Sometimes boat owners think they can skimp out on replacing an outdated thermostat. While a thermostat is a small part of a marine engine, it is crucial for the engine’s overall health. Due to its importance, it’s critical not to discount the value of monitoring your thermostat and replacing it when needed to ensure your engine runs at its top performance.

Learn more about what marine engine thermostats do and how you can choose the right one for your Cummins 6BTA engine.

Thermostats for Marine Engines

A marine engine thermostat does more than monitor the engine’s temperature. It’s an essential component that regulates engine temperature and ensures the cooling system has enough pressure for heat transfer from cylinder walls and heads. The thermostat is located in the outboard’s cooling system and is a valve. Depending on the temperature, this valve will open or close to ensure the engine operates at the right temperature.

When the motor’s operating temperature needs to increase, the thermostat valve will close, stopping any cooling water from flowing through the outboard. If the operating temperature needs to be reduced, the thermostat will open, allowing the coolant to pass through the outboard and decrease the temperature.

A properly functioning thermostat will continually open and close at the needed times to keep the motor running at the best temperature. When a thermostat is in good condition, it stops the engine from overheating and prevents engine damage that could leave you stranded on the water. A working thermostat also minimizes fuel consumption and maximizes the engine’s power. 

To keep your engine’s thermostat running in optimal condition, you should examine it at regular maintenance intervals for sticking and corrosion. You also need to check the thermostat to see if it’s regulating the temperatures correctly. Keep in mind that operating an engine in muddy or salt water will require you to check the thermostat more regularly.

You might also want to note that high temperatures can damage thermostats. If your engine has overheated, it’s highly recommended to replace the thermostat. As a general practice, regularly check your engine temperature while also servicing the cooling system at recommended intervals to keep your engine running at peak efficiency.

The Difference Between 160F and 180F Thermostats

Many older Cummins marine engines, such as the B5.9 models, come standard with 180-degree Fahrenheit thermostats. This practice of providing a 180-degree thermostat is effective for some common applications that use Cummins engines for non-marine purposes. Non-marine engines don’t use a large amount of gallons per hour, and they rely on less horsepower compared to marine engine use. A 180-degree thermostat may be effective for other types of engines, but not a marine engine.

To illustrate why marine engines may need a 160-degree Fahrenheit thermostat, consider that you’ll produce a significant amount of horsepower when driving a boat. Additionally, you’ll use a large number of gallons per hour when operating a boat. The combination of the increased heat and the gallons used creates a sizable amount of heat.

For marine engines, their coolant systems must withstand with a great amount of heat to ensure the engine doesn’t overheat. A marine engine is usually placed in an engine room where there isn’t any outside air to cool it down. Due to the lack of air cooling, a marine engine must rely on its coolant system much more.

As marine engines have become much stronger, newer Cummins engines have switched to 160-degree thermostats as the standard. These 160-degree thermostats can catch overheats earlier. Since marine engines rely on their coolant to keep from overheating, these 160-degree thermostats can help a marine engine run cooler and do a better job of monitoring how hot the engine is getting.

With engines putting out more horsepower and generating more heat, the need for a thermostat that can catch overheating early on has become much more important. A 180-degree thermostat will send an alert signaling the engine is reaching a dangerous temperature at a higher temperature than a 160-degree thermostat will. You can also differentiate thermostats by thinking of 180-degree models as designed for older marine engines that aren’t as powerful as newer versions that release more heat. 

The Right Thermostat for Cummins Marine Engines to Avoid Overheating

Cummins engines do not tolerate overheating very well. Overheating can significantly reduce the engine’s life span, leaving you to deal with the costs of replacing it and possibly losing power while on the water. It can be difficult to catch a temperature rise for most engines, which can end up overheating and cooking the engine, leaving it inoperable. High temperatures can also harm key parts like the exhaust manifold.

It’s crucial to prevent your engine from being exposed to high temperatures for a lengthy period. As such, a 160-degree thermostat is usually the better choice for Cummins engines. It gives boaters a larger safety margin to catch overheating conditions and respond to them quickly.

Most engines come with a redundant alarm system that alerts boaters when the motor gets too hot. One of the downsides of using a 180-degree Fahrenheit thermostat is that it sets off an alarm at a higher degree point. At times, this alarm can go off too late, allowing the engine temperature to stay at a dangerously high level for a long time.

This extended period of the engine operating at a higher temperature can cause irreconcilable damage to an engine. These alarms can be too little, too late, especially if the boat owner doesn’t immediately hear it.

A major advantage of using a 160-degree thermostat for your Cummins Marine 6BTA engine is that it allows you to set your alarm system to trigger at a lower temperature. This lower-temperature alarm means you can catch an overheating engine before it reaches a point where it can’t be fixed.

Invest in Cummins 6BTA Replacement Parts From Hubei July

Whether you’re looking to repair a damaged part of your engine or want to have replacement parts available in case of an emergency, Hubei July has your back. We offer our customers various Cummins marine parts, such as components for the Cummins 6BTA engine.

Browse our selection of Cummins 6BTA parts to find high-quality components for your engine. If you have any questions about our products, please feel free to contact our friendly customer service team.