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A Simple Way To Fight Cylinder-Liner Cavitation

Written by Charleen

A SIMPLE WAY TO FIGHT CYLINDER-LINER CAVITATION

In extreme cases, cylinder-liner cavitation in diesels can allow oil and coolant to mix. Then it’s just a matter of time until engine failure. Here’s what you can do to help ensure that doesn’t happen.

Most diesel engines are designed with replaceable cast-iron cylinder liners that are pressed into the engine block. While this doesn’t apply to turbodiesel pickups, it affects heavy-duty over-the-road trucks and other diesels. The piston moves up and down inside the liner, while a jacket of coolant surrounds the outside of the liner to cool the engine.

How cylinder-liner cavitation occurs

When the engine is running, the pistons move vertically inside their liners several thousand times per minute. Meanwhile, the rotary motion of the crankshaft applies a thrust force through the connecting rods to the piston. These contradictory movements cause the pistons to hammer the liners, causing significant vibration, similar to the effect of ringing a bell. This vibration can cause air bubbles to form in the coolant surrounding the liner.

When the bubbles rupture, they direct a high-pressure stream of coolant at the liner. Like a rushing river carving away a canyon wall, the coolant can erode the liner until cavities form. Left unchecked, these cavities can keeping growing and eventually penetrate the liner, allowing oil and coolant to mix. Once that happens, it’s only a matter of time before the engine fails.

Prevention is the best practice when it comes to cavitation. That task falls on the engine coolant, and there are two ways formulators typically design engine coolant to fight cavitation.

How Cylinder Liner Cavitation Occurs
Imploding bubbles direct high-pressure
coolant toward the cylinder liner, creating
cavities through which the coolant can enter
and mix with oil, damaging the engine.

The old-fashioned way

For years, formulators have added metallic salts, like nitrites and molybdenates, to coolant that attach themselves to the liner and form a sacrificial layer. When the coolant bubbles implode, the metallic salts absorb the pressure and break off from the liner surface rather than the metal itself. Metallic salts naturally deplete over time, meaning motorists must replenish them periodically by adding a supplemental coolant additive (SCA) to the coolant reservoir, typically midway through the service interval. Unfortunately, this is often overlooked.

The better way

The trend in the coolant market – and the strategy we use at AMSOIL – is to eliminate adding an SCA by formulating coolant with organic acid technology (OAT). The chemistry of OAT coolants passivates the liner surface, which coats it in a thin, inert layer that provides protection against cavitation and corrosion. Unlike old-fashioned metallic salts, the additives in OAT coolants last much longer, meaning you don’t have to replenish the system with an SCA. Modern OAT coolants also help fight problems associated with old fashioned “green” coolants, like scaling and additive drop-out (which leads to “slime” in your coolant system) due to incompatibility issues.

Coolant Maintenance is Key – Don’t forget about the most forgotten system

Aside from using an OAT coolant, it’s good practice to check your coolant level periodically. Also, make sure to check the pH and glycol levels annually. Glycol is important to the level of freeze protection and the coolant’s boiling point. Over time, the water can evaporate from the system and increase glycol concentration, throwing off the coolant’s balance. Perform fluid analysis once a year for best performance. We offer that service through Oil Analyzers INC. (www.oaitesting.com). We also offer antifreeze test strips (G1165).

Using AMSOIL Heavy Duty Antifreeze & Coolant (ANTHD) and taking care of your diesel’s cooling system go a long way toward avoiding the financial pain of fixing an engine ruined by cylinder-liner cavitation.

We keep this one in the Omaha store due to requests. If you need more than a case of four we can have it delivered next day or shipped to your home.

  • Pre-mixed 50/50 with high-purity water.
  • Fully formulated: DOES NOT require the use of supplemental coolant additives (SCAs) or excenders.
  • All-organic formulation is further enhanced with anti-scalant, anti-fouling and water-pump lubrication additives.
  • Phosphate-, nitrate-, nitrite-, silicate-, borate and amine-free.
  • Boil-over protection up to 265 F (129 °C) with a 15 psi radiator cap.
  • Freeze protection down to – 34 F (-37 °C)
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Engine start-stop technology – Major Wear Issues

Written by Charleen

Engine start-stop technology can increase bearing wear

Use only the best quality oil in these engines as the crankshaft needs to float. Even the “so called synthetics” don’t dampen the metal to metal issues mentioned below nearly as well as AMSOIL and you can tell due to the reduction in vibration or more consistent oil pressure as you rack up miles.

Yet another reason to upgrade to AMSOIL synthetic motor oil.

Matt Erickson | DIRECTOR, TECHNICAL PRODUCT MANAGEMENT

Nearly every technology shaping the auto industry can be traced to one goal: increased fuel economy. Engine start-stop technology is one more tool automakers have in their arsenals to ensure today’s vehicles meet tomorrow’s tightening fuel-economy regulations.

In principle, start-stop technology is simple: the engine automatically shuts off while you’re idling and restarts when you take your foot off the brake. This reduces fuel wasted while idling. Automakers introduced different startstop systems in the late ‘70s and early ‘80s; however, drivers found them awkward and unworthy of the higher vehicle price. Today’s start-stop systems are less obtrusive and are available on vehicle models from most automakers.

Should be called Metal to Metal Contact Engine

That’s not to say they’re without detractors. In fact, some automakers have installed off switches that allow motorists to disable the feature in response to negative driver feedback. But, despite their pitfalls, they’re likely not going anywhere. Consider these statistics:

  • According to bearing manufacturer MAHLE*, U.S. vehicles burned 3.9 billion gallons of gasoline while idling in 2017.
  • Buick* reports that engines with start-stop technology increase fuel economy 4-5 percent using the EPA test cycle.

Automakers leap for joy over minuscule fuel-economy gains, so you can bet they’re going to stick with anything that may provide a 4-5 percent boost.

So, what does that have to do with motor oil?

Maybe you’re aware that most engine wear occurs during cold starts. Well, engine wear occurs during warm starts, too, like every time an engine equipped with start-stop technology restarts.

We have to get technical to understand why.

The crankshaft spins thousands of times per minute in a running engine. As it spins, oil flows through tiny openings in the crankshaft journals and fills the spaces between the journals and main bearings. The crankshaft literally floats on an oil film and doesn’t contact the bearings. We call this scenario hydrodynamic lubrication. In this regime, the bearings suffer little wear and last a long time.

Run of the mill oils (95% on the shelf) are not going to provide protection with this condition

Stopping the engine, however, reduces oil film thickness. The crankshaft settles onto the bearing surfaces rather than floats over them. The oil film thickness shrinks to about the same thickness as the surface roughness of the crankshaft. This is called boundary lubrication. Starting the engine allows the microscopic peaks on the metal surfaces to contact and cause wear until the oil film has been reestablished and the crankshaft is once again floating over the bearings. This is where the oil’s additives play a huge role in protection.

Granted, only minimal wear may occur each time the engine is started. It’s not a big concern in a properly maintained traditional engine using a good oil. But what if you greatly increase engine startstop cycles?

Consider another statistic from MAHLE:

  • Start-stop cycles in equipped engines may triple over the engine’s lifetime compared to traditional engines.

That means three times more engine starts, three times more instances of boundary lubrication and three times more exposure to increased bearing wear.

Bearing wear can snowball out of control, too. Metal particles can break off and populate the oil. The bearing surface becomes rougher, encouraging adhesive wear in which peaks on metal surfaces grab and tear the mating surfaces. Eventually the crank journal and bearing can weld together, ruining the bearing.

This all points to a simple directive: make sure your customers with engines using start-stop technology are using AMSOIL synthetic motor oil to guard against bearing wear. Oil film thickness shrinks when engines start from a dead stop, placing even more importance on oil additives to maintain protection. Since engines equipped with start-stop technology spend so much more time under boundary lubrication, it’s vital to use an oil with superior film strength and additive quality. AMSOIL Signature Series Synthetic Motor Oil delivers. It provides 75% more engine protection against horsepower loss and wear** to help protect today’s advanced engines.

This is especially needed in vehicles calling for 0W-20, 5W-20 and 0W-16.

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Ask AMSOIL: Should I Use Racing Oil in my Daily Driver?

Written by Charleen

I Drive Aggressive: Is Racing Oil a better choice for my Daily Driver?

Motorists who are passionate about engine protection and performance can easily succumb to the following line of reasoning:

1) Racing engines are more severe than my engine.

2) Racing engines use racing oil.

3) Therefore, I should use racing oil in my vehicle for best protection.

It’s true that the average racing engine creates operating conditions more severe than the average passenger car engine. However, that’s not to say that modern engines aren’t tough on oil, too.

Increased heat and stress

The turbocharged, direct-injection engines in modern vehicles generate increased heat and contaminants compared to their predecessors. Motor oil bears the brunt of the added stress. That’s why industry motor-oil specifications keep growing tougher and automakers are increasingly recommending synthetic oils to meet these strict performance specs.

Racing creates tougher operating conditions

Racing, however, is a whole different animal. The powerful, modified engines in racing vehicles produce extreme heat and pressures beyond the capabilities of the average car or truck. A 900-hp Pro 4×4 off-road racing truck can produce engine temperatures of more than 300ºF (149ºC). Engine temperatures in a typical passenger car/light truck fall somewhere between 195ºF and 220ºF (90ºC – 104ºC). The difference is even more striking when you consider that the rate of motor oil oxidation (chemical breakdown) doubles for every 18ºF (10ºC) increase in oil temperature.

The tremendous shearing forces the oil bears as it’s squeezed between the interfaces of the pistons/rings and cam lobes/lifters pose another problem. The pressure can tear apart the molecular structure of the oil, reducing its viscosity and film strength.

Racing oil must be formulated differently to protect these demanding engines. Even so, it doesn’t mean you should order a case of AMSOIL DOMINATOR® Synthetic Racing Oil for your car.

Racing oils are changed more frequently

Why? For starters, racing oils are changed frequently. Most professionals change oil every couple races, if not more frequently. For that reason, racing oils are formulated with a lower total base number (TBN) than passenger car motor oils. TBN is a measure of the oil’s detergency properties and its ability to neutralize acidic byproducts. Oils with longer drain intervals have higher TBNs. AMSOIL Signature Series Synthetic Motor Oil features a TBN of 12.5 to enable its 25,000-mile/one-year drain interval. In contrast, DOMINATOR Synthetic Racing Oil has a TBN of 8 since it should be changed more frequently. As great as it performs on the track, DOMINATOR is not what you want in your engine when you’re driving thousands of miles and several months between oil changes.

Second, you want to use an oil in your daily driver that excels in several performance areas:

  • Wear protection
  • Long oil life
  • Maximum fuel economy
  • Engine cleanliness
  • Corrosion protection
  • Oxidation resistance
  • Easy cold-temp starts

Motor oil additives produce many of these benefits. For example, anti-oxidant additives fight high heat and extend oil service life. Anti-wear additives interact with the metal surfaces of engine parts and guard against metal-to-metal contact. Many additives form layers on metal surfaces. That being the case, they compete for space, so to speak.

Racing oils use different additives

Racing oils are often formulated with a heavy dose of friction modifiers to add lubricity for maximum horsepower and torque. The boosted level of additives meant to increase protection and performance during a race doesn’t leave room in the formulation for additives found in passenger car motor oils that help maximize fuel economy, fight corrosion or improve cold-weather protection.

Achieving the tasks of a passenger car motor oil requires a finely balanced formulation. Too much or too little performance in one area can negatively affect other areas – and the oil’s overall protection and performance. The list of tasks required of a racing oil, however, is much shorter.

The right tool for the right job is an axiom with which most are familiar. The same holds for motor oil. It’s best to leave racing oil to competition engines and use a properly formulated passenger car motor oil for your daily vehicle.

To find the right oil for your vehicle, use the AMSOIL Product Guide.

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Small engine won’t start? Identifying the Cause.

Written by Charleen

Small engine won’t start?

Bad gas is the number-one reason, and here’s how to prevent it.

Len Groom | TECHNICAL PRODUCT MANAGER, POWERSPORTS

In northern Minnesota, where I live, the temperature occasionally breaks 80ºF (27ºC) in the summer. When it does, it’s time to fire up my Jet-Skis* and hit the lake. The last thing I want to do on a sunny summer day is mess around with equipment that refuses to start or run properly.

Bad gasoline is the number-one reason seasonal equipment starts hard or runs rough. Over time, gasoline changes, leaving behind gums, varnish and other solids that foul the fuel system and prevent gas from flowing into the combustion chamber. In severe cases, gasoline can change so dramatically that it no longer ignites.

Gasoline is predominantly a mixture of carbon and hydrogen atoms bonded together into energy-dense hydrocarbons. Like conventional base oils, it’s derived from crude oil via a distillation process that uses heat, pressure and other catalysts to create different fractions. Gasoline is comprised of hydrocarbons that are lighter than those found in, for example, diesel fuel or conventional base oils. Refiners add ethanol to the formulation, typically 10 percent, but as high as 85 percent.

Time Takes Its Toll – You Must Treat Gasoline

Time, however, takes its toll on gasoline. Exposure to heat, humidity, atmospheric pressure, oxygen and other variables degrade fuel.

In addition to gums and varnish becoming more concentrated and less soluble as lighter hydrocarbons evaporate, gas is continually oxidizing, which further contributes to varnish and other gunk. Gasoline oxidizes more quickly than motor oil and its negative effects are more immediately noticeable. That’s why it’s important to use high quality gas and store it in approved containers where air infiltration is limited, like inside a ventilated garage or shed, and not in the back of your truck or under the deck.

Meanwhile, ethanol added to gasoline at the refinery can absorb water from the atmosphere, which can lead to phase separation, which occurs when ethanol and gas separate, much like oil and water. Ethanol that has absorbed enough moisture and has sat long enough can foul the fuel system and prevent the engine from starting.

AMSOIL Fights Corrosion

AMSOIL provides corrosion protection Sea Foam® Motor Treatment can’t match, helping maintain power and performance and keeping metal looking like new even when subjected to salt water.  ?

? Based upon independent testing of AMSOIL Gasoline
Stabilizer obtained Nov. 8, 2018 and Sea Foam Motor
Treatment purchased Oct. 25, 2018 in a modified NACE
TM0172 using synthetic sea water per ASTM D665 part B.

This all sounds dire, but it’s nothing treating your gasoline with AMSOIL Gasoline Stabilizer (AST) can’t solve. Gasoline Stabilizer keeps fuel fresh up to 12 months. AMSOIL Quickshot® (AQS) stabilizes gasoline during short-term storage up to six months, in addition to providing potent cleaning benefits and protection against ethanol issues.

What does stabilizer do?

That explanation may suit some people, but this is Tech Talk, so let’s look at the chemistry behind gasoline stabilizers.

You’ve probably heard terms like “free radicals” and “antioxidants” in relation to your health. A free radical is an unpaired electron, and most are unstable and highly reactive. They can either donate an electron to, or accept an electron from, other molecules. This starts a chain reaction that can lead to oxidative stress and cell damage. Left unchecked, free radicals can lead to health problems, like cardiovascular disease and cancer. To help fight free radicals, we should eat plenty of foods rich in antioxidants, which lessen their effects. Antioxidants can “donate” an electron to free radicals or trap them, effectively reducing their instability without becoming unstable themselves. Antioxidants aren’t silver bullets, but they go a long way toward improving our health.

By analogy, gasoline stabilizer is an antioxidant for your gasoline. It disrupts the free-radical-induced chain reaction that causes gas to oxidize and form varnish and gums. Some stabilizer products, like Quickshot, also contain chemistry that increases solvency and breaks down existing varnish, helping clean a dirty carburetor and restore performance. As shown, Gasoline Stabilizer also fights corrosion better than Sea Foam Motor Treatment.

Neglecting to stabilize your gas can lead to all sorts of headaches when it’s time to remove your lawnmower, generator, string trimmer or Jet-Ski from storage. For best results, stabilize your gasoline all year long. That’ll ensure your equipment is ready to roll when you are.

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