Forged Pistons at the Heart of Next-Level UTV Performance | JE Pistons
UTVs have ushered in a new era and means for people to enjoy the outdoors with friends and family, create competitive racing series and classes, get work done on the farm, and can even be optimized for hunting. Whether you’re a current UTV owner looking to build some competitive power or you’re considering saving a little money and buying a used one, engine performance and internal components are at the heart of a UTV’s success. At JE Pistons, we’ve developed pistons for numerous UTV models with the simple goal of ensuring long-lasting performance and seasons of trouble-free operation.
Competitive competition and weekend recreation with UTVs has increased drastically over the last decade, making an permanent impact on the powersports industry. Photo: DP4 Racing
Having options is one simple, yet very important factor in making sure fellow UTV owners and enthusiasts have their needs covered. JE Pistons’ UTV pistons are offered in stock, low, and high compression ratio variants in many cases, and from OE to increased bore sizes. This combination of options covers two main engine rebuild scenarios: building the engine for more power and improved performance and rebuilding the engine to regain OEM performance and reliability.
Whether you’re rebuilding your work horse for reliability or aiming for more power and more fun, forged pistons tailored to your build are a critical component at the heart of your UTV’s powerplant.
More Power, More Fun, More Victory
Let’s take a look at scenario one, building for more power and improved performance. This type of engine building goal is typically for those who are competing in their UTVs or are recreational users who just want to have more fun. This is where different compression ratios and bore sizes play a big role. For models such as the Polaris RZR and Yamaha YXZ 1000, pistons are available in various compression ratios, from low compression for turning up the boost to high compression for naturally aspirated power. Overbore sizes available on the shelf for Polaris RZR 800 and 900 models as well as Yamaha Rhino and Kawasaki Teryx models make for seemingly endless combinations of build options.
The Polaris RZR 800 is the model that arguably started the now-popular trend of recreational use of UTVs. Because of this, there is still quite a few of these in people’s garages. Even though there may be hundreds of hours on them, freshening up the top end with new pistons and rings is a key factor in affordably regaining that have-fun performance without purchasing a completely new unit. Rebuild to OEM displacement and compression, bore it out, strap a turbo on it, or bump up the compression, JE has pistons for whatever your poison may be on the shelf.
Working in conjunction with the OEM design and holding up to added power, JE’s RZR 800 pistons are designed on a full-round forging, providing the stability and strength needed for this application.
Polaris RZR 800 models are still plenty viable among the newer, much more expensive models. Plus. with several options to turn up the boost, increase displacement, and increase compression, more power can make it feel like a whole new machine. The piston above with the deeper dish has a lower compression ratio designed for more boost. Notice the ring lands are also thicker to withstand increased chamber pressure.
When the RZR models graduated to a slightly more robust 900 with a powerplant boasting an additional 100ccs, people began to challenge these vehicles even more. Bigger obstacles, more modifications, and organized competition all contributed to the desire and need for more performance. Because no two engine builds are the same, JE has 23 different piston part numbers for the 2011-2014 RZR 900 models. Bore it out 2, 3, or 5mm over and turn up the boost or increase the compression.
The pistons for this model are designed and manufactured using a Forged Side Relief forging, meaning only the necessary amount of skirt material is retained, allowing for a lighter and quicker-revving part. To retain strength, these pistons utilize a boxed and strutted design.
Seemingly endless combinations of bore size and compression ratio for RZR 900 engines can help fine tune each build for each driver’s unique needs. Forged Side Relief (FSR) forging design allows JE to reduce weight and operating friction, while maintaining strength through boxed and strutted designs.
Of course, we didn’t forget about the industry standard, the RZR 1000. The same performance desire story most definitely does not end with the 1000 model, so you’ll find pistons ranging from 9.5:1 up to 12.0:1, ready to take whatever abuse you can throw at them.
New Kids on the Block
Some relatively newer model UTVs that have emerged to compete with the Polaris staples are the machines from Can Am, Honda, Kawasaki and Yamaha. Can Am’s earlier Maverick 1000 X RS and late X3 Turbo have proven that the evolution of UTV performance and capabilities are not slowing. On new OE turbo-equipped models such as the X3 Turbo, tuning has quickly become a popular way to achieve more power by turning up that boost knob. But, if you really want to go full rock star and turn it up past max and rip the knob off, equipping your machine with a set of forged slugs made to handle that kind of power would be a smart move. Beefing up your machine’s powerplant in the beginning is much more affordable and less hassle than rebuilding the entire engine when a failure happens.
This is where JE’s Ultra Series pistons come into play. Now available for many late model UTVs, Ultra Series are the powersports industry’s strongest pistons yet. Using JE’s proprietary Aligned Grain Flow technology to create a forging with next-level strength, Ultra Series pistons are built to withstand the demands of high-horsepower, power-adder builds. Finished with features like thermal barrier crown coating, lateral gas ports, skirt coating and more, Ultra Series are the ultimate pistons for UTV performance.
Another new UTV model that has made waves is the YXZ 1000 from Yamaha. With a high-revving, street bike-sounding triple cylinder engine and an actual gearbox, this racey little car has left many drivers with smiles on their faces. “Maybe I should put a turbo on it,” you might think, or, “I wonder what it would drive like with more compression and race fuel.” Well, the answers to those questions posed by the little horsepower monster on your shoulder are just an engine build away.
JE Piston’s YXZ 1000 pistons are made with a Forged Side Relief and boxed and strutted design, adding assurance in strength and ensuring no comprises will need to be made in the ‘screaming RPMs’ department. A 9.5:1 compression option is ready to see the red zone on your boost meter, and 11.5:1, 12.5:1, and 13.5:1 CRs maximize naturally aspirated performance.
Performance in Design
Designing pistons for these lower or increased compression ratios is not just a matter of lowering or raising the piston dome. These designs begin with a completely digitized laser scan and precise measurements of the specific model’s head and combustion chambers assembled with their corresponding valves. With this data, JE’s in-house engineers are able to create dome designs that not only achieve a goal compression ratio but retain the best possible fuel/air travel efficiency and most consistent heat dispersion. Finite element analysis (FEA) allows the engineers to virtually identify what areas of the part will be most susceptible to stress and heat and take that data into account accordingly.
Once these designs are manufactured, they are measured using coordinate measuring machines (CMMs) to ensure the parts precisely reflect their design and are up to JE Pistons’ quality standards.
The boxed and strutted design of JE’s FSR forgings maintain optimal strength while simultaneously reducing weight. Weight reduction is taken seriously, with additional machining operations to create windows and remove material where it won’t compromise the part’s integrity.
More of the Latest and Greatest in UTVs
Other major motorcycle manufacturers have joined the UTV game, including Honda with their Talon 1000 models and Kawasaki with an expansion of their Teryx line, the sport/performance focused KRX 1000.
Despite their recent release, JE has already performed their due process and developed complete lines of pistons for these new machines. Pistons are available now for these platforms in various levels of compression ratios, and Ultra Series are available for the KRX.
Reliability for Utility
What about the machines that are actually used for what the name implies, utility? Whether it’s handling work on a ranch or hauling your game back from a hunting trip, all these users have one thing in common: they want their UTVs to start and run strong each and every time. With plenty of other work to do, the last thing you need to worry about is having to work on the tools you need to get your work done, right?
After hundreds of hours of putting in work, sometimes all these machines need is a freshened up top end to get back to like-new performance. A set of new pistons and rings along with some love for the cylinders can not only bring back power you forgot was ever there, but also provide even more reliability than the OEM parts. The 2618 alloy JE uses to forge all their powersports pistons has a greatly increased tensile strength for even more durability.
What’s in The Box?
All UTV piston kits from JE are supplied with the necessary quantity of pistons along with their corresponding ring packs, wrist pins, and wire locks. JE puts a great deal of emphasis on the quality of their piston components in material, design, and performance. Wrist pin material and dimensions are carefully selected to provide plenty of strength with what the pistons were designed for. Ring material and shape are also critical factors considered with each piston part number. After all, a piston can only be as good as its components.
Each JE UTV piston kit comes complete with all required components, including high-quality rings, wrist pins, circlips, and the pistons, of course.
Whether you’re piloting your UTV to the checkered flag, the end of a hard day’s work, or a weekend well-spent, JE Pistons has the components to usher in performance and reliability. Should you have any questions on what parts are best for your rebuild, give the experts at JE a call or shoot them an email, they’re always happy to help!