First introduced in 2008, Ford’s 6.4-liter Power Stroke engine has become a front runner in the performance diesel market, able to make more than 600 rear wheel horsepower with nothing more than simple bolt-on upgrades. The 6.4 performs strongly in stock-class dyno competitions and holds its own drag strips and sled pull tracks across the country, all while still keeping its good streetablilty and impressive towing potential.
But like anything else, there are bound to be weak links in the system. As owners started putting more and more miles on their 6.4L trucks, many returned to their Ford dealers complaining of high coolant temperatures, leaking radiators and coolant hoses, and degas bottle problems. While Ford has issued multiple revisions to alleviate some of these issues, the aftermarket has stepped in to ensure the cooling issues can be resolved once and for all.
Mishimoto has been a leader in performance cooling products for cars and bikes since 2003, and they have recently jumped into the light duty diesel truck market with product lines for the Dodge Cummins, GM Duramax, and Ford Power Stroke engines. As automotive enthusiasts themselves, they could see the need for a superior Power Stroke radiator with improved durability and efficiency. Through countless hours of engineering and testing, Mishimito has released an all-aluminum radiator upgrade to replace the failure-prone OEM plastic end tank unit. While developing the radiator development, the Mishimoto team also found a need to increase the efficiency of the factory intercooler, particularly in high-horsepower applications that push large amounts of air through the stock core.
The Mishimoto unit is a direct replacement unit that fits into the stock location with no modifications to the truck required. Custom machined hose ends accept the factory quick connect coolant hoses and all factory mounting locations are retained so that the stock transmission cooler and A/C condenser can be remounted easily.
Constructed from high-strength aircraft-grade aluminum and covered by a lifetime warranty, the Mishimoto radiator has a brazed aluminum core that offers superior durability and efficiency to help keep the big Power Stroke engine cool under harsh driving conditions. The larger TIG-welded aluminum core and end tanks also allow for a 1.25-gallon increase in capacity. With this increase in fluid capacity and a superior core design, customers can expect more consistent fluid temperatures and better heat dissipation, which should improve the engine’s performance and efficiency, especially while towing over long grades in the hot summer months.
With factory-installed compound turbos, a tuned 6.4L Power Stroke can move some serious air. At 40+ psi boost pressures, the charge air temperatures climb rapidly, which reduces air density. While the turbos may be moving more air, that hot air is less effective in the combustion chamber and equates to a less efficient burn and higher exhaust gas temperatures. To combat this, Mishimoto developed a performance intercooler for the 2008-2010 Ford that can be installed in less than 30 minutes, even by a notice mechanic. The larger intercooler uses heavy duty cast aluminum end tanks and a more efficient bar and plate core, and can drop intake air temperatures by more than 20 percent.
During in-house dyno testing, Mishimoto’s test vehicle showed charge air temperatures increasing from a constant cruise temperature of around 100 degrees to more than 140 degress at wide open throttle with the stock intercooler. With the larger Mishimoto unit installed, cruising temperature dropped by 6-8 degrees with maximum temps increasing to just over 110-degrees on a long pull. This 25+ degree drop in charge air temp can yield major improvements in the combustion chamber and equates to a 100+ degree drop in exhaust gas temperature. Engineered to provide substantial benefits on a stock truck, the cast end tanks can also support the higher boost levels found in highly modified trucks. Like their radiator, the intercooler is backed by a lifetime warranty and is offered in shiny bare aluminum or stealth black powder coat. Installation instructions and a step-by-step video are posted on the Mishimoto website.
Let’s follow along as a Mishimoto radiator and intercooler are installed on a 2008 Ford Super Duty. Mishimito rates this installation at a three-out-of-five, as the cooling system will have to be drained and several parts need to be removed to gain access to the radiator (and since the intercooler must be removed as part of the process, this is a great time to upgrade it as well). The complete project should take about four hours, not including the time required to update your factory coolant hoses, thermostats and degas bottle (updates had already been carried out on our 2008 model installation truck). Mishimoto has full step-by-step videos on their website to help owners decide if the job is within their capabilities. DW
After installation of both the performance radiator and intercooler, our test truck owner reported the constant coolant leak problem had been resolved and his coolant temperatures now peak 5-6 degrees cooler than the stock while towing over steep grades, and that those temperatures fall back down to the normal operating range much quicker. With the new intercooler, EGT is reduced by nearly 125 degrees under wide-open throttle and almost 75 degrees while cruising. If you find your 6.4L Power Stroke is in need of some attention as the stock cooling system starts to show signs of weakness, Mishimoto has the products you need.