PARADOX HMMWV 6.2/6.5/6.5T COOLING UPGRADE KIT (patent pending) This is simply the best bang for the buck upgrade you can make to your truck, period! Must do before any performance or horsepower mods. All HMMWV HUMVEE trucks with GM Detroit Diesel V8 6.2/6.5/6.5T engines all share an inherent design flaw in their cooling circuit. Due to the packaging of the cooling system, coolant distribution is disproportionately fed to the front of the engine block and heads. The rearmost cylinders run significantly hotter due to this inadequacy, while the fronts are overcooled. Diesel engines run best in a tight band of temperature. In the earlier 6.2 engines these higher rear temperatures led to many of the well known failures in those engines which are nearly always in the rear two cylinders. The 6.5T engines have an all too common #7 & #8 cylinder failure rate. Later blocks increased block density and used better metallurgy, among other improvements, to reduce the catastrophic failures, but never addressed the cooling imbalance and the loss or performance from this.
Paradox developed our system using proven technology from our Motorsports background. The Motorsports industry has long known of the benefits to balancing the temperatures across V8 engines, especially when running at the cutting edge of detonation needed to make maximum power. While that may not be the goal of most Humvee owners, cooler running temperatures, better power and efficiency are. Further, the reduced heat from the rear of the engine is a welcome reprieve from hot cabin temperatures, too. On average, the mechanical fan cycles on 25%-50% less than stock with our kit installed. This is the most obvious advantage to our kit as this greatly reduces the loss of power, added noise and fuel burn! The Paradox system opens up the blocked off rear coolant area of these engines and allows for flow to the front of the coolant circuit. By opening this up we create coolant flow to the once dead area of the block. The added benefit is reduced air/steam pockets and constant coolant bleeding to the overflow tank. Countless hours of testing and tuning went into developing this kit with the proper flow for maximum benefit, as well as to assure proper match to the front of the block. Diesel engines need to operate in a narrow band of temperature to maintain optimum efficiency. Without our kit the front of the block is over-cooled and the rear under-cooled, leading to loss of power and efficiency. Our system is hand assembled in the USA with all USA made parts. In this latest kit, V3, we use Aerospace certified AN fittings, high temperature/pressure stainless steel braided hose with a soft outer layer to not cut into your soft metal parts. We fabricate a custom bolt on replacement for the rear coolant block off plates which includes new gaskets as well. Everything is a true bolt-on system. The complete kit is in BLACK. Should you desire to remove the system it is fully reversible as well. All systems come with a color step by step guide for installation. Buy with confidence with a full one year warranty against manufacturer defects and workmanship.
Fits ALL HMMWV trucks with 6.2, 6.5, 6.5T engines. Please select the correct of two available options at checkout. If you have the center mounted turbo you must select that kit.
NOTE!! THIS KIT WILL NOT FIT CUCVs, or street vehicles with 6.2ltr or 6.5ltr Turbo or Non-Turbo vehicles! Please return to the PRODUCTS page and look for your correct application!
Some pictures are of previous versions V1, V2 or different applications and are for reference only!
Add Ons: We can option your cooling kit with a few add ons if you desire. We can add the ability to flow coolant to an aftermarket water cooled turbocharger with our kit. Another option is to add a port for you to add an aftermarket coolant temperature gauge. Yet another option is to add an aftermarket fuel pre-heater system for cold climates or bio-diesel applications. These are all add ons we can option into our cooling upgrade kits now or in the future. Please contact us to set these up for you.