider the conditions you would be using your rig in after making the addition. If you’re only going to be driving within the confines of the city and the suburbs, then it really isn’t necessary (unless of course you just want it for looks).

However, a snorkel is an absolutely essential addition for off-roading, rural driving, and shallow water-crossings. Most importantly, once you’ve done all of your necessary research and made your decisions, make sure you get a trusted and experienced professional to install your snorkel. In no time you will be enjoying the ability to get off the beaten track while maintaining the longevity of your engine.

 

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