How long it takes a motorcycle engine to cool down


The time it takes for a motorcycle engine to cool down depends on how hot the engine is and what the outside temperature is. Usually, it would take about 2 hours or more for an engine at normal operating temperatures to cool down enough to be able to open it up without burning yourself.

Overview

In this short article, we look at how long it takes a motorcycle engine to cool down and if there is anything you can do to speed up the cooling process.

We will discuss the following:

  • The rate at which an engine loses heat
  • How to speed up the cooling process

The rate at which an engine loses heat

Graph showing engine temperature over time

You could reckon on about two to three hours for the engine to cool down.

As you can see in the image above, the engine temperature doesn’t decrease at the same rate over time. This is because the rate at which heat is transferred depends on the difference between the current temperature and the outside temperature.

This just means that the closer the temperature of the engine is to the temperature of its surroundings, the slower it will cool down. But don’t think that a hotter engine will cool down faster.

Nope, that’s unfortunately not how it works. You’re just starting at a different point on the graph and it might seem like the temperature is dropping faster at first but the rate will change as the engine gets cooler.

How to speed up the cooling process

There is one way that you can speed up the cooling process when the motorcycle is standing still in your garage. You can put a normal household fan down in front of the bike pointing onto the engine. This might not make a big difference but it does help.

Why does this work? Well, the heat from the engine is transferred to the surrounding air which is how any engine cools down (some might first transfer it to liquids that run through the engine but its the same principle).

When the bike is standing still and there is no wind, the hot air just hangs around the engine and slowly moves upward (because hot air rises). This makes the difference in engine temperature and outside temperature less so the rate of cooling is lower.

So you want to get that hot air around the engine away faster so its always in contact with cool air. And this is basically hot air-cooled engines work. Water-cooled engines would first take the engine heat through water into a radiator and then the air would cool the radiator.

But even though water can cool off an engine pretty good as it absorbs the heat when it turns into a gas, you shouldn’t do this as the metals could cool down unevenly and cause it to crack. What you can do is to take a spray bottle with water and just spray some in front of the fan every now and then.

Final words

I don’t normally worry too much about how fast the engine cools unless I have to open her up. But with the naked bike, I always had to wait a bit before putting the cover over so the engine doesn’t come into contact with the nylon cover. I hope all of this answers your question and maybe some others as well.

I always try to keep my articles interesting and informative. And I’m always thankful when they are shared on social media platforms or Pinterest.

Two Motion

I don’t see myself as an expert in every topic of motorcycling but my articles usually relate to new experiences that are relevant at the time of writing.

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