Separating the oil from the chaff
Jim Weaver, general manager of the Spinner II product division of T.F. Hudgins, agrees. Spinner II is a cleanable, reusable centrifugal bypass filter that uses the engine’s oil pressure to spin an internal turbine at roughly 6,000 rpm, creating enough gravitational force to fling particles against the filter’s interior wall.
“The product differs from those using a barrier to screen off foreign matter because it’s not limited in the size of particles it will remove,” Weaver says. “We can actually take out material as small as 0.1 micron.”
Weaver says centrifuge-filtering technology has been around for about 50 years. It is first-fit equipment on 40 brands of engines around the world, including Mack and the industrial models of Caterpillar and Cummins. Spinner II is available through all truck manufacturers’ option books.
“Our product has an advantage over some of the others because it’s reusable,” Weaver says. “Customers never need to replace the filter, just a couple of O-rings. It is also very reliable. There isn’t a heck of a lot that can go wrong with it.”
In March, Fleetguard started competing with Hudgins for centrifugal customers when it introduced its Centriguard system. John Clevenger, a Fleetguard product group manager, says the company didn’t go after this business earlier because there were less expensive ways to achieve the same level of filtration. He says next year’s engines raise the ante.
“We believe multistage filters will be required,” he says. Centriguard provides that with full-flow, bypass and centrifugal areas, all wrapped inside the same can.
Clevenger says aftermarket bypass filters might clean oil well, but many of them don’t meet the minimum flow-rate standards set by engine makers. “Cummins and Detroit Diesel both say [a bypass filter] ought to average 10 percent of the full-flow filter’s volume, which is somewhere between 20 and 30 gallons per minute,” he says. “That means a bypass should handle 2 to 3 gallons in the same time. There are products on the market [whose makers] claim they can filter down to .25 microns. Yet, their flow rates are .05 to .10 gallons per minute. Cummins considers a filter plugged when it’s flowing .03 gpm.”
Furthermore, particles smaller than 2 microns can’t be accurately measured, so it’s hard to understand how some manufacturers can promise to clean below that level. “Technically, every filter catches some sub-micron debris,” Clevenger says.
John Guzek, owner of Energy Enterprises in Green Bay, Wis., has been in the bypass filter business for about 20 years. He markets a technology that was developed to maintain the oil quality of nuclear powered submarines for many months, despite their constant use.
“Submarines can’t dump fluids during a run,” he says, “so they needed a system to keep oil clean for a long time.”
Guzek says his first task in meetings with potential customers is to educate them about the product and its potential. “It is not immediately obvious what this can do for an engine,” he says, “and if you simply follow a manufacturer’s recommendations and believe that’s the best you can get, then you’re kind of locked into a box. This is more out of the box thinking.”
He describes the product as a “depth filter,” a sort of sponge or maze that oil must pass through while circulating. He says the design sets it apart from cartridge filters, “which are more like screen doors: particles either get through or they don’t.” After a few months of use, he says, his product’s performance actually improves because its cellulous media pores become narrower, making it more difficult for oil to penetrate. This restricts more contaminants and, equally important, absorbs more water.