Gary Kellner
Gary Kellner of Kenworth explains how the new single-canister aftertreatment system works.
Peterbilt, Kenworth and other chassis makers are ditching dual-canister aftertreatment exhaust systems in favour of single-can modules.
The single-can aftertreatment system is the biggest change for 2017, Kenworth field service manager Gary Kellner said at a recent industry conference.
“This is what is going to affect you guys probably the most for installing bodies,” Kellner said during his presentation at the annual Canadian Transportation Equipment Association conference last fall in Vancouver.
Kellner acknowledged, though, that the single-canister solution “has been out for a couple of years” — a reference to Cummins Inc.’s launch of its trademarked Single Module system in 2015.
Paccar, Kenworth’s parent company, announced last March that its MX-13 and MX-11 engines would now use a single-canister system, which would reduce weight by 100 pounds and lengthen service intervals.
Peterbilt, also a Paccar company, is going to a single-canister exhaust for its 2017 models, said Greg Grabinksy, vocational sales manager for Peterbilt Canada. Basically that means combining in the SCR (selective catalytic reduction) and the DPF (diesel particulate filter).
Configuration depends on truck
“The big crucial issue on that is there used to be five different setups depending on the horsepower,” Grabinsky said. “So in some cases, on the medium duty application, we may actually get a little of frame-rail space savings. If you take a look at the Cummins X15 AHD, the big 560-plus horsepower engine, that whole canister is going to be about two inches longer than the current setup.”
The canisters have different configurations, depending on the truck, Kellner said. They include right-hand-under mounting for vocational trucks, horizontal under-frame mounting, a vertical/independent mounting, and a right-hand under-frame mounting for trucks with fairings.
The single canister not only saves on weight, it is more efficient and less likely to cause trouble. “But, depending on the engine you’ve got, it’s a different canister,” Kellner said. “Different diameter in some cases, and different length. That’s really where it’s going to affect you.”
The exact configuration depends on the truck model, he said, noting that he has a 35-slide presentation, which he didn’t bring, that shows the specs for the canisters for each Kenworth model.
“I know in some cases your body installation is tight to begin with,” Kellner said. “It’s going to be even more critical.”
For example, on class 6 and 7 chassis, depending on the engine and the canister it requires, “you can have anywhere from a two-inch to a five-and-a-half inch back of cab extension,” he said.
“So, I see some of you shaking your heads. Some are going, ‘Yes.’ Some are going, ‘Oh shit,’” Kellner said with a slight chuckle.
Someone in the group asked if the canister is always below the frame rail. Kellner noted that the one depicted in the slide he was showing at that moment was beside the frame rail. But the questioner pointed out the top of that canister was lower than the top of the frame rail.
“Yeah, yeah,” Kellner said. “And it’s going to have the nice, polished fancy steps. Got to look good.”
In the old horizontal configuration, the larger of two canisters was 11 inches in diameter. Replacing them is a 13-inch diameter can, which has had to be moved outboard because of that extra width. That won’t work for trucks with highway fairings because the fairings won’t be able to fit, Kellner said. But for other trucks, an outboard placement of the canister makes it easier to mount PTOs, driveshafts “and so on.”
More engines converting in 2018
Navistar trucks, meanwhile, also now have single-canister aftertreatment systems in their 2017 models with Cummins engines, said Joel Shaw, vocational sales manager for Navistar Canada Inc.
Joel Shaw
Joel Shaw of Navistar demonstrates the various sizes of the single-canister modules.
Navistar’s own N9, N10, and N13 engines will be certified for 2017 with their existing switch-back system, Shaw said. They will, however, switch to a single-can system for 2018.
Canister sizes will increase as horsepower increases, Shaw noted. For the larger engines, that means the canister will protrude about four inches beyond the back of the cab. However, Shaw said, “it’s really insignificant because odds are your body gap is going to be there anyways.”
As Navistar moves into the new configurations, they will open up the right side of the cab, Shaw said. That will enable, for example, a larger fuel tank on the other side “because now you can put your batteries and air tanks underneath the cab here,” Shaw said.
Dan Silbernagel of Freightliner also touched on the single-canister solution in his presentation. “So it actually does improve chassis packaging pretty significantly when you take that additional canister out of there and then the mixing pipe and all of that,” Silbernagel said.
