Don't Let Oil Temps Stop The Fiesta! Mishimoto Oil Cooler R&D, Part 1: Plans and Initial Fabrication

Don't Let Oil Temps Stop The Fiesta! Mishimoto Oil Cooler R&D, Part 1: Plans and Initial Fabrication

Interested in purchasing this awesome oil cooler system? Check out our product page for more details!

Mishimoto Ford Fiesta ST Oil Cooler Kit

We've been posting on the Fiesta ST forums for some time now, talking about our upcoming products (Fiesta ST aluminum radiator and Fiesta ST oil catch can system), reading through build threads, and requesting recommendations from the community. One of the most requested components is a direct-fit Fiesta oil cooler solution. Luckily for ST enthusiasts, we are extremely familiar with this product, as validated by the 21 direct-fit kits our engineering team has designed and tested thus far.

ST Plans

So what do we have planned for our Fiesta ST oil cooler kit? We had a few requests for a radiator/oil cooler combination kit with bracket mounts fixed to the radiator. While this is a good idea, it has a few flaws. First, the AC condenser sits directly in front of the radiator. Designing a mount to go around the condenser would be quite a challenge and would also create an "interesting" install. Our primary reason for avoiding this combination package is that we do not want our customers to feel forced to purchase a combo package. If customers want just a Ford Fiesta oil cooler, we want that to be an option. Because of this, we will be designing this kit to function with both the stock radiator as well as our thicker aluminum counterpart.

As with most of our other oil cooler kits, this will be completely direct-fit and will include every item necessary for install, down to the last nut and bolt. We will also provide a video install guide that will highlight the process from start to finish.

One thing that we like to do with our kits is provide an in-depth look at our testing data. Although most of this data is collected during street driving, we can capture efficiency information that can be used to estimate track benefits. We will be using our AEM data logging software and temperature sensors to capture and display our results with both the stock and Mishimoto Fiesta oil cooler.

Stock Oil Cooler

The stock Fiesta oil cooler is a liquid-to-liquid heat exchanger that doubles as both an oil warmer and an oil cooler. It is a common component that helps reduce wear during oil warmup and then works with engine coolant to help keep temperatures in check. Check out a couple shots of the stock Fiesta ST oil cooler!

Stock Ford Fiesta oil cooler
Stock Ford Fiesta oil cooler

Stock Ford Fiesta oil cooler
Stock Ford Fiesta oil cooler

As we've found out through the forums and enthusiast's groups, this Ford Fiesta oil cooler is fantastic for heating the oil, but it falls short in cooling performance. Many drivers are seeing oil temperatures that are quite high during aggressive street driving. This is a big problem for those who purchased a performance vehicle and expect to drive it like so.

In the images above you will notice the tight clearance in the area of the oil filter and Fiesta oil cooler assembly. Because of this, we will eliminate the stock oil cooler, and in its place we will mount our oil cooler sandwich plate. We will offer both a thermostatic and non-thermostatic kit. The thermostatic option will restrict oil flow to the heat exchanger until proper temperatures are reached. This is an ideal setup for a street-driven vehicle and ensures that oil is warmed properly.

Bracket Fabrication

The start of this project begins with fabricating brackets to mount our heat exchanger. We want a location with the most possible airflow to provide efficient heat exchange. The obvious choice is the front grille. To place our cooler in a position compatible with taller aftermarket front-mount intercooler kits (FMIC) kits, we will mount this cooler in the upper portion of the grille.

First, the bumper is removed to see what we are working with!

Fiesta ST with bumper removed
Fiesta ST with bumper removed

Fiesta ST with bumper removed
Fiesta ST with bumper removed

Fiesta ST with bumper removed
Fiesta ST with bumper removed

The center portion of the upper grille seems appropriate for mounting our 19-row cooler. We begin by taking measurements from our planned mounting points and drawing brackets in Solidworks. Once in 3D, we can print out templates and construct our Ford Fiesta oil cooler brackets from steel.

Cutting bracket templates for Mishimoto Fiesta ST oil cooler
Cutting bracket templates for Mishimoto Fiesta ST oil cooler

After a few quick cuts on the band saw, our initial bracket shapes were complete. We then bent them at the proper angles to clear the crash beam and other front-end components.

Fabricated Fiesta oil cooler brackets
Fabricated Fiesta oil cooler brackets

We then fit these into position on the vehicle!

Fabricated Fiesta oil cooler brackets installed
Fabricated Fiesta oil cooler brackets installed

Fabricated Fiesta oil cooler brackets installed
Fabricated Fiesta oil cooler brackets installed

Some slight tweaks were made and soon we had the oil cooler mounted on our Fiesta!

Fabricated Fiesta ST oil cooler brackets installed
Fabricated Fiesta ST oil cooler brackets installed

Fabricated Fiesta ST oil cooler brackets installed
Fabricated Fiesta ST oil cooler brackets installed

We then added a third bracket for some additional cooler support. We typically use three mounting points for optimal rigidity, which eliminates the impact of airflow or high-g cornering on bracket flex.

Fabricated Ford Fiesta ST oil cooler brackets installed
Fabricated Ford Fiesta ST oil cooler brackets installed

Coming Up!

Next up on the list of tasks is to determine if this kit functions as well as it looks. We will be strapping our testing sensors and equipment to this hot hatch and hitting the highway to evaluate temperature on both the stock setup as well as with the Mishimoto Ford Fiesta oil cooler installed.

Check back next time for a look at the testing process as well as the results!

Thanks for reading!

-John

Interested in purchasing this awesome oil cooler system? Check out our product page for more details!

Mishimoto Ford Fiesta ST Oil Cooler Kit