ANOTHER COOL ENGINE

April 27, 2011 Vol. 7, No. 9

Last time out I teased a bit with brief mention of another new engine design, the very intriguing Scuderi split-cycle engine, yet one more variation on the internal-combustion theme. Lord knows how many there have been in the last century and a bit, though I do know the number's not small. Few of them have had mainstream success over the years, but it's the nature of the creative engineering mind to keep trying. To seize an idea and run with it as long as the money holds out.

I'll get to the Scuderi in a sec.

There's been a spate of news lately about what seem like radical new engine ideas, and for a while it felt like I had an e-mail message every day asking if I wanted to know more about breakthrough Engine X. I'm exaggerating, of course, but the truth is, I've heard about more such innovations in just the last two or three months than in my previous 32-plus years of writing about trucks and sometimes cars.

Should I be surprised? Of course not, because fossil fuels are on the wane in some obvious respects even though they actually remain quite plentiful. With both fuel-cost and environmental pressures relentlessly beating conventional engines about the head -- justifiably or not -- there's a strong imperative to develop internal-combustion motors that consume substantially less fuel while creating sharply fewer nasty emissions and coming in smaller, lighter packages.

The main alternatives -- electric power sort of now for some applications, the hydrogen fuel cell still off in the distant future -- don't really cut it across the board. The diesel/electric or diesel/hydraulic hybrids are great, very effective in some parts of our truck world, but they don't fit every job and won't reach true commercial viability for a few years yet.

There's more promise on the fuel front, I think, from things like algae-based biodiesel, from methane captured at landfill sites, from many other sources synthetic and otherwise. In the short term we have natural gas, of course, which is surging toward the forefront at some speed and has the very enticing virtue of being plentiful. Options like these won't come cheap, sad to say, but we may not have -- or may not be offered -- a choice in the matter.

I don't mean to slight present-day diesel engines here, I'm keen to point out. They're models of largely unrivalled efficiency. And I'd venture a guess that a big-bore 2011 diesel would be 30-50% more stingy in terms of fuel consumption than it was in 2002 if all the engineers and chemists employed to reduce its emissions over this last decade had instead been tasked mainly with trimming fuel use. Ah, but that's another argument for another day.

The new fuels I'm talking about, fossil-based or not, can certainly be used in conventional diesels, though sometimes requiring expensive modifications. And they will be.

Those fuels are also viable in the new crop of engines hoping to break into commercial use, like the two-stroke EcoMotors OPOC that Navistar is helping to develop. I joked that it could run on anything except charcoal briquettes when I first wrote about it a few weeks ago (March 2).. That acronym stands for 'opposed piston/opposed cylinder' and the engine promises two to three times the power density of conventional engines with 50% fewer parts and at least 15% better fuel efficiency. Its small size would bring truck designs that could better exploit aerodynamic potential.

It's sort of a cross between the flat-four VW motor of years gone by and various Junkers aircraft engines that propelled a lot of German planes starting in 1929. The Junkers Jumo 104 variant -- some call the Jumo the most famous engine in diesel aviation history -- had six cylinders and twelve pistons in an opposed-piston configuration with two crankshafts, one at the bottom of the cylinder block and the other at the top, geared together. The pistons moved towards each other during the operating cycle and essentially formed two cylinder heads as they met. The OPOC is a variation on that theme.

There's actually another broadly similar motor on the scene now, and it too can be compared to that old Jumo. In fact the company -- Achates Power -- says its engines are inspired by that same Junkers Jumo. Founded in 2004, Achates says its engine can comply with both EPA10 and Euro6 emissions standards. Like the OPOC, it eliminates the cylinder head and valve train, which reduces heat and friction losses, has fewer components, uses fewer raw materials, saves weight and has a smaller displacement.

San Diego-based Achates claims its engine reduces fuel consumption by nearly 50% compared to a comparable gasoline engine and by 10-15% compared to a traditional diesel. The company says it has fully functioning prototypes with more than 1000 test hours, as well as "leading edge" testing, simulation and analysis tools.

OK, SO WHAT ABOUT THE SCUDERI? Well, start thinking Miller cycle, which leaves the intake valve open longer than in the conventional four-stroke 'Otto' cycle engine that we know and love. You end up with what's almost a fifth stroke because the compression stroke really happens in two cycles. A Miller cycle engine needs a supercharger, I believe.

Scuderi Group boss Sal Scuderi calls his 'Split Cycle' variation on that theme "the perfect Miller-cycle engine", though there's no fifth stroke, and earlier this month he presented two technical papers on his split-cycle motor and its valve-control system at the SAE Congress in Detroit. His company hails from West Springfield, Mass., a seemingly well funded engine development outfit that's intent on re-engineering the conventional four-stroke engine. Its global patent portfolio contains more than 476 patent applications filed and 154 issued in 50 countries.

The basic idea here is simple enough -- it's really all about firing AFTER top dead center, not precisely AT top dead center -- a radical approach that's been hard to achieve, Scuderi told me in a phone interview a couple of weeks back. He's done it, however, and has discovered that adding a turbocharger to his engine works a treat. That's the latest breakthrough.

He quotes studies that show boosting the engine with a turbocharger decreases the BSFC (brake-specific fuel consumption) up to 14% while a simultaneous increase occurs in the engine’s power BMEP (or brake mean effective pressure) by 140%. At the same time, he says, the engine can be reduced in size by just under 30%.
 
Like conventional four-stroke designs, the combustion cycle of the Scuderi engine has two high-pressure strokes -- compression and power -- and two low-pressure strokes -- intake and exhaust. The power stroke is positive work, Scuderi explains, or the energy that's produced by the expanding gases to create mechanical work. The intake, compression and exhaust strokes are all negative work, or the energy that the engine consumes in the process. By separating the compression cylinder from the power cylinder and by using a standard turbocharger to convert recovered exhaust-gas energy into compressed air energy, the size of the compression cylinder can be downsized to achieve substantial reductions in negative compression work.
 
“The Scuderi Engine gains a massive advantage from turbocharging, Miller-like valve-control strategies, and extended expansion that is simply not possible with conventional engine designs,” says Scuderi. “The net result is a smaller, higher-performing engine that yields significant gains in volumetric efficiency and power as well as reducing BSFC."

The Scuderi engine divides the four strokes of a combustion cycle between two paired cylinders -- the left cylinder functions as an air compressor, handling intake and compression, while the right cylinder handles combustion and exhaust. Key to Scuderi’s split-cycle design is that it compresses the air before it fires. By optimizing the split-cycle concept, the engine when fully developed will reduce NOx emissions up to 80% and improve fuel efficiency by 50% compared to a conventional gasoline engine. The engine requires one crankshaft revolution to complete a single combustion cycle and is projected to have higher torque, thermodynamic efficiency, and lower emissions than possible with today’s engines.

Scuderi adds that further studies will soon be announced, showing "impressive results" of the Scuderi Split-Cycle engine modeled in a 2011 Nissan Sentra. ”

Don't be left with the impression that this only works with little gas engines. Scuderi's walking the big, hairy diesel trail too, though the interest so far is mainly from the four-wheel world. Only one truck maker -- unnamed, but not North American -- has so far sniffed around. His plan is not manufacture engines, by the way, rather to license his technology.

For a video explaining the Scuderi basics, go here.

To listen to an audio podcast of Sal Scuderi discussing the recent lab breakthrough, go here.

Hear the first prototype running here.

MEANWHILE, KENWORTH'S T700 WAS HONOURED as the American Truck Dealers Heavy Duty Commercial Truck of the Year at the recent annual ATD convention in Phoenix. This, of course, runs counter to what I wrote in my April 13th newsletter when I blithely announced that Peterbilt's Model 384 had won the day. The Pete did win the ATD prize, but did so in 2010. Embarrassingly enough, the year-old press release somehow migrated to my screen and in my rush to post that last newsletter, I assumed it was current. A major gaffe that caused a stir in both Kenworth and Peterbilt offices as you might imagine, but I'm heartened to say it was absorbed with much grace by all concerned. My apologies.

In any event, the T700 -- which Kenworth calls its "most aerodynamic truck in company history -- equipped with the PACCAR MX engine seems like a worthy winner. It was selected by a judging panel of journalists from leading American truck publications. Major judging criteria included innovation, design, driver and owner satisfaction, ease of maintenance, and safety.

The T700 was designed through the extensive use of computational fluid dynamics to optimize its aerodynamic profile. It has SmartWay certification. Other features include "state of the art" multiplexed instrumentation. The new Kenworth NavPlus – a proprietary in-dash, PC-based system with truck-specific navigation, vehicle data, hands-free phoning, audio controls, camera inputs, roadside assistance, and optional Internet access – will be available this year.

The PACCAR MX engine is available with 380 to 485 hp and torque up to 1750 lb ft on selected Kenworth class 8 models.

And one other Kenworth note: the tough T800 model is celebrating its 25th anniversary this year. Seems hard to believe it's been that long, but the company has pumped out more than 235,000 T800s throughout the U.S. and Canada since its launch in 1986.
 
The T800 is Kenworth’s all-time most diverse truck, the company says, and its top seller in vocational markets.

ALLISON UNVEILED A NEW 10-SPEED transmission at the recent Mid America Trucking Show. It incorporates Allison's torque converter with twin countershafts and Allison says it'll bring productivity and fuel efficiency to urban P&D work, but still deliver fuel economy while cruising.

It's not quite ready for prime time but was at the show in a demonstration vehicle.

“Initial in-vehicle demonstration tests have allowed us to document some very nice gains in fuel economy and we achieved increases in a vehicle's miles per work day,” according to Lou Gilbert, Allison's director of North American market development.

“Our testing has shown this new transmission offers better fuel economy than an automated manual in the targeted duty-cycle markets for which it was developed,” he claims.

Allison expects truck OEMs to begin offering the new transmission in the fourth quarter of 2012.

FINALLY, A CONFERENCE REMINDER. Green Fleet Expo, billed accurately as Canada's premiere 'green' fleet event, will be held on Thursday, June 2 and Friday, June 3 at the Courtyard by Marriott hotel in Hamilton, Ont. The two-day registration fee is only $75, and the tariff for just one of those days is $50. You can't go wrong.

This very useful conference is nowadays presented by the Ontario Ministry of Transportation, partnered by the City of Toronto's Fleet Services Division, the City of Hamilton's Public Works Department, and Fleet Challenge Ontario. The two cities launched the event on their own several years ago.

Yours truly is among the speakers on day one, and I'll be talking about advanced fuel-saving technologies. Other sessions will cover things like electric power and measuring your fleet's actual 'greenness', and one will feature fleet managers from four Canadian municipalities describing their green fleet plans.

Day two's activities will mostly take place at the Canadian Warplane Heritage Museum near Hamilton International Airport, featuring an exhibition of green vehicles and ride-and-drive opportunities.

For more information contact Drew Shintani by e-mail at dshintan@toronto.ca or register online here.

THIS NEWSLETTER IS PUBLISHED every two weeks. It's a heads-up notice about what's going on with trucking technology as well as what you can see at  todaystrucking.com where you'll find in-detail coverage of nearly everything that's new. I also write about interesting products that may not have had the 'air play' they deserved within the last few months.

I should remind you that I don’t endorse any of the products I write about in this e-newsletter, nor do I have the resources to test them. What you’re getting is reasonably well educated opinion based on more than three decades in trucking. And in the case of individual product items, I’m just presenting simple news from the manufacturer or service provider, with the hyperbole mostly removed and clarification applied.

If you have comments of whatever sort about Product Watch, or maybe you've tried a gizmo I should know about, please contact me at rolf@newcom.ca.

AIR MANAGEMENT SYSTEM

(April 26, 2011) -- Bendix package aims to improve performance and fuel consumption

WHEEL INTEGRITY

(April 26, 2011) -- The Zafety Lug Lock from Spectra

NON-DRIVER CSA TRAINING

(April 26, 2011) -- From J. J. Keller, a CSA training program for everyone else

REEFER CONTROL

(April 26, 2011) -- New APX control system from Carrier Transicold improves reliability

6X6 KENWORTH T370

(April 26, 2011) -- T370 6x6 configuration includes factory-installed front drive axle