Isky Racing Cams On Why You Need Bushing Roller Lifters!
HOT ROD Drag Week engine builders have made the switch to the EZ Roll Bushing lifters and you should too!
Drag Week is, without a doubt, the most grueling and toughest test on roller lifters. Five straight days of mid-six second passes at 200 miles per hour followed by a couple of hundred miles in traffic is torture on the engines as a whole—but especially the valvetrain. For years, top drivers were breaking roller lifters, and it was the cause of poor runs or going home. A few years ago, Dave Schroeder and John Ens made the switch to EZ Roll Bushing lifters after years of failures. What they noticed right away was the lifter problems disappeared, the lash never changed and the valve springs lasted longer.
They went on to become the 2017 Drag Week winners with a nitrous engine and finished second last year. Their Reher-Morrison 872 ci also won the 2018 Masters of Motors Best Nitrous Engine award.
Drag Week is one thing—but what about performance? Top engine builders have been running the EZ Roll Bushing lifters for well over a decade. From Jim Oddy setting Pro Mod records and winning championships with the lifters before anyone knew they were out there to very early adopters like Pro Stock engine builder Steve Schmidt, many have become believers over the years. Dave Adkins recently set the LSX World Record in the 1/8-mile at 3.75 seconds and 199.7 mph using a Baker Engineering twin turbo LS Camaro with the EZ Roll Helix, Isky’s latest version which features two grooves on the inside of the bushing that allow extra oil flow at low and high rpm.
Isky has supplied several of the Street Outlaws No Prep Kings racers with its new EZHelix Bushing lifters. As Mike Murillo, Scott Taylor and Bobby Ducote are forced to step up their programs to keep pace, failures started coming along with the extra boost and higher pressures. They have each made the switch and are running up front again.
Why a bushing lifter? Isky visited Richard Childress to see the first running Spintron and the information it could provide and immediately bought the third Spintron off the line to use while testing new spring designs made by partner PSI Springs. (A little-known fact, Isky was the first customer and partner with PSI). During early Spintron testing of the new Gold Stripe Springs, testers kept losing needle-bearing lifters as they pushed the limit higher and higher. With the Spintron and laser system, however, they were able to really see the amount of distortion the roller needle bearing goes through. They were also able to see the difference in the designed cam motion and the true valve motion at high rpm’s and loads. Isky reps were shocked to see how much the lifter distorted going up the ramp, as well as the rebound effect as the valve closed. This was translating bad harmonics throughout the whole system, limiting performance and breaking parts.
Isky found that as testers pushed the combinations, the needles actually spread apart from each other so much that the main pin would contact the outer race wheel, breaking it and sending needles through the engines. The frustration of losing needle bearing after needle bearing is what led Isky to start work on a bushing lifter, which had been tried many times before but not quite right.
When Isky got the right material mix, testers found a lifter that lasted three to four times longer than any needle bearing lifters tested. The benefits were undeniable, you could now have a lifter that lasted longer, did not distort under the most aggressive cam profiles and pressures, dampened valvetrain harmonics and actually gained horsepower!
Now for the how. The real key is in the material, and Isky is actually on its fifth version of bushing material. Not satisfied with the EZMax version, they kept testing and says it would be hard to ever top its latest EZHelix version, which features new material and double helix grooving. A bushing lifter works off of the simple concept that there is no metal-to-metal contact, and the outer wheel or bushing rotates around the pin on a bed of oil.
We all understand how strong hydraulic pressure can be and if you simply get the oil to stay in place the roller would rotate without wear and low friction. Sounds simple until you add in rotating mass, pressures and heat. What happened in earlier attempts is that the pressures would squish out the oil and the wheel would contact the pin. After testing, Isky finally found a material that would hold the oil on its surface under high pressures. Its latest version is able to survive long periods of sustained rpm at 1500 lbs. open pressure with over 70 psi boost. Every EZ Roll Bushing lifter is the only bushing lifters that allow you to run engine oil restrictors.
Let’s cover a few misconceptions about bushing roller lifters. One question asked all the time is about hp loss due to friction. After explaining the how earlier, this idea of hp loss runs contrary to the goal and design of the bushing lifter. A new set of Isky EZ Roll lifters are hard to spin because they come pre-lubed with a special, thick break-in oil. As mentioned in the installation instructions, however, once the break-in oil is heated and run in the first time, there is considerably less friction.
If you take a look at the needle roller bearing, you have the needles not only rotating against the inner axel but at the same time the outer wheel. This not only creates friction and heat, it promotes wear from second one of running time. In a bushing roller there is zero metal-to-metal contact, the bed of oil prevents the contact and friction of any metal-to-metal surface. The constant flush of oil through the system also helps to cool it. With the needle bearing, the load is spread only over the three or four needles in contact with the wheel and axle at any one time. With the bushing, the load is spread out over the full contact of the wheel oil barrier and provides about 350% more load capability.
The EZMax and EZHelix Solid Roller Bushing are available as an option on all of Isky’s Tie-Bar Roller Lifters and come standard in all of its Keyway Roller Lifters. Isky also offers the EZHydro Roller Bushing in all its Hydraulic Roller Lifters for applications from the LS, Ford, Gen III Chrysler Hemi, Retro Fit Engines and even the Harley Davidson Twin Cam and Evolution engines.