A cardinal rule to bear in mind when selecting motor oil is for our cherished consumers to always follow the manufacturers’ recommended specification for oil viscosity found in the vehicle/equipment owner’s manual. Nowadays modern engines have tighter tolerances and more sensitive emission systems. If the wrong oil is filled in the crankcase, it will change the three to five minutes it takes to bring the combustion chamber up to temperature. This will also alter how the variable valve timing works and can have implications for the catalytic converter. Hence, using a different viscosity oil (thinner or thicker) may cause your engine to stall, you may experience oil pressure and oil supply problems, especially in late-model engines with cylinder deactivation and/or variable valve timing (VVT). However, adding GG Friction Antidote to the manufacturers’ recommended specification for oil viscosity will certainly not alter your oil viscosity nor void your warranty. If you have your oil change done by a third party vendor, please ensure to have the third party vendor put pen to paper the OEM specified oil and GG Friction Antidote applied to your oil on the invoice/receipt when you service your lubricants, that way you are covered if there is a warranty issue with your vehicle/equipment.

The running cost element in your industry will definitely reduce to significant proportions when you incorporate GG Friction Antidote in your base lubricants and fuel regimen regardless of the oil, grease and fuel brand in use.

Even with your favorite fuel, oil or grease, you will experience enhanced performance and protection of your vehicle/equipment beyond the standard Original Equipment Manufacturer specifications ONLY by adding GG Friction Antidote.  Improved fuel economy and increased horsepower, cleaner & longer parts life (engine, transmission, gears, hubs, and fuel injectors), less wear, reduced noise and vibration, and longer mineral oil change intervals, reduced emissions, less blow-by and black smoke, significantly reduced downtime, maintenance and running cost.

Automotive

At GG we do not just sell GG Friction Antidote but provide product support and solutions in the automotive, oil, gas and allied industries. Our expert partners in the industrial laboratory sector provide readily available, customer-focused innovative tribology solutions that go above specific industry regulations and make a definite difference in the lives of our clients.  Our expert partners help you operate in more efficient and sustainable methods by optimizing and streamlining processes, improving efficiency, quality and productivity, reducing risk, verifying compliance and increasing speed to complete all output.

Our core service, solutions and support cover all industry sectors and touch the services that consumers around the world rely on every day.  Your equipment is valuable to GG and we welcome the opportunity to partner you in finding better ways to efficiently run, reduce your fleet maintenance costs and extend the lifecycle of your vehicle/equipment.  We understand how important uptime is to you, hence, part of supplying you with GG Friction Antidote is to provide you with excellent service, identifying your savings prospects, improving the performance and efficiency of your fleet, extending the duration for replacing your fleet, cost-effective operation of your fleet and high level of customer care.  At GG our work is dedicated to the success of our clients.

We help every player in the automotive industry improve performance, reduce cost and risk.  Our service focus on optimization your equipment with GG Friction Antidote, hence you will benefit from extended OEM equipment life maximum efficiency, increased uptime, extended maintenance intervals, lower operational cost and improved performance of your vehicle/equipment.  Our clients rely on our independent, accurate and cost-optimized maintenance solutions to enable them remain competitive in the face of stricter environmental regulations and increasing pressure in running cost.

Around and Around – Where the Oil Goes in Your Engine

Most people know to add oil to the top of their engines, and that oil drains out the bottom. Because we have worked in auto repair for decades, it is no mystery to us what happens between filling and changing the oil. However, it is surprising how huge the number of people who do not have a true picture of the path the oil travels while it makes its way around inside of the engine.

After several maintenance seminars, informal question and answer periods turn to the most-often asked question: “How often should I change my car’s oil, and what should I use?”

Figure 1

To answer that question, we would use the Socratic Method and ask a few questions of our own: What kind of car do you drive? What driving conditions do you encounter most? Where do you live? How old is your car?

The answer to these questions will determine the best oil for your vehicle, and how well it protects and lubricates your engine while it goes around and around inside. Where does the oil travel, in what order, and what exactly does it do inside your engine?

First, the oil you pour in the top of the engine goes through many paths eventually arriving in the bottom oil pan, often called the sump, where the drain plug is located. The oil goes through several different paths returning to the bottom – but only one path, under pressure, to do its job.

Figure 1 shows a tube with a loose-weave metal screen at the bottom of the pan. The screen is attached to a pickup tube, which leads directly to the oil pump. The tube and screen are submerged in the oil at a depth of about four inches. The screen prevents large pieces of trash, usually larger than 1/32nd of an inch, from entering the oil pump. Many people do not realize that most oil pumps are just a set of special gears, which take in the oil under low pressure and squeeze the oil to a high pressure, where it then passes through a chamber with a spring-loaded valve. The valve allows the oil to leave only under a specified pressure, usually between 1 and 60 lbs./in.² Any pressure higher than this will be vented back to the sump because high oil pressure can damage bearings.

From the pump, it goes to the outside of the oil filter, and there it is forced through the filter media to the center, where it exits into the oil galleries inside the engine. The oil filter also has a bypass valve to keep the pressure from dropping too low if the filter becomes clogged. The first and most important job of motor oil is to lubricate the rotating components of an engine, and it must be under good pressure to do its job.

Oil is forced into the space between the bearings making contact with the crankshaft journals and the journals. The bearings are simple metal sleeves encircling the rotating components of the engine. The block has main bearings on the crankshaft, and connecting rods bearings are on the crank throws. This thin space, usually one-thousandth of an inch on newer engines, holds a thin film of oil between the bearings and the moving surfaces on the crankshaft. Under pressure and within the correct operating temperature, the oil protects and prolongs the life of the machined parts. Metal should never touch other metallic surfaces while it is moving.

It is important to note that some of the oil is forced out of the sides of the bearings and drips back into the sump. If the clearance is too much, say 0.004 of an inch or better, pressure starts falling in the upper end of the engine. A flickering oil light or a slight tapping sound in the rocker arm area on the topside of the motor is a good indication that not enough oil under pressure is reaching the top end of the engine.

Looking aside for a minute, we would like to see an automotive engine with roller or needle bearings replace the far cheaper and sufficiently long-lived sleeve bearings. We know it would cost a fortune to build such a motor, but it would last forever. Many larger engines have needle/roller bearings. Generally they turn at lower rpm (speed) than gasoline car motors. RPM is not the limiting factor. We have flown model airplanes for decades and many of our highest-revving engines (25,000+ rpm compared to 2,500 rpm in an automobile engine) are equipped with roller bearings for lower friction and higher rpm. A roller/needle bearing-equipped auto engine would have higher power and longer life, but at what production cost?

Most of the oil lubricates the crankshaft area, while the remainder lubricates the camshaft and rocker arms. If your car has push rods rather than an overhead camshaft, then oil is forced under pressure into the valve lifters. These lifters also pump oil up through the hollow push rods to lubricate the rocker arm area. If your car has an overhead cam, the oil is carried to the cam and is spilled onto the contact points between the cam and valve stems.

After lubricating the camshaft and the related components, the oil flows by gravity back down channels in the head and motor block to the sump, ready to begin another journey.

In many of the connecting rod designs, there is a small hole that sprays oil onto the cylinder to lubricate the piston ring contact area of that cylinder. Special rings on the bottom of the piston ring set wipe off excess oil and return it to the sump.

Oil Consumption

Regarding oil consumption, it may likely be necessary for you to add a quart of oil to your engine, at regular 3,000-mile intervals. Most of the newer cars will not consume any oil the first few oil changes. Afterward, oil consumption will gradually increase with age. What is too much consumption? If I had to pick an ideal figure, I would say one quart every 5,000 miles. The best car we ever owned let us know it was time for a change by being a quart low regularly at 4,000 miles. We saved adding a quart and changed the whole sump of oil and the filter.

Why do we prefer a little oil consumption? In our opinion, those engines that consumed a little oil by allowing it to pass around the rings, kept wear on the upper cylinder and rings to a minimum. Decades ago, we used to add makeup oil to our gasoline for that same purpose.

External oil leaks can be messy, a potential fire hazard, and just plain ugly. Why do used car dealers go to great effort to clean a motor before exhibiting it for sale? Our general impression of the engine is formed around how clean it is and how smooth it runs. Most people open the hood before starting it up. If the salesman starts it up before he opens the hood, he is depending on the first impression of a well-running motor negating what will likely be a dirty motor under the hood. If the dealer has failed to clean the motor, it most likely has a bad oil leak he doesn’t want to fix. If he opens the hood and it runs well, look where the car is parked as you test drive it. Oil on the lot will give you a bargaining tool. Many types of leaks can be fixed for less than $100.

A reader wrote asking three distinct questions about his vehicle and its recently changed oil consumption. For 30,000 miles, his car had not used any oil between changes and suddenly it consumed oil at the rate of one quart per 1,000 miles. While the consumption rate is excessive, and we think there is some leakage or oil being burned, he did ask the following valid questions:

1. What is normal consumption? And why did his car not burn any oil for 30,000 miles?
2. Why does the oil consumption occur during highway miles and not during stop-and-go driving?
3. What caused the oil usage pattern to change after having driven the car this long (30,000 miles)?

Cars consume more and more oil with age. Normal consumption is a subjective call; we made ours at one quart per 5,000 miles. We also stated that many cars will not burn oil at all for a while – once again, a variable.

The fact that his consumption is brought on by highway conditions leads us to suspect an internal oil leak around the valve stems seals or some failure in the PCV system.

Until 1965, most cars and small trucks had a vent, often called a road draft tube, which vented the crankcase to the atmosphere. After 1965, legislation brought forward a governmentally mandated device to be installed on all vehicles. The positive crankcase ventilation (PCV) valve is a simple system that introduces filtered fresh air into the crankcase. The PCV valve uses the engine’s vacuum to pull air through the crankcase and reintroduce it back into the intake manifold system. This sends the uncombusted hydrocarbons and nitrous oxides that blew by the rings another chance for complete combustion, and in later vehicles, to be managed by the engine’s emission control system.

This system works great and is practically maintenance-free. However, a lack of knowledge coupled with the fact that the average driver does not open his engine bonnet at every fill-up, can lead to large problems. And, not knowing how and why the oil breathes can lead to expensive repair bills for your vehicle.

The consequences of ignorance about PCV systems can also be costly. The system is simple. As professionals, almost every week we see a malfunctioning PCV system literally grinding an engine to bits. The rubber hoses and grommets that are part of the system can swell and loosen their connection to the other parts of the engine. The results depend upon where the integrity of the connection fails. If the connection is loose and sucking air into the line between the air filter housing and the valve covers or other intake point, raw unfiltered air is introduced to the crankcase. This can grind bearings, overload the oil filter capacity and in general, make a junk pile of the engine. Many of the prematurely worn out engines we have seen can trace their failures to a long-term malfunction of the PCV system.

If the connection fails on the other side between the PCV and the intake manifold, raw blow-by products spew into the atmosphere. The results are the terribly messy, oil and dust-coated engine compartments that many of us have seen, and the release into the atmosphere of many aggressive pollutants.

Don’t let the ignorance, attention to detail, lack of knowledge and disregard for the simple PCV on your car cost you many miles of service from your modern-day combustion engine. Either you or your mechanic can inspect this entire system in just a few minutes. Hose, grommet or PCV replacements often cost less than $20. Do yourself and the environment a favor – check and/or repair this vital system this week.

Inspect Your PCV System
Try this for yourself: Check under the hood for a white plastic sticker, approximately 6 by 3 inches. Listed on it are the engine size, emission systems in use, spark plug gap, timing information and other useful information. Part of the sticker looks like a road map with colored lines. Look for PCV, ignoring the strange acronyms, such as EGR, MAP or VSERV. If you can locate the PCV valve on the engine, follow the map and check all hoses and connections for swelling or cracking. Replace any parts found loose, cracked, swollen or coated with motor oil. In general, if there is no evidence of oil leakage, there should be no problem. Malfunctioning PCV valves can be the source of a leak and can cause leaks in other gaskets on your engine. If in doubt, see a professional.

The fact that the pattern changed abruptly would reinforce our belief that a failure (either an undetected leak or abnormal consumption) is the culprit.

We have certain cars with more than 175,000 miles and they consume oil at the rate we like: one quart every 4,000 miles. Other newer car of ours with approximately 70,000 miles also consumes one quart per 4,000 miles, and has always done that.

Oil leaks are difficult to detect in a car. The engines are tightly enclosed and difficult to see from any angle. Add a list of accessories bolted to the block and visibility approaches impossibility. However, you can use some of the latest leak-finding techniques. Phosphorescence, polymer acrylic, ultraviolet, smoke, and maybe even mirrors.

GG Friction Antidote – An investment that pays off, your benefits at a glance:

Switching over to a high-performance lubricant pays off although purchasing costs may seem higher at first, less maintenance and longer vehicles/machinery parts lifecycle may already mean less strain on your budget in the short to medium term.

Dangers of Electrostatic Discharge in Engine Oil

Cold engine startups at very low temperatures have been a problem for consumers, manufacturers of power systems and the petroleum industry. With a cold start, the flow of circulating oil (a dielectric liquid) in the system can induce voltage spikes in portions of the circulation manifold during the initial warm-up period. When exposed to this spike, sensitive components such as sensors and microprocessors may break down and ultimately shut down the engine if the component is critical to operation.

When a power system is cold, its circulating oil has a very high viscosity and very low electrical conductivity. The oil will warm as the engine heats up, but for a period after a cold start, there will be the danger of static electric buildup in the oil and of potentially damaging spontaneous discharge.

Flow electrification of liquids has been a source of numerous industrial hazards, primarily in the petroleum and power industries. This effect occurs in improperly grounded systems carrying fuels, lubricating oils and other hydrocarbon liquids. This is why some commercial gasoline fuel hoses in the United States have an attached ground wire to dissipate electric charge accumulation during fueling operations and why regulations exist to shut off the engine when pumping fuel into a vehicle.

Static electrification of a dielectric liquid is due to the presence of trace elements in the oil. Examples of substances that can carry electric charge in a non-conducting liquid include various oxidized oil components, contaminating agents, metal salts and other ionized additives. The concentration of any of these substances at which liquid electrification occurs can be as low as 1 part per billion. Because of this low concentration, it is impractical to remove these trace elements. If you could remove them successfully, subsequent handling could reintroduce the elements through recontamination.

Engine oils in power systems are electrically insulating liquids with electrical conductivities in the range of less than 1,000 picosiemens (pS) in normal ambient conditions. The value will depend on how pure the oil is and whether it has been altered with additive surfactants. For most liquids, the product of their viscosity and electrical conductivity is constant. As the temperature goes down, the oil’s viscosity increases exponentially, and its electrical conductivity decreases exponentially.

During the startup phase, the system normally has a warm-up period due to viscous heating and heat transfer from other engine sources. The oil temperature rises, decreasing its viscosity and increasing its electrical conductivity until a steady-state operating condition is reached. The variation of electrical conductivity with temperature is the principal cause of the electrostatic discharge during a cold start.

This graphic illustrates the unsteady electrification
of circulating oil during a cold startup. Oil temperature
is depicted by the yellow/orange bar,
which darkens as temperature increases. The
electrical charge concentration is shown in blue
for the lowest concentration to purple for the densest.

The ability of a liquid to retain its electrical charge will depend on its electrical conductivity. In dielectric liquids, the time that an isolated liquid mass can remain electrified is known as its electrical relaxation time. It is inversely proportional to its electrical conductivity. For different commercial oils, this time constant is in the range of 1 microsecond to 1,000 seconds for higher to lower conductivities. For any lubricating oil at very low temperatures during a cold start, the relaxation time of the liquid is closer to the upper limit, whereas under steady-state operation, it has values closer to the lower limit. Accordingly, during a cold start, the electrified oil will remain charged, and if moved, can give rise to charge accumulation in the circulating system.

Once electrified, the distance that the oil can carry the charges depends on its electrical relaxation time as well as the bulk velocity of the flowing oil. In the warm-up phase of a power system, both the velocity and electrical conductivity of the circulating oil increase with time. At the start, the velocity and conductivity of the oil are low, and thus the electrification is limited to regions close to the charge source without electric charge buildup or any potential damage.

On the other hand, with normal operations, any static electrification in the moving oil will travel very short distances. The oil will become neutralized, and the electrical charges will dissipate to the adjacent walls.

However, as the engine warms up from a cold start, there can be a time interval in which the oil velocity is high enough and the conductivity is still low enough so that moving oil will give rise to charge accumulation with the potential to do damage.

This chart shows the voltage output from a charge density probe over time. The solid line represents experimental measurements, while the dashed line is the theoretical prediction.

Yet another temperature effect involves the induced charge concentration behind a charge source such as a filter. In most cases, filter electric charging depends on a number of parameters related to filter geometry and flow conditions. For industrial filters used in power systems, the charging behind the filter is saturated and will be proportional to the liquid electrical conductivity. So as the temperature rises during a cold start, the filter charging will also increase with time during the warm-up period.

Accordingly, as the temperature rises with time downstream of a charge source, there is a significant increase in the induced electrification of the liquid and a decrease in the effective length of the electrified oil. The combination of these two counter-effects will be a transient charging effect in the form of a voltage spike and an electrostatic charge surge downstream of the charge source where the oil flows.

How low must the starting temperature be for this hazard to pose a practical problem? In general, the severity of this transient effect is influenced by a wide range of variables, such as the size and arrangements of the compartments in the circulation system, the base electrical conductivity of the circulating oil, the types of filters and pumps used in the system, the flow-volume rate, and the system’s temperature profiles during the warm-up phase and at startup. Therefore, a complete system analysis is needed to answer the question.

In one particular system that was recently analyzed, the starting temperature in the experimental setup was minus 41 degrees C, with the maximum voltage of 500 volts estimated at about minus 10 degrees C. For this system, any starting temperature below minus 10 degrees C could induce a severe spike. However, during experiments at higher temperatures, a similar but milder response was observed.

Preheating the engine block is unlikely to mitigate the hazard of a voltage spike. While preheating might help the engine start, it may potentially amplify the voltage spike. Engine oil is often stored in an oil pan that is not in contact with the main engine block. So if the engine components are warm and the circulating oil is very cold, oil electrification will be enhanced.

A system that can warm the engine oil and not the engine block would seem to offer a solution, and several such systems currently exist for specific engines. However, this solution is not practical for all power systems because oil in the pan may not be easily accessible.

Another solution is to use a bypass system for certain components such as filters that can be triggered by a differential pressure across the component. While this is a promising technology and filter manufacturers have begun to utilize this bypass system, there are still a few drawbacks. One is that the system is now more complex and more susceptible to failure. The other is that if new oil is used, the settings for the bypass condition should also be changed accordingly. Moreover, this technology can’t be used for other components such as an oil pump, which can also induce charging in the oil.

One might envision a change in the engine’s arrangement with the oil storage unit placed within the engine block. This is analogous to systems in some hybrid-engine cars that store hot coolant inside the engine for better start-stop performance. Still, the best option would be electrical grounding of the engine compartments during early stages of a cold startup to prevent charge accumulation.

While few if any studies have been conducted on these types of cold startup issues for automobiles, as advanced engines continue to include more electronics, this hazard could potentially pose a problem for them as well. This is both a practical and fundamental problem, and new research is needed to shed light on this phenomenon with respect to the temperature effects and other transitory behavior of the system.

Tip: The Value of Proactive Maintenance

Catching a problem before failure occurs results in repair costs that are 5 to 25 percent of most engines’ value. Catching a problem after failure occurs leads to repairs that are more than 65 percent of the engine’s value.

Anatomy of an Oil Filter

The oil filter will be examined to uncover its functional and performance characteristics. Several other related topics will also be discussed, including best practices for oil filter usage, possible filter failure modes, factors for proper filter selection and how to maintain an installed filter.

By definition, an oil filter’s main role is to cleanse oil from destructive contaminants within a machine such as an engine, transmission, hydraulic system and other oil-dependent systems. In the case of automotive oil filters, canister-type filters are the most common. This filter configuration was most likely responsible for the advanced performance of oil filtration technology.

In 1922, Ernest Sweetland invented the first oil filter device for automobiles. It was named the “Purolator,” which was short for “pure oil later.” The spin-on filters common in today’s automotive industry were introduced in the 1950s and were virtually a standard by the early 1970s.

Aside from the automotive industry, oil filtration is an integral part of equipment within a wide variety of industries, including aerospace, power generation, oil refining, manufacturing, mining, etc. Although most current oil filter designs come in canister or cartridge types, several variations in size, filter media, dirt-holding capacities and flow arrangements are available. For this reason, it is important that filters and filtration systems are selected to meet the needs of the application and with cost, performance, ease of use and environmental conditions in mind.

Oil Filter Types

Oil filters can be characterized by the method in which the contaminants are filtered or the method in which the oil flows through the housing. One technique used to control contamination in filters is through surface-type media. This is the type of filter used in automobiles. In depth-type filters, the filter media are designed to hold much higher levels of contamination and provide a more circuitous path for lubricant contaminants to become trapped.

Other possible contamination control methods include magnetic and centrifugal filtration. Magnetic filtration utilizes rare-earth magnets or electromagnets to attract and collect ferrous particles as the oil passes through a magnetic flux region. Centrifugal filtration works by integrating a rapidly rotating cylinder to produce a centrifugal force for contamination separation from the oil.

Oil filters can also be categorized by the oil flow design. As its name implies, a full-flow filter will draw all of the oil through the filter media. On the other hand, a bypass filter only requires a fraction of the oil flow for sufficient flow rates within the system. The application’s oil flow and contamination control requirements will determine which design is the best option. Another alternative is the duplex filter system, which contains two side-by-side filters in parallel to allow one of the filters to be replaced during uninterrupted operation.

With typical canister-type filters, it is standard for oil to flow from the outside in. This means that the oil travels through the cylindrical filter media from the outward-facing surface into the inner core. However, in some cases the flow direction is reversed, with the oil coming into the filter through the core and pushed outward through a unique pleat design. This is intended to improve flow handling and distribution as well as reduce filter element size.

Filtration Mechanisms and Filter Media

A filter’s primary function is to remove and retain contaminants as oil flows through the porous component called the media. The media operate under several types of filtration mechanisms, including:

• Direct Interception and Depth Entrapment – Particle blockage on the media due to the particles being larger than the taken passages within the media.
• Adsorption – The electrostatic or molecular attraction of particles between the particles and the media.
• Inertial Impaction – Particles are impacted onto the filter media by inertia and held there by adsorption as the oil flows around.
• Brownian Movement – This causes particles smaller than 1 micron to move irrespectively of the fluid flow and results in the particles being adsorbed by media in close proximity. It is much less prevalent, especially in viscous fluids.
• Gravitation Effects – These allow much larger particles to settle away from fluid flow regions when there is low flow.

In addition, filter media can be designed to capture particles through two distinct methods:

• Surface Retention – Contaminants are held at the surface of the media. This provides an opportunity for the contaminant to become trapped as it comes in contact with the media surface.
• Depth Retention – Contaminants are held either at the surface of the media or within the labyrinth of passages within the “depth” of the filter media. This creates several opportunities for contaminants to become trapped.

The graph below shows how depth-type filtration is more efficient in capturing smaller particles when compared to surface-type filters. This can be attributed to the deeper media providing more chances for the particles to be trapped along with the adsorptive and Brownian movement effects being more predominant in depth-type filters. While these characteristics are beneficial, depth-type filters tend to have higher differential pressure across the media as a result of the increased flow restriction from the deeper filter media.

Particle size retention characteristics of
depth-type and surface-type filter media.

Filter Media Types and Dirt-Holding Capacity

In the September-October 2012 issue of Machinery Lubrication, Wes Cash explained how the porosity of the filter media plays a role in how well the filter can retain captured particles. This is known as the dirt-holding capacity. As pore size goes down, to maintain a low differential pressure across the media, the pore density must go up to account for the oil volume in contact with the surface. The filter depth and size also influence the dirt-holding capacity. Another factor is the filter media material. There are three primary types of filter media:

1. Cellulose – Comprised of wood pulp with large fibers and an inconsistent pore size.
2. Fiberglass (Synthetic) – Comprised of smaller, man-made glass fibers with a more consistent pore size.
3. Composite – Comprised of a combination of cellulose and fiberglass material.

Cellulose media are advantageous because they can absorb some water contamination. However, these types of media tend to fail more rapidly than synthetic media in acidic and harsh oil conditions. Nevertheless, the primary reason synthetic filter media are preferred is their more consistent porosity and smaller fiber size, which contributes to higher dirt-holding capacity and longevity of the filter.

This example of a depth-type filter has an element that requires
oil to pass through 114 millimeters of filter media
for maximum particle filtration. (Courtesy Triple R)

Understanding the Beta Rating

Oil filters are rated by a technique called the beta rating. In his Machinery Lubrication article “Understanding Filter Efficiency and Beta Ratios,” Jeremy Wright explained the methodology behind the beta rating in more detail. In short, the beta ratio is calculated by dividing the number of particles larger than a certain size upstream of the filter by the number of particles of the same size downstream of the filter. Every filter will have multiple beta ratios for different particle size limits such as 2, 5 or 10 microns.

Best Practices for Oil Filter Usage

Storage – Filters can fail long before they are to be used for their intended purpose. Therefore, proper filter storage and handling are essential. Ensure filters are kept clean, cool and dry, and always follow the first-in/first-out rule.

Installation – Even if a filter installation seems simple and routine, refer to the manufacturer’s recommendations for proper procedures. A classic mistake is over-tightening. Most recommendations suggest that a three-quarter turn after seal contact is optimal. Over- or under-tightening can inhibit the seal’s longevity and effectiveness. Confirm that connections, seals and ducts are fitted appropriately and are free of contaminants.

Avoiding Pre-fill – In most cases, you do not want to pre-fill your oil filters before installation. In diesel engines, it is recommended that a pre-lube system be installed instead in order to counteract changes from dry-start conditions.

Choosing Correctly – Many filters and filter housings are designed to be interchangeable, so just because a particular filter fits doesn’t mean it is the correct filter. Make sure each filter is replaced with the right filter. This may not necessarily be the one found on the machine, as an incorrect filter might have been used during the last filter change.

Training – Proper training must be conducted for all personnel involved with changing filters. Remember, a task that seems straightforward to most people may not be for a new employee.

Filter Failure Modes

Channeling – During high differential pressures, filter media passages can enlarge to a point where unfiltered oil can pass through without an efficient contaminant capture. In addition, any particles that were previously contained within the filter in line with the enlarged passage may now be set free.

Fatigue Cracks – In cyclic flow conditions, cracks can form within the filter media, allowing a breach of oil to pass through unfiltered.

Media Migration – Media fibers can deteriorate and produce new contaminants made up of filter material. This may be caused by improper placement of the filter housing or an inadequate fitting of the filter, which can generate damaging vibrations. Embrittlement from incompatible oils or extremely high differential pressures can also result in media disintegration.

Plugging – During operation, filter media can become fully plugged by exceeding the dirt-holding capacity. Plugging can occur prematurely if excessive moisture, coolant or oxidative products like sludge are present. Majority of lubrication professionals say filter plugging is the failure mode seen most frequently in oil filters at their plant.

Factors for Proper Oil Filter Selection

Structural Integrity – Arguably the most critical factor, structural integrity relates to a filter’s ability to prevent the passage of oil through an unfiltered flow path. The International Organization for Standardization (ISO) has established procedures for testing fabrication integrity, material compatibility, end load and flow fatigue. These tests can reveal defects such as improper sealing of seams and end caps or breaks in the media from high-flow conditions, as well as the effects of high temperatures on the filter element.

Contamination (Dirt-Holding) Capacity – This refers to the amount of contaminants that can be loaded onto the filter before the filter’s efficiency is limited.

Pressure Loss – This involves the overall differential pressure lost from the filter’s placement on the system. The pressure loss will be influenced by the filter media’s porosity and surface area.

Particle Capture Efficiency – This is the overall effectiveness of the filtration mechanisms within the filter media to extract and retain contaminants from the oil.

System/Environment – The characteristics of the system and environment in which the filter will be installed must be considered, including the contamination expectations, flow rates, location, vibration, etc.

Maintaining Installed Filters

The best way to prevent filters from reaching their dirt-holding capacity is to avoid contaminants in the system from the beginning. The fewer external contaminants that ingress, the fewer contaminants that are generated internally (particles produce particles). Use the following guidelines to maintain installed filters:

• Ensure proper breathers are installed to prevent contaminants and moisture from entering the system.
• Keep seals and cylinders clean and dry by using appropriate wipers and boots.
• Select the appropriate oil grade and additive package to counter contaminant ingression and internal friction.

Analyzing the Filter

A filter not only is a trap for the machine’s undesirables but also a concentration of clues as to what’s occurring within the machine. Particles within the oil may be so highly diluted that practical analysis can become a daunting challenge. However, the particles trapped in the filter may be so plentiful that they can be easily visible to the naked eye.

Metal contaminants are a primary indication of an issue within the machine. Although some amount of metal contaminants can be expected, an unusual amount should be recognized by trending the filter’s visual appearance after each oil change. Cutting open the filter and suspending a strong magnet over it can aid in pulling out the metal contaminants to more easily distinguish them.

If the machine is suspected to have an issue, the filter should not be discarded, as this would be similar to throwing away key pieces of evidence. Maintain the filter in the same condition as when it was removed and have it analyzed by the manufacturer or a laboratory.

Filter Disposal

Oil filters are not designed to be dumped into any wastebasket. Increasing regulations by the Environmental Protection Agency dictate proper filter disposal. While each type of oil filter may have its own requirements, common practices include oil draining, crushing or incinerating the filter. Many disposal services or filter distribution centers will accept used oil filters at little or no cost.

Oil Filter Advice

Filters are an integral part of the oil cycle in an engine. If I were changing my mind about what lubricant to recommend, I should also reevaluate my oil filter recommendations.

Automotive oil filters fall into two categories, full-flow and bypass. Bypass oil filters take about 10 percent of the oil pumped from the sump, filter it and then return it to the sump while the remaining 90 percent is delivered to the lubricated components. Full-flow oil filters filter 100 percent of the oil pumped before it continues on to the lubricated surfaces. It might seem that the full-flow filter would be the best oil filter, though that is not necessarily true. Each has its virtues and vices.

No Oil Filter

Early car engines did not employ oil filters. The forerunner to oil filtration was mesh and screen strainers. I don’t consider screen or mesh to be an effective filter. There were cars manufactured through the late 1960s that did not have oil filters at all. (Anyone have a 1960s-model Volkswagen or Fiat?) The first VW I saw with an oil filter was the water-cooled VW Rabbit in 1975. The VW Super Beetle had a full-flow filter after 1972 until production stopped in 1980. There was also a full-flow filter on the 1975 VW sedan and the 1980 VW convertible.

Bypass Oil Filters

Bypass oil filters were the first oil filters on cars. They’ve been installed on cars and light trucks since the early 1920s. Ernest Sweetland introduced the first modern oil filter which promised “pure oil later” … so named because it was located between the pump and the sump, and it promised to deliver the pure oil later to the bearing surfaces.¹ The filter was a heavy metal case; inside was a series of metal plates with twill weave material around each plate. A sight glass let the user know when the oil flow dwindled to a trickle. At this point the whole filter unit, case, sight glass, plates and twill material had to be replaced. This was the beginning of the Purolator oil filter company.

Mr. Sweetland’s filter was improved by introducing replacement cotton fiber filtration in the late 1930s, which could be changed without replacing the whole filter unit. However, it remained a bypass oil filter, where 90 percent of the oil was sent to the engine unfiltered. As long as the oil contamination rates were low and the oil was changed frequently, the bearings had some reasonable life expectation. Most automotive oil filters were the bypass-type until the mid-1940s.

Forty-five years ago an engine could run 100,000 miles before needing an overhaul. All the engine required was care and persistent maintenance. In that age of $2,000-cars and oil costing $0.25 per quart, oil filtration methods and schedules were doing a fiscally responsible job. By 1950, most new cars were built with full-flow filters. The increased use of full-flow oil filters accompanied a decrease in bypass filter application.

Full-flow Filters

What was the reasoning for the shift to full-flow filters? It’s simple – all the oil, not the 10 percent of bypass norms, was filtered before it was sent to the oil gallery. Ideally, we would like to see particles somewhat smaller than five microns trapped by the oil filter, however, there are typically price and performance trade-offs with finer filtration.

Judging a filter only by its micron-size trapping ability has its limitations. My barbeque grill will filter five microns; a few five-micron particles will catch on the grill as fluid passes over. The SAE HS806 standard uses both a single-pass test and a multipass test, assessing dirt-holding, contaminant capacity in grams, and efficiency based on weight. The efficiency of the filter is determined by weight only through gravimetric measurement of the filtered test liquid. Typical numbers for cellulose paper filter elements are 85 percent (single-pass) and 80 percent (multipass).

The SAE J1858 test provides both particle counting and gravimetric measurement to measure dirt-holding capacity and capture efficiency. Actual counts of contaminant particles by size are obtained every 10 minutes, both upstream (before the filter) and downstream (after the filter), for evaluation. From this data, a filtration ratio and capture efficiency above different contaminant particle sizes can be determined as well as dirt-holding capacity and pressure drop as a function of time. Typical numbers for paper element filters are 40 percent capture efficiency at 10 microns, 60 percent at 20 microns, 93 percent at 30 microns, and 97 percent at 40 microns.

Oil filter design is somewhat of a balancing act between particulate size, filter medium, surface area of filter medium and oil pressure. The finer the filter medium, the shorter a filter’s lifespan before it begins to show pressure drop and the oil filter bypass valve is opened. However, new synthetic filter media and pleating configurations have managed to overcome some of these drawbacks. We have the capacity to filter out particles smaller than needed (less than two microns) to protect the oil between bearing surfaces, but determining the right balance can be a real puzzle.

The original full-flow filters were housed in heavy canisters. The element was changed, the canister was cleaned, and a new sealing ring was installed. In about 1955, however, the full-flow filter as we recognize it today was introduced. Within a few years, almost all cars featured the present-day disposable, spin-on filter with a lightweight canister and its own sealing ring.

Choosing a Filter – Full-flow or Bypass

Bypass filters are not new to the automotive environment. They were the first filters installed on cars, but have since been replaced by full-flow filters on almost 100 percent of the new cars manufactured today. I am, however going to vote for both types of filters; each stands out in certain conditions. Ford Motor recently announced that it is equipping its 2005 E Series with bypass filtration.

I am a big advocate of oil coolers to help ease the burden on the lubricant. Cars last longer with oil coolers. Cars last longer with better filtration and timely oil and filter changes. Cars last longer with cleaner oil. The trucking industry is ahead of the auto industry on recognizing the importance of cleaner oil. There is, in the trucking industry, a reasonable expectation of 500,000 miles between major overhauls. Why the long interval? Truck manufacturers use both bypass and full-flow filters, oil coolers and transmission coolers. In short, they use it all and have the results to justify their expenditure. One million miles between overhauls is no longer rare in the trucking industry.

With the replacement cost of my wife’s 1998 Buick Park Avenue approaching $35,000 I need to make that car last as long as I can. Any reasonably priced device that would extend its life beyond 200,000 miles (it is currently at 88,000 miles) is of interest, and is financially beneficial to me. Some of the advertisers in ML make or sell bypass filters for modern automobiles.

There are now oil filter units commercially available for passenger cars that employ both the bypass and full-flow filters. I’ve found a neat place under the hood of the Park Avenue to mount the manifold and filters. I think I will check the dimensions one last time and purchase one.

Final Note
Any dirt that gets past the air filter enters the engine, becoming the enemy of all lubricated components. This makes the oil filter’s job more challenging. To combat such wear, change your air filter regularly.

PCV System – A Breath of Fresh Air

Oil pollution has been in the news and on our minds a lot in the last 25 years. Disposing of waste oil from my father’s gas stations in the mid 1970s was easy to do. In Louisiana, many of the unpaved roads were covered with prehistoric clamshells dredged from the bottom of Lake Ponchartrain. During the dry summer months, traffic ground the shells to dust. Friends and neighbors would wait anxiously for us to give them waste oil from the gas station to spray on the shells in the streets in front of their homes to reduce the dust. Otherwise, everything would be covered with a fine white powder. (I like to tell this story to young EPA employees in my area just to watch them shudder.)

Modern road construction incorporates paving, the EPA has banned shell dredging, and good old crushed granite is now used for unpaved driveways. The dust problem is not as big today as it was back then.

Pollution of the crankcase oil increases each time the spark plug fires. The by-products of the gasoline and air explosion are primarily carbon monoxide, nitrous oxides (NOx) and unburned hydrocarbon by-products. Some of these products are forced around the piston rings and down into the crankcase; these are called blow-by products. These gases mix with the oil vapors in the crankcase and immediately begin to cook up some nasty substances that can, and will, harm your engine.

We must remove the blow-by products from the crankcase. But since 1965, we cannot just vent them to the atmosphere. So what do we do?

Until 1965, most cars and small trucks had a vent, often called a road draft tube, which vented the crankcase to the atmosphere. After 1965, legislation brought forward a governmentally mandated device to be installed on all vehicles. The positive crankcase ventilation (PCV) valve is a simple system that introduces filtered fresh air into the crankcase. The PCV valve uses the engine’s vacuum to pull air through the crankcase and reintroduce it back into the intake manifold system. This sends the uncombusted hydrocarbons and nitrous oxides that blew by the rings another chance for complete combustion, and in later vehicles, to be managed by the engine’s emission control system.

This system works great and is practically maintenance-free. However, a lack of knowledge coupled with the fact that the average driver does not open his engine hood at every fill-up, can lead to large problems. And, not knowing how and why the oil breathes can lead to expensive repair bills for your vehicle.

About the time we ceased handing out used oil for dust control, I learned that wine, like oil, needs to breathe. One summer during my youth, a friend and I realized that we could make wine from the locally grown oranges.

 Incidentally, there was a large commercial orange winery within two miles of my home. How hard could it be? We were too young to legally purchase wine, so we “borrowed” oranges for educational purposes from a grove next to my home. To begin the wine-making process, we juiced the oranges, filtered the pulp, and then placed the juice and yeast into three large five-gallon glass bottles.

Various PCV Valves

They were the kind of bottles in which spring water was once delivered. We tightly corked and even manufactured a rudimentary cage for the cork, like the ones we’d seen on champagne bottles. Too bad we were ignorant of safety valves or pop-off valves.

We stored the bottles in my friend’s attic, out of his parents’ sight. One fine day, the yeast and sugars from the juice performed as one might expect and blew the corks off the bottles, spraying rancid orange wine throughout my friend’s attic. The smell was awful. Our mothers were livid and it took us two days to scrub everything to get rid of that rotten smell. It was a simple mistake, but the consequences of our ignorance were severe.

The consequences of ignorance about CV systems can also be costly. The system is simple. As a professional mechanic, almost every week I see a malfunctioning PCV system literally grinding an engine to bits. The rubber hoses and grommets that are part of the system can swell and loosen their connection to the other parts of the engine. The results depend upon where the integrity of the connection fails. If the connection is loose and sucking air into the line between the air filter housing and the valve covers or other intake point, raw unfiltered air is introduced to the crankcase. This can grind bearings, overload the oil filter capacity and in general, make a junk pile of the engine. Many of the prematurely worn out engines I have seen can trace their failures to a long-term malfunction of the PCV system.

If the connection fails on the other side between the PCV and the intake manifold, raw blow-by products spew into the atmosphere. The results are the terribly messy, oil and dust-coated engine compartments that many of us have seen, and the release into the atmosphere of many aggressive pollutants.

The ignorance and lack of attention to detail made my first wine experience my last. Don’t let the lack of knowledge and disregard for the simple PCV on your car cost you many miles of service from your modern-day combustion engine. Either you or your mechanic can inspect this entire system in just a few minutes. Hose, grommet or PCV replacements often cost less than $20. Do yourself and the environment a favor – check and/or repair this vital system this week.

Inspect Your PCV System

Try this for yourself: Check under the hood for a white plastic sticker, approximately 6 by 3 inches. Listed on it are the engine size, emission systems in use, spark plug gap, timing information and other useful information. Part of the sticker looks like a road map with colored lines. Look for PCV, ignoring the strange acronyms, such as EGR, MAP or VSERV. If you can locate the PCV valve on the engine, follow the map and check all hoses and connections for swelling or cracking. Replace any parts found loose, cracked, swollen or coated with motor oil. In general, if there is no evidence of oil leakage, there should be no problem. Malfunctioning PCV valves can be the source of a leak and can cause leaks in other gaskets on your engine. If in doubt, see a professional.

Understanding the Differences in Engine Oils

Contrary to popular belief, there are major differences between passenger car motor oil (PCMO) and heavy-duty diesel oil. The main distinction is in the additive packages. PCMO has lower detergent and anti-wear (AW) additive levels. The AW additive alone can play havoc with components like catalytic converters. This is why you do not want to mix up these engine oils or use one in place of the other.

Additive Packages and Catalytic Converters

A catalytic converter is the large metal box bolted to the underside of your car. It has two pipes coming out of it, with one for the “input” and the other for the “output.” The converter’s input pipe is connected to the engine and brings in hot, polluted fumes from the engine’s cylinder head. The output pipe is attached to the tailpipe. As gases from the engine fumes move over the catalyst, chemical reactions occur, breaking apart (cracking) the pollutant gases and converting them into other gases that are safe enough to blow harmlessly into the air. Several lubrication professionals cannot distinguish passenger car motor oil from heavy-duty diesel engine oil.

Typically, there are two catalysts in a catalytic converter. One tackles nitrogen-​oxide pollution using a chemical reaction called reduction (removing oxygen). This breaks up nitrogen oxides into nitrogen and oxygen gases, which are essentially harmless because they already exist naturally in the air. The other catalyst works by an opposite chemical process called oxidation (adding oxygen) and turns carbon monoxide into carbon dioxide. Another oxidation reaction converts unburned hydrocarbons in the exhaust into carbon dioxide and water. In effect, three different chemical reactions are occurring at the same time. After the catalyst has done its job, what emerges from the exhaust is mostly nitrogen, oxygen, carbon dioxide and water (in the form of steam).

Some of the byproducts of combustion, including lead, zinc, phosphorus and sulfur, can severely cripple the converter’s ability to perform its job. Therein lies the first major difference between PCMO and heavy-duty diesel oil. Diesel engine oils have a higher anti-wear load in the form of zinc dialkyldithiophosphate (ZDDP). Catalytic converters in diesel systems are designed to handle this additive, but gasoline systems are not. This is one of the main reasons you don’t want to use diesel engine oil in your gasoline engine

	Gasoline		Diesel
Standard	From	To	From	To
API	SA	SN	CA	CJ-4
ILSAC	GF-1	GF-5	N/A	N/A
ACEA	A1 (A4)	A5	B1	B5

Effects of Switching Engine Oils

Viscosity is the single most important property of a lubricant. For engine oils, the selected viscosity must allow the oil to be pumpable at the lowest startup temperature the vehicle will experience while still protecting components at in-service temperatures.

Generally, diesel engine oil has a higher viscosity. If you were to put this higher viscosity oil in a gasoline engine, several problems might arise. The first issue would be heat generation from internal fluid friction. Heat affects the life of the oil in a negative way. For every 10 degrees C the temperature of the oil is raised, you cut the life of the oil in half.

Another problem with this higher viscosity oil is its low-temperature pumpability. During cold starts, the oil may be very thick and difficult for the oil pump to deliver to vital engine components like the lifter valley. This lack of oil at startup will lead to premature wear, as the components will interact without the benefit of lubrication until the engine temperature starts to increase.

Additive Effects on the Engine

Diesel engine oil has more additives per volume. The most prevalent are overbase detergent additives. These additives have several functions, but the primary ones are to neutralize acids and clean the oil in the sump. Diesel engines create a great deal more soot and combustion byproducts. Through blow-by, these find their way into the crankcase, forcing the oil to cope with them. When this extra additive load is put into a gasoline engine, the effects can be devastating to performance. The detergent will work as designed and will try to clean the cylinder walls. This can have an adverse effect on the seal between the rings and liner, resulting in lost compression and efficiency.

Reading Oil Labels

So how do you know if an oil has been formulated for a gasoline or diesel engine, or even the particular year the vehicle was made? When reading the oil’s label, look for the American Petroleum Institute (API) donut. In the top section of this donut will be the service designation. This designation will start with either an “S” (service or spark ignition) for gasoline engines or a “C” (commercial or compression ignition) for diesel engines. See the example above.

Other organizations have their own codes for the types of oils used in gasoline and diesel engines. They also align with the API’s standards. These include the International Lubricant Standardization and Approval Committee (ILSAC) and the Association of European Automotive Manufacturers (ACEA). API and ILSAC are based in the United States, while ACEA is in Europe. These organizations help to specify automotive and diesel engine oils throughout the world.

Other Considerations

There are many things to consider when choosing an engine oil for your car, including the weather conditions in which the vehicle will be operating. For instance, in the middle of winter, you want to select an oil that will stay sufficiently viscus to ensure it flows to the engine’s vital components. The oil’s viscosity is another critical factor for ensuring the engine’s moving parts are sufficiently separated to minimize wear. The oil’s additive package is also important. Too high anti-wear additive levels can cause your catalytic converters to clog prematurely, while excessive detergent additives can lead to piston blow-by, loss of compression and premature oil degradation. If you have doubts as to the type of oil you should be using in your vehicle, be sure to follow the manufacturer’s recommendations.

Retrofit your entire plant and monitor the health and level of your lubricants with Visual Oil Analysis products.

API Introduces New Diesel Engine Oil Standards

 

The American Petroleum Institute (API) is introducing two new standards to take into account the latest technology in diesel engines. API CK-4 and FA-4 will first appear in the API service symbol donut on Dec. 1, 2016. These new service categories improve upon existing standards by providing enhanced protection against oil oxidation, engine wear, particulate filter blocking, piston deposits, and degradation of low- and high-temperature properties.

 API CK-4 describes oils for use in high-speed, four-stroke-cycle diesel engines designed to meet 2017 model-year on-highway and Tier-4 non-road exhaust-emission standards as well as for previous model-year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 parts per million (ppm). However, the use of these oils with greater than 15 ppm sulfur fuel may impact exhaust after-treatment system durability and/or oil drain intervals.

CK-4 oils exceed the performance criteria of API CJ-4, CI-4 with CI-4 Plus, CI-4, and CH-4, and can effectively lubricate engines calling for those API service categories. When using CK-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval recommendations. Most truck manufacturers recommending API-licensed CJ-4 engine oils will likely recommend truck owners start using licensed API CK-4 oils as soon as they are available.

The API FA-4 standard designates certain lower viscosity oils specifically formulated for use in select high-speed, four-stroke-cycle diesel engines designed to meet 2017 model-year on-highway greenhouse gas (GHG) emission standards. Some engine manufacturers might recommend FA-4 oils for their previous model-year vehicles, but it is more likely that manufacturers will recommend the oils starting with the 2017 model-year engines. These oils are neither interchangeable nor backward compatible with API CK-4, CJ-4, CI-4 with CI-4 Plus, CI-4 or CH-4 oils. Therefore, you should heed the engine manufacturer’s advice for API FA-4 oils.

Applications and Benefits of Magnetic Filtration

Oil filtration in automotive and industrial machinery is essential to achieving optimum performance, reliability and longevity. Lubricant cleanliness is highly important and lubrication practitioners are provided with numerous options for filtering and controlling contamination, including disposable filters, cleanable filters, strainers and centrifugal separators. This article discusses the mechanism of particle separation and reviews the many applications of magnetic filters and separators in the lubrication industry today. A brief guide to commercial filtration products is also presented.

From its origin in the beneficiation of iron ores, the magnet has played a prominent role in the separation of ferrous solids from fluid streams. Even in the control of contamination from in-service lubricants and hydraulic fluids, magnetic separation and filtration technology has found a useful niche. Currently, there are a number of conventional and advanced products on the market that employ the use of magnets in various configurations and geometry.

Role of Magnetic Filters

Car owners, car mechanics, equipment operators, maintenance technicians and reliability engineers know the importance of clean oil in achieving machine reliability. Tribologists and used oil analysts are also aware that in some machines as much as 90 percent of all particles suspended in the oil can be ferromagnetic (iron or steel particles). Typically, one or both lubricated sliding or rolling surfaces will have iron or steel metallurgy. These include frictional surfaces in gearing, rolling-element bearings, piston/cylinders, etc.

While it is true that conventional mechanical filters can remove particles in the same size range as magnetic filters, the majority of these filters are disposable and incur a cost for each gram of particles removed. There are other penalties for using conventional filtration, including energy/power consumption due to flow restriction caused by the fine pore-size filter media. As pores become plugged with particles, the restriction increases proportionally, causing the power needed to filter the oil to escalate.

How do Magnetic Filters Work?

While a large number of configurations exist, most magnetic filters work by producing a magnetic field or loading zones that collect magnetic iron and steel particles. Magnets are geometrically arranged to form a magnetic field having a nonuniform flux density (flux density is also referred to as magnetic strength) (Figure 1).

Figure 1. Magnetic filter showing pattern
of flux distribution and the collected dirt.

Particles are most effectively separated when there is a strong magnetic gradient (rate of change of field strength with distance) from low to high. In other words, the higher the magnetic gradient, the stronger the attracting magnetic force acting on particles drawing them toward the loading zones. The strength of the magnetic gradient is determined by flux density, spacing and alignment of the magnets.

Various types of magnets can be used in these filters (see sidebar). Magnets used in some filters can have flux density (magnetic strength) as high as 28,000 gauss. Compare this level to an ordinary refrigerator magnet of between 60 and 80 gauss. The higher the flux density, the higher the potential magnetic gradient and magnetic force acting on nearby iron and steel particles.

While there are many configurations of magnetic filters and separators used in process industries, the following are general classifications for common magnetic products used in lubricating oil and hydraulic fluid applications.

Magnetic Plug. The most basic type of magnetic filter is a drain plug (Figure 2), where a magnet in the shape of a disc or cylinder is attached to its inside surface (typically by adhesion). Periodically, the magnetic plug (mag-plug) is removed and inspected for ferromagnetic particles, which are then wiped from the plug.

Figure 2. Drain Plug Filter

Today, such plugs are commonly used in engine oil pans, gearboxes and occasionally in hydraulic reservoirs. One useful advantage of mag-plugs relates to examining the density of wear particles observed as a visual indication of the wear rate occurring within the machine over a fixed period of running time. The appearance of these iron filings on magnets are often described in inspection reports using terms such as peach fuzz, whiskers or Christmas trees. If one normally sees peach fuzz, but on one occasion sees a Christmas tree instead, this would be a reportable condition requiring further inspection and remediation. After all, abnormal wear produces abnormal amounts of wear debris, leading to an abnormal collection of debris on magnetic plugs.

Rod Magnets. While magnetic plugs are inserted into the oil below the oil level (for example, drain port), rod magnets may extend down from reservoir tops (Figure 3), special filter canisters (Figure 4) or within the centertube of a standard filter element.

Figure 3. Tank Magnet  

                                                             

  Figure 4a. Canisters

                                    

Figure 4b. Low-efficiency Collection Pot

These collectors consist of a series of rings or toroidal-shaped magnets assembled axially onto a metal rod. Between the magnets are spacers where the magnetic gradient is the highest, serving as the loading zone for the particles to collect. Periodically the rods are removed, inspected and wiped clean with a rag or lint-free cloth. A conceptual example of a particular rod magnet filter is shown in Figure 1. When the rod is removed, the sheath or shroud can be slid off the magnet core to remove the collected debris. This debris can then be prepared for microscopic analysis to aid in assessing machine condition.

Flow-through Magnetic Filters.
Figure 5 illustrates an example of a commercially available flow-through filter.

Figure 5. Flow-through Filter

In this configuration, sold by Fluid Condition Systems under the MAGNOM trademark, the magnets are sandwiched between metal collection plates that have specific flow slots (Figure 6).

Figure 6. Collection Plates

As fluid passes through the slots, ferromagnetic particles accumulate in the gap between the plates. However, they do not interfere with flow (clogging), or risk particles being washed off by viscous drag. One advantage of flow-through magnetic filters is the large amount of debris they hold before cleaning is required. The cleaning process typically involves removing the filter core and blowing the debris out from between the collection plates with an air hose.

Supplier	Plug	Rod	Flow-through Filters	Spin-on Filter Wraps
C.G. Enterprises Automotive Inc.	x
Control Power Co.	x
General Plug and Manufacturing	x
Great Lakes Hydraulics Inc.	x
Halex Development and Distribution, LLC				x
Hydro-Craft Inc.		x
Kebby Industries, Inc.		x
Lisle Corporation	x
Magna-Guard, Inc.				x
Parker Hannifin		x	x
MAGNOM			x
S.G. Frantz Company			x
One Eye Industries, Inc.	x	x	x	x
Tiger Mag / FilterMag			x
Turbo-mag				x
Twinmagnet / SynLube				x
Vescor Corporation	x

Spin-on Filter Wraps.

There are several suppliers of magnetic wraps, coils or similar devices intended for use on the exterior of spin-on filter canisters (Figures 7a-c). Spin-on filters are commonly used in the automotive industry but are also utilized in a number of low-pressure industrial applications. These wraps transmit a magnetic field through the steel filter bowl (can) in order for ferromagnetic debris to be held tightly against the internal surface of the bowl, allowing the filter to operate normally while extending the service life. Unlike the conventional filter element, the magnetic filter wrap can be used repeatedly.

7a. Combo Mechanical and Magnetic Filters

7b. Combo Mechanical and Magnetic Filters

7c. Combo Mechanical and Magnetic Filters

8. Combo Mechanical and Magnetic Filters

Factors Influencing Magnetic Separating Action Combo Mechanical and Magnetic Filters

There are a variety of magnets and ways in which magnetic filters and separators can be configured in a product’s design. In fact, there is much more to their performance than simply the strength or gradient of the magnetic field. For instance, the size and design of the flow chamber, total surface area of the magnetic loading zones, and the flow path and residence time of the oil are all important design factors. These factors influence the rate of separation, the size of particles being separated and the total capacity of particles retained by the separator.

The magnetic force acting on a particle is proportional to the volume of the particle, but is disproportional to the diameter of the particle (magnetic force varies with the cube of the particle’s diameter). For instance, a two-micron particle is eight times more attracted to a magnetic field than to a one-micron particle. This means large ferromagnetic particles are disproportionately easier to separate from a fluid compared to smaller particles.

The separating force is proportional to the magnetic field gradient and also to the particle magnetization (magnetic susceptibility). Particle magnetization relates to the degree to which the particle’s material composition is influenced by a magnetic field. The most strongly attracted materials are particles made of iron and steel, however, red iron oxide (rust) and high-alloy steel (for example, stainless steel) are weakly attracted to magnetic fields. Conversely, some nonferrous compounds such as nickel, cobalt and certain ceramics are known to have strong magnetic attraction. Materials that cannot be picked up with a magnet (such as aluminum) are called paramagnetic substances.

There are also competing forces which resist particle separation from the fluid. One such force is oil velocity which imparts inertia and viscous drag on the particle in the direction of the fluid flow. Depending on the design of the magnetic filter, the fluid velocity may send the particle on a trajectory toward or away from the magnetic field or perhaps in a tangential direction.

The competing viscous force is also proportional to both the particle’s diameter and the oil viscosity. If the particle’s diameter or the oil’s viscosity doubles, then the hydrodynamic frictional drag doubles accordingly (resistance to separation). Complicating the situation further, as mentioned above, the magnetic attraction increases by a factor of eight when a particle’s diameter doubles, while the competing viscous drag sees only a 2X multiple. This further emphasizes the fact that larger particles are more easily separated than small particles, even in an environment of considerable viscous drag.

Particle capture efficiency by magnetic technology can be narrowed down to these fundamental factors:

1. Particles that are the easiest to separate are large (100 microns vs. 5 microns) and highly magnetic (for example, iron and low-alloy steel).
2. The fluid conditions that best facilitate the separation of magnetic particles are low oil viscosity (ISO VG 32 vs. ISO VG 320 for instance) and low oil flow rate (2 GPM vs. 50 GPM). Even extremely small, one-micron particles can be separated from the oil if both of these fluid conditions exist concurrently.
3. The most effective magnetic filters employ high-flux magnets and are arranged in such a way that a high-gradient magnetic field develops.

Pros and Cons of Magnetic Filters

The decision to use magnetic technology in a given application depends on various machine conditions and fluid cleanliness objectives. These include the expected concentration of ferrous particles, type of oil used, operating temperature, surge flow and shock and machine design. Because of the numerous commercial products, configurations and applications, certain items on the lists of advantages and disadvantages may not apply. Nonetheless, this list can serve as a starting point for making the decision whether magnetic technology is a good choice in a given application:

Possible Advantages

• Reusable Technology – The cost of removing a gram of particles from the oil with magnetic technology is low compared to disposable filters.
• Limited Flow Restriction – Unlike conventional filters, most magnetic filters exhibit little to no increase in flow restriction (pressure drop) as it loads with particles. While conventional filters can go into bypass when they become plugged with particles, magnetic filters (including mag-plugs and rods) continue to remove particles and allow oil flow. For instance, most diesel and gasoline engines provide no indication of a filter that has gone into bypass. In such cases, the oil may go for an extended period of time without being filtered. Common causes of premature plugging of engine filters include coolant leaks, poor combustion, poor air filtration and overextended oil drains.
• Extended Life of Conventional Filters – When used in conjunction with conventional mechanical filters (Figure 8), an increase in effective filter service life may be experienced. In certain cases, two to three times life extension may be experienced.
• Improved Reliability of Electro- hydraulic Valves – Servovalves and solenoid valves are adversely affected by particles that are magnetic (iron and steel) due to the electromagnets deployed when actuating these valves. The continuous and efficient removal of these particles by magnetic filters can substantially enhance the reliability of these valves.
• Lower Risk of Oil Oxidation – Iron and steel particles are known to promote oil oxidation by their catalytic properties. Premature oil oxidation can lead to varnish, sludge and corrosion. Everything else being equal, the continuous and efficient removal of iron and steel particle by magnetic filters should have a positive impact on oil service life, and over time, reduce oil consumption if oil is changed on condition.
• Enhanced Wear Particle Identification – Traditionally, wear particle identification is performed microscopically by examining particles extracted from oil samples (analytical ferrography). Those particles that have evaded filters have often been reworked (comminution) by traveling through heavily loaded rolling and sliding dynamic machine clearances. Once ground up, crushed and pulverized, they are more difficult to analyze to determine the source location, cause and severity of wear. However, particles removed from mag-plugs, magnetic rods and magnetic filters are often in their original “virgin” state which can greatly enhance the accuracy of machine condition analysis.
• Quick Wear Metal Inspections – Mag-plugs and rods can be removed for visual inspection (daily, weekly, etc.) without stopping the machine or removing a filter. They provide a dual service of contaminant removal and condition monitoring (from the density of wear particles observed).
• Oil Flow Not Required – Many machines are lubricated by oil splash, bath, flingers, slingers and paddles. Without access to a pump and oil flow, conventional onboard filters cannot be used to keep the oil clean and optimize machine reliability (reduce wear) and lubricant service life (reduce oil oxidation). However, magnetic plugs and rods do not require oil to flow in pipes and lines. They require the oil only to agitate and circulate in a sump, reservoir or oil pan. This movement causes these particles to migrate to a loading surface of the magnetic separator.
• Can be Used in Gravity Flow Drain Lines – Most wear metal production comes from the business end of a machine (bearings, gears, cams, etc.). Oil often returns to tank down drain lines and headers (flooded or partially flooded) by gravity. Due to the lack of oil pressure, it is nearly impossible to locate fine filtration on gravity drains to catch wear debris before it enters the reservoir. However, magnetic filters, rods and plugs generally do not restrict flow, enabling these particles to be quickly and conveniently removed directly in oil drains.

Possible Disadvantages

• Detached Particle Agglomerations – A common risk associated with using magnetic separators is the possibility of particles becoming detached from the magnet and washed downstream in mass, potentially entering a sensitive component. This concern is reduced if the magnetic separator is located on a drain line or if a conventional filter is positioned downstream to trap migrating debris. Risk of debris being washed off is highest under surge flow conditions, cold starts, shock, high oil viscosity and/or high oil flow rates.
• Magnetized Transient Particles – Adding to the risk of particle washoff is the chance of these particles becoming magnetized while they were attached to the permanent magnet. After floating downstream, they might adhere magnetically to frictional surfaces such as bearings, causing wear. They could also lodge into narrow flow passages, orifices, glands and oilways, thus restricting flow.
• Nonmagnetic Particles Remain Unchecked – Indeed, magnetic separators will have little effect on controlling nonferrous particles composed of silica, tin, aluminum or bronze. Other types of filters and separators must be used.
• Cleaning Requirement – Unlike conventional filter elements that are thrown away after becoming plugged, magnetic filters are reusable and therefore must be cleaned. The cleaning procedure varies but typically is messy and involves the use of an air hose. Specific cleaning safety precautions must be taken. Magnetic rods and plugs generally need to be wiped clean only at each service interval.
• Separation is not by Size-exclusion Mechanics – As previously discussed, separation is based on physics considerably different from size-exclusion – the method which defines the performance of conventional mechanical filters. Instead, the capture efficiency of magnetic separators is based on many factors including the collective influence of particle size, magnetic susceptibility, flow rate, viscosity and magnetic field gradient.

As such, magnetic filters are not known for having well-defined micronic particle separation capability. Therefore, it is important to determine what micron filter rating is needed by the tribological components in the system, considering the oil viscosity, fluid flow rate through the filter, the properties of the challenge particles, etc. Experience shows that most modern hydraulic components need protection of at least five microns or greater. Studies conducted some 20 years ago at the Fluid Power Research Center at Oklahoma State University for the Office of Naval Research showed that no magnetic filter at that time could satisfy this requirement when used alone. In such cases, the best choice might be a combination of conventional and magnetic filters.

Types of Magnets

NdFeB (Neodymium-Iron-Boron) This is the strongest in magnetic strength of all the magnets known to mankind. Neodymium, with a number 60 on the periodic table, was first thought to be a rare earth element, due to its inclusion in the “rare earth” elements between 57 and 71 on the periodic table. NdFeB was first developed and commercialized in the mid 1980s. Over the years, the strength of this composition has increased due to new developments.

SmCo (Samarium Cobalt)
Also being one of the “rare earth” elements, Samarium Cobalt can produce magnetic strength near that of NdFeB. It became available in the 1970s but was rarely used. Due to its expensive composition, fragility and difficulty to manufacture, it is used only for its benefits of being able to withstand high temperatures and corrosion.

Ferrite (Ceramic)
Today’s refrigerator magnet – ceramic magnets with Barium or Strontium Ferrite – is the most common of all magnets. It is considerably inexpensive but it contains a lower strength compared to the other magnets. Developed in the 1960s, it was the “useful” magnet, used everywhere. This type of magnet is cost-effective and resistant to corrosion and demagnetization.

AlNiCo (Aluminum-Nickel-Cobalt)
One of the first magnets developed after plain steel, this magnet has a lower strength rating. It is sensitive to demagnetization and can be destroyed if stored incorrectly or if it comes in contact with Neodymium-Iron-Boron. It has excellent machinability and has about half the strength of a ceramic magnet. Reference: www.wondermagnets.com

Best Applications for Filters and Separators

It is logical that the leading applications for magnetic separators are those where a high percentage of the particle contamination is ferromagnetic and the conditions favor a successful performance of a properly selected and installed magnetic filter or separator. As previously discussed, low oil viscosity combined with low flow rate help to facilitate the separation process (where applicable). It’s a good idea to review the lists of advantages and disadvantages in regards to each application and separator type (mag-plug, rod, flow-through, wrap) considered. Possible uses for magnetic technology include the following:

• Gearboxes (including final drives, differentials, etc.), both forced-circulating and splash-fed
• Large diesel engines, especially where the full-flow filter may prematurely go into bypass without indication
• Any machine with ferrous frictional surfaces but no forced oil circulation with filtration
• Applications where the use of magnetic filters will substantially extend the life of conventional filters already in use
• Applications where iron particles are known to be a major contributor to oil oxidation problems (particularly hot running machines)
• Hydraulic systems, particularly those using electrohydraulic valves
• In situations requiring better precision in recognizing abnormal wear particle generation (and wear particle type)

Unearth the benefits of GG Friction Antidote – An investment that pays off and your benefits at a glance:

Innovative tribological solutions are our passion. We’re proud to offer unmatched friction reduction for a better environment and a quick return on your investment. Through personal contact and consultation, we offer reliable service, support and help our clients to be successful in all industries and markets.

Profitability:

Switching over to a high-performance lubricant pays off although purchasing costs may seem higher at first, less maintenance and longer vehicles/machinery parts lifecycle may already mean less strain on your budget in the short to medium term.

Continuous production processes and predictable maintenance intervals reduce production losses to a minimum. Consistently high lubricant quality ensures continuous, maintenance-free long-term lubrication for high plant availability. Continuous supply of fresh GG Friction Antidote treated lubricant to the lubrication points keeps friction low and reduces energy costs.

Safety:

Longer lubrication intervals reduce the frequency of maintenance work and the need for your staff to work in danger zones. Lubrication systems can therefore considerably reduce occupational safety risks in work areas that are difficult to access.

Reliability:

GG Friction Antidote treated lubricants ensure reliable, clean and precise lubrication around the clock. Plant availability is ensured by continuous friction reduction of the application. Lubrication with GG Friction Antidote treated lubricants help to prevent significant rolling bearing failures.

Need a good ROI? How about 3,900%?

It may sound too outrageous to be true, but the Institute of Mechanical Engineers estimates every $1,000 spent on proper lubrication yields $40,000 in savings.

INSTANT ROI FOR OPTIMIZING YOUR LUBRICATION REGIMEN

How many kilometers do you travel monthly?

How many hours do you clock monthly?

How many litres of fuel do you consume monthly?

What’s the cost of fuel to you monthly?

How many kilometers or hours do you run per oil change?

How many litres of oil do you consume per oil change?

       What’s the cost of oil to you monthly?

What’s the cost of oil filters per oil change to you?

What’s the cost of grease to you monthly?

What’s the cost of fuel filters per oil change to you?

What’s the cost of air filters per oil change to you?

What’s the average frequency of vehicle/machinery replacement to you?

What’s the cost of vehicle/machinery replacement to you?

Would you like to lower your operating costs, improve uptime and increase your company’s profits?

Let’s do the math together … Learn more >>

The information in this literature is intended to provide education and knowledge to a reader with technical experience for the possible application of GG Friction Antidote.  It constitutes neither an assurance of your vehicle/machinery optimization nor does it release the user from the obligation of performing preliminary tests with GG Friction Antidote. We recommend contacting our technical consulting staff to discuss your specific application. We can offer you services and solutions for your heavy machinery and equipment.

Locate A GG Friction Antidote Dealer