How to Install an Oil Cooler on a Harley-Davidson Twin Cam

In this article, we're going to talk about a very important topic in American Big Twin engines: air cooling.

Aircooled Powertrain
Indeed, the engine of our Milwaukee engine dissipates the heat from its operation directly into the surrounding air (unless your bike is a V-Rod). As we all know, when it's hot, we appreciate having a nearby fan or a stream of air to cool us down a bit. Well, this is exactly what our engine needs: airflow.
The only effective way to maintain an adequate temperature in this type of engine is by moving it. This promotes air circulation between the fins and engine components, thus promoting adequate heat transfer. This means that in slow traffic, at stoplights, etc., the engine lacks sufficient cooling capacity, reaching critical temperatures that we must avoid.

The radiator
Another point to keep in mind, especially if you live or drive in countries with hot summers, is that summer temperatures can put any air-cooled vehicle to the test, even when moving, especially those that are boosted or heavily loaded.
One way to improve cooling is to install an oil cooler . By slightly cooling the oil flowing through the engine, we can help lower its temperature by a few degrees. In our tests, this lowers the temperature by between 10 and 12 degrees Celsius, which isn't bad at all.
We're going to install a Harley-Davidson oil cooler kit, which comes with all the necessary components so you can have everything ready in just an hour and a half.

We start with the adapter

To start, we remove the oil filter and clean everything well, and we look at the nut that holds the filter.

Next, using a socket wrench, we unscrew this piece.

We then proceed to place the adapter provided in the kit, which is installed with a gasket and a new thread.

We place it where the oil filter used to be and tighten it to the torque recommended in the instructions.

We continue with the radiator
Now we'll place the radiator in its place, between the chassis tubes, using the plastic clamps provided in the kit.

We're now ready to install the oil hoses or lines. These lines come pre-formed and marked with top and bottom, so we need to follow the instructions carefully to make sure everything is connected correctly.

Once we have positioned them, we secure them with the clamps provided in the kit.

Final checks
Well, now we have our brand new spokes, we install a new oil filter and then we start the bike.

We need to check that the oil pressure indicator light is off and that there are no leaks in the system. Finally, we'll warm the engine to operating temperature and check the oil level following the manufacturer's workshop manual, adding oil until the correct level is reached (generally, we'll need about 150cc more after installing the radiator).

Frank Burguera

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