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Don’t Let Extreme Heat Sideline Your Motorcycle

An Oil to Resist Thinning from Extreme Heat and Mechanical Activity

Extreme summer heat combined with slow-moving rally or parade traffic can pose big problems for you and your motorcycle.

As heat intensifies, motor oil loses viscosity and becomes thinner. The oil can become so thin that the engine loses oil pressure, causing the oil-pressure gauge to bottom out. You may hear increased valvetrain and gear noise as parts clatter together. A good rider knows not to ride with no oil pressure, so he or she will shut down the bike and sit alongside the highway (or push the bike) until the engine cools enough to restore oil pressure.

Decreased airflow stresses oil

Air-cooled V-twins get plenty hot on their own, but riding in slow moving traffic makes it worse. Crawling along barely above idle doesn’t generate enough airflow to cool the engine. Add to that the blazing sun reflecting off the asphalt, and it’s a recipe for trouble. In extreme dyno testing designed to create heat, we’ve seen cylinder temperatures in a 2012 Harley-Davidson* Street Bob* as high as 383°F (195°C).

It’s up to the motor oil to protect the engine despite the intense heat; however, oil becomes thinner as it heats up. If it becomes too thin, it can fail to form a lubricant film of enough thickness and strength to prevent metal components from contacting during engine operation and wearing out. Once the lubricant film fails, it falls on the anti-wear additives to prevent wear. They form a sacrificial layer on components to keep them from contacting. But additives are designed to deplete with time and use. Once they wear out, your engine isn’t protected in this scenario.

Heat breaks down oil faster

The rate at which oil oxidizes, or chemically breaks down, doubles for every 18°F (10°C) increase in lubricant temperature. Oxidation occurs when oxygen molecules attack oil molecules and result in a chemical reaction that leads to harmful byproducts, like sludge and varnish. The faster the oil oxidizes, the sooner it wears out and requires changing.

Ride Hard. Run Cool.®

AMSOIL Synthetic V-Twin Motorcycle Oil uses high-quality synthetic base oils that naturally resist thinning due to extreme heat and mechanical activity better than conventional base oils. As a result, it forms a thick, strong lubricating film on engine components despite the intense heat. Although any oil will become thinner in extreme heat, riders who use AMSOIL Synthetic V-Twin Motorcycle Oil won’t see their oil-pressure gauges bottom out, providing the confidence they need to keep riding after others have shut down their bikes and started pushing.

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*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.

Should I Warm Up My Motorcycle Before Riding?

Should I Warm Up My Motorcycle Before Riding?

As soon as you crawl out of bed tomorrow morning, try this experiment: run outside and sprint down the street. Aside from embarrassment over your jammies (or lack thereof), how do you suppose you’ll feel?

Your motorcycle likewise needs to warm up a bit before hitting the street. Many folks at AMSOIL love anything to do with an engine, including motorcycles. So to get the technical details explaining why, I consulted a few of our resident bikers. They provided two main reasons for letting your bike warm up before riding.

1) Help avoid piston scuffing

Metal expands when it’s heated, and anyone who’s sat astride a motorcycle knows they make serious heat. Subjecting a cold piston to extreme heat and friction without first allowing it to warm up can cause rapid piston expansion and scuffing.

John Skuzinski, AMSOIL Mechanical Test Development Manager, says this:

“Optimal parts ??clearances inside the engine are not achieved until normal operating temperatures are reached. If clearances are less than normal due to low engine temps, and the throttle demands the engine goes to work spontaneously, internal temperatures can rise very rapidly. Most frequently the pistons will heat-up and expand well ahead of the cylinder bores. The chances of clearance-related scuffing and seizure are thereby increased proportionally.”

Translation? Something might break.

AMSOIL Director of Facilities and Maintenance, Rollie Everson, agrees. “I like to get them [engines] warm before putting any type of stress on the mechanical components. This makes sure components expand at a gradual rate when they are cold.”

2) Ensure the oil circulates properly

Another reason to warm up your bike is to circulate the oil. Here again John Skuzinski has some good insight. “Cold oils inhibit pumpability and flowability, making it more prone to thin-film and hydrodynamic-wedge breakdown. Under extreme cold-oil conditions, it is possible that the oil won’t be able to flow into the oil pump, leading to bearing and journal damage and wear.”

Translation? Again, something might break, this time due to lack of oil.

Of course, a good solution to poor cold-flow is to use a high-quality synthetic that flows quickly to engine parts despite cold temperatures. AMSOIL laboratory chemist Dale Beck explains:

“The highest chance of wear should be under the initial startup when the oil has yet to be circulated to all the components in the upper end. AMSOIL motorcycle oils have very good pumpability at cold tempatures, definitely colder than I enjoy riding the bike at, so I don’t worry much about the oil not being circulated enough. Our oils also have very good protection for cam wear, relating to initial startup, so unless you are redlining the engine after startup there shouldn’t be any worries about other engine parts.”

How long should you warm the engine?

About one minute is plenty of time to allow the piston and other parts to gradually expand and ensure good oil circulation to the upper end. Most riders start the engine and spend a minute or two putting on their helmet and preparing to ride. Once they’re ready, so is the bike.

“I warm mine up so I know everything is running well. I usually do this while I put on my helmet and make final adjustments before departing on a ride.” – Patricia Stoll, AMSOIL Trade Show Manager

“I usually let it warm up while making my last adjustments (ear plugs, gloves, glasses, etc.). This takes about a minute or two.” – Jim Swanson, AMSOIL Trade Show Representative

“I would guess that mine only warms up for around a minute. I usually start it just before putting on my helmet and gloves. In my opinion, anything more than a few minutes is a waste of fuel and can lead to deposit formation on the spark plugs and exhaust.” – Dale Beck

To wrap it up, warm up your bike for at least a minute before heading out. Just use the time to buckle your helmet, slip your gloves on or finish other preparations. That way you’re not wasting time – and you’re likely saving your engine from wear.

Find out why our Co-President & CFO loves V-twins.

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