Mishimoto prototype Ford Fiesta radiator

Keeping The Party Cool! Mishimoto’s Ford Fiesta ST Radiator R&D, Part 2: First Prototype Evaluation and Installation

Interested in picking up our Fiesta ST aluminum radiator? Check out our discounted pre-sale linked below.

Mishimoto 2014+ Ford Fiesta ST Aluminum Radiator Pre-Sale!

We left you with some pretty cool 3D models last time. We are back with something even better … our first prototype has arrived!

Prototype Radiator

I know you guys are excited to see this piece so I won’t extend the wait any longer. Check out some shots of our first prototype!

First, a look at the front of the radiator.

Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator

A look at the back (engine-facing) side of our prototype!

Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator

We’ve emulated the stock fan shroud mounts as well as the inlet and outlet hose locations. The upper and lower radiator mounting pegs are also positioned just like the stock radiator.

Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator

I am sure you are looking at these images and thinking, “The thickness of that radiator is absolutely astonishing.” Well, you’re right; it is a massive core. Here is a closer look from the side.

Mishimoto prototype Ford Fiesta radiator
Mishimoto prototype Ford Fiesta radiator

Just how thick is it?

Mishimoto prototype Ford Fiesta radiator thickness
Mishimoto prototype Ford Fiesta radiator thickness

Our first prototype measures 2.25”. Keep in mind this prototype is based on a variety of 3D models of the stock vehicle. Our sizing is an educated guess and may need to be scaled down slightly for fitment purposes. We shall see with the test fit!

So how does this compare with the stock Fiesta ST radiator in terms of size and volume?

First Prototype Spec Comparison

Mishimoto prototype Ford Fiesta ST radiator (top) and stock Fiesta ST radiator (bottom)
Mishimoto prototype Ford Fiesta ST radiator (top) and stock Fiesta ST radiator (bottom)

The chart below provides a nice comparison of the basic specs of both the stock radiator and the first prototype we designed.

Chart

So, our first prototype provides over twice the volume of the stock radiator. The puny stock unit measures just one inch in overall thickness.

The fin height determines how many rows of fins we can include, as well as how tightly they are packed into the core. A smaller height between fins will improve heat transfer, although it will restrict airflow through the core. It is give and take here. The stock fin height is 6mm, while our first prototype unit is 6.5mm, slightly larger.

Another interesting feature to note is the little brass component in the upper radiator tank. This piece is a bit experimental and functions to bleed air easily from the cooling system. The spring-loaded bleeder must be depressed to relieve pressure and air from the coolant system. Typical setups utilize a screw at a high point in the system. We will be testing the functionality of this piece and potentially incorporating it into our final design.

Check out a closeup of the core our engineering team designed for this radiator!

Mishimoto prototype Ford Fiesta ST radiator core showing relative height between fins
Mishimoto prototype Ford Fiesta ST radiator core showing relative height between fins
Mishimoto prototype Ford Fiesta ST radiator core
Mishimoto prototype Ford Fiesta ST radiator core

The tightly packed fins are key for improving heat transfer and will help provide greater surface area for more heat-transfer contact points.

One more comparison shot of both radiators!

Mishimoto prototype radiator (left) and stock radiator (right)
Mishimoto prototype radiator (left) and stock radiator (right)

As you can see from the chart above and the images, the Mishimoto radiator dwarfs the stock unit.

Prototype Test Fit

With our prototype in hand and our Fiesta on the lift, it was time to test fit our first prototype and see where changes would be needed.

First, the stock radiator was removed.

Removing stock Ford Fiesta ST radiator
Removing stock Ford Fiesta ST radiator
Removing stock Ford Fiesta ST radiator
Removing stock Ford Fiesta ST radiator

Yes, you are seeing things correctly. Most of the front end of the Fiesta must come apart and be separated to access the radiator. Tight packaging is great for weight reduction, center of gravity, handling, and emissions, but it certainly makes maintenance and repair work a challenge.

We had the stock radiator out as well as the stock fan shroud. We fit this piece up first to check out mounts for appropriate fitment.

Mishimoto prototype radiator mated to stock fan shroud
Mishimoto prototype radiator mated to stock fan shroud

Next we fit our prototype in place, but we quickly found that we had been a bit optimistic with the size of our core. As a result, we ran into some fitment issues that kept us from fitting this unit in place. The thickness of the core pushes the fan shroud a bit too close to the engine, causing some clearance concerns. But … this is why they call it R&D right?

No worries here, a few tweaks and a slight decrease in core size should give us an aluminum radiator that features greater fluid capacity and fits perfectly! On top of this, we will be modifying our fin height to 5.5mm in order to pack a few more rows of cooling tubes and to promote greater heat transfer with a denser core.

Check back next time for a look at our next prototype unit and test fit!

Thanks for reading!

-John

Interested in picking up our Fiesta ST aluminum radiator? Check out our discounted pre-sale linked below.

Mishimoto 2014+ Ford Fiesta ST Aluminum Radiator Pre-Sale!

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