Green Options » engine

Low Cost Gas Engine Innovation Doubles Fuel Economy

Nick Chambers — Thu, 26 Jun 2008 15:15:02 +0000

Revetec, a little known company from the Gold Coast region of Australia, may be on to something huge: they’ve created an engine that is 50% smaller, 50% lighter, has 50% lower emissions and is cheaper to manufacture than a conventional internal combustion engine of the same horsepower. Oh yeah, did I mention that it doubles the fuel economy too.

What that means is a car like the 2007 Toyota Yaris, which is rated at 40 mpg on the highway, would get 80 mpg with a Revetec engine.

This isn’t some hoax… They have a prototype which has been attached to an actual vehicle and independently tested to substantiate their claims.

In personal communication with Mr. Brad Howell-Smith, the Chairman, Inventor and CAD Designer for Revetec, he says “road tests have estimated that [the engine] uses around 50% less fuel than a conventional engine” and if it were converted to run on diesel, that performance gain could be much higher.

Also, because the engine delivers higher torque, and can perform and operate well at much lower rpm’s than a conventional one, the noise levels are lower.

To illustrate how serious he is, Mr. Howell-Smith said that since 2001 his company has been in touch with the US Military Head of R&D for the Southern Hemisphere on a “regular basis” for the purpose of developing one of their engines for light aircraft.

The current prototype engine, the X4v2, is what Revetec calls a “controlled combustion engine.” The meat of the engine comprises two counter rotating multilobate cams, which are acted upon by two pairs of diametrically opposed pistons which are rigidly interlinked by connecting rods.

If that sounds like complete gibberish to you, you’re not alone. Which is why I included an animation of the process to the left. A more simplified animation of the general motion of an engine of this sort is also included below.

Mr. Howell-Smith said that “if [the engine] uses 50% less fuel given that it has the same top end as a conventional engine, emissions would be reduced by 50% if the bottom end was utilized.”

What does all that stuff about “bottom end” and “top end” mean? The X4v2 has a huge amount of torque over a much larger range of rpm’s than a conventional internal combustion engine.

If a person were to drive a vehicle fitted with this engine in a non-aggressive fashion and keep the rpm’s at the “bottom end” (meaning no “jack-rabbit” starts) they could expect to see a 50% reduction in emissions.

Alternatively, according to Mr. Howell-Smith, a person could see a 30% reduction in fuel use and a 30% reduction in emissions if they used the full acceleration power of the X4v2 all the time. This would provide a 20% increase in acceleration capabilities.

We could debate about whether or not the internal combustion engine has a place in the future of transportation or whether it’s going to be all-electric or fuel cell or whatever… but in the meantime, Revetec has a product that could revolutionize the the transportation industry now, and provide a much needed large reduction in fuel consumption and emissions.

Just imagine a bunch of 80 mpg Toyota Yarises (Yarisi??) running around all over the place. A little scary, I know, but… an 80 mpg conventional automobile? I must be dreaming, wake me up before I get too excited.

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Image Credits: Revetec

Turbine Engine: No Pistons, No Lube, 30% Better Fuel Economy

Nick Chambers — Mon, 09 Jun 2008 16:58:03 +0000

There are more than 5,000,000 heavy duty trucks running up and down US highways each day. Every one of those trucks gets an average of 7 mpg, carries upwards of 200-300 gallons of diesel, and spews out potentially harmful emissions.

Like it or not, we depend on them to bring us our food, fuel, and products for everyday living. It’s a connection that most of us often forget about, only remembering it long enough to curse them as they slow us down on the highway.

It’s also an industry that has recently been hit hard by soaring fuel prices, and now, with the average price of diesel in the US at $4.70/gallon and climbing, it’s sure to get worse.

Needless to say, there’s a rising cacophony of voices within the trucking industry clamoring for relief. Most of this noise currently comes in the form of wanting a break in fuel prices, but really that’s just a temporary fix. Any solution with sticking power would have to offer both economic and environmental benefit — you know, win-win.

Enter Turbine Truck Engines. The company has developed an engine for heavy duty trucks called the Detonation Cycle Gas Turbine (DCGT). Key features of this engine technology include:

Uses over 30% less fuel than current heavy duty engines
30%+ fewer emissions including nitrogen oxide (NO, NO₂, N₂O₂) and carbon monoxide (CO)
Operates on all fuels and mixtures of fuels: biofuels, hydrocarbon fuels, hydrogen and synthetic
Has few moving parts, requiring much less maintenance
Has no pistons or valves, and uses no lube oil, filters or pump
Is air cooled and lightweight (less than 2 lbs. per hp)

The company has been aggressively seeking investors recently and last year won the prestigious Frost and Sullivan Award for Technology Innovation.

Currently Turbine Truck Engines holds several patents and has a few prototypes under its belt. When (and if) their technology finally reaches the market, the combined savings on maintenance and fuel, as well as environmental benefits, could make this engine extremely popular with truck drivers and trucking companies worldwide.

What do you think? Is it worthwhile to invest in this type of technology, or should we move past fuel altogether and focus on other things such as our rail infrastructure for movement of goods? Is that even possible? Are big rigs a permanent feature of our society? Is there any way to run them entirely on electricity?

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Image Credit: Turbine Truck Engines

Scania’s Ethanol Diesel-Engine, Runs On Biodiesel Too

Clayton B. Cornell — Tue, 15 Apr 2008 20:26:28 +0000

Scania (part of Volkswagen) builds modified, heavy-duty diesel engines designed to run on almost pure ethanol (E95, or 95% ethanol, with a 5% ignition improver).

If that sounds weird, that’s because it is. US auto manufacturers make a big deal out of converting cars and trucks to run on ethanol/gasoline blends of up to 85% ethanol. Scania has done better than that for 15 years, and guess what, their engines can run on 100% biodiesel too, without any modification.

Scania’s compression-ignition (CI) ethanol engine is a modified 9-liter diesel with a few modifications. Scania raised the compression ratio from 18:1 to 28:1, added larger fuel injection nozzles, and altered the injection timing. The fuel system also needs different gaskets and filters, and a larger fuel tank since the engine burns 65% to 70% more ethanol than diesel (whoa! see below). The thermal efficiency of the engine is comparable to a diesel, 43% compared to 44%.

While Scania originally introduced this technology for “heavy commercial vehicles in urban operation” (city buses), they’re now extending it to trucks as well. Scania maintains that with existing technology, the transition to renewable fuels can be painless. Since in the last 15 years they’ve put 600 ethanol buses on the road (mostly in Sweden), the company seems to know what it’s talking about.

Scania is also working to develop ethanol refueling infrastructure, which should make it easier for smaller transport companies to invest in ethanol-powered vehicles.

But why not use biodiesel, since ethanol requires about 1.5x more fuel usage? Scania’s answer may raise a few eyebrows: “the farming capacity [for biodiesel] is insufficient for the huge need foreseen for the transport industry.”

Unless you take EU spokesman Michael Mann’s comments seriously (he said that Europe can grow enough fuel to meet 10% of it’s transportation fuel), Scania must be betting on cellulosic ethanol. The intensifying food vs. fuel debate isn’t taking this issue lightly, as I’ve written about here and here.

In any case, Scania’s work seems to indicate it might not be as hard to create engines that run on alternative fuels as auto manufacturers maintain.

Posts related to Ethanol and Biodiesel:

European Union Defends Biofuel Targets As Food Prices Soar
Biodiesel Myth (Or Fact?) #23: Biodiesel is Raising Food Prices
Mercedes 40-MPG Diesel Hybrid: Cleanest SUV on the Planet
How Biodiesel Fuel-Cells Could Power The Future (And Your Car)

[Via]

Need a New Car? Nope, Just a New Engine!

Benjamin Jones — Tue, 25 Mar 2008 02:34:01 +0000

Image source: motoringfile

Engine Repower is a new (as far as I can tell) service that gives car owners the option of replacing their old, worn out engine with a rebuilt engine of the same vintage instead of simply buying a new car or repairing specific problems. When a first saw this page, I was very interested, as I am a proponent of keeping your car as long as possible to reduce wasteful manufacturing processes, even in the face of promises of lower emissions made by newer cars.

For more on repowering, follow the jump!

Here’s what Engine Repower has to say about their service:

Technology and auto manufacturing have advanced dramatically in the past two decades. Cars and trucks last longer. Paint is better. Bodies are more corrosion resistant. Interior materials are more durable, and even suspension and other components last longer. So when an engine “dies,” it does not have to be the end of your vehicle. When a car or truck suffers major engine damage, the first response and reaction of many consumers is to buy a new or used vehicle. Sometimes disposing of your current vehicle might make sense, but often it’s simply not necessary.

Obviously, being an advertisement, they are very high on themselves, but they do make some good points. When cars die, it seems it is most often due to accidents or blown engines. Very rarely do cars rust so badly or generally devolve to a point of undrivability before the engine begins to have trouble. Also, one of the biggest issues with emissions from old vehicles is that those vehicles have fallen out of spec and are no longer getting the best fuel economy or releasing the least emissions.

The Engine Repowering Council seems to focus on domestic vehicles, but using their find-a-shop feature, it’s likely that you can find someone to rebuild an engine of almost any make. These engines almost always come with warranties and, in my opinion (as someone who has worked at a shop in the past), will be rebuilt as carefully as anything else coming from that shop. So, if you’re considering this, pick a shop you know and trust, and that offers a good warranty.

While the service is certainly not ideal (you can’t just put a newer, cleaner engine in an old car), the ability to put life and reliability back into an old car is about as close as you can get to recycling and reusing in the automotive world.

Car Hacker’s Hummer Gets 60 MPG

Clayton B. Cornell — Fri, 14 Dec 2007 18:50:16 +0000

If you haven’ heard of the Motorhead Messiah, Jonathan Goodwin, let me introduce you: he hacks cars for a living, and he can get 60 mpg out of an H3 Hummer while doubling the horsepower and cutting emissions in half. Unbelievable? Yes, but this is no joke, and it’s doesn’t defy the laws of physics either. The hacked H3 is a hybrid with the gasoline fuel system removed. In its place, Goodwin installed a biodiesel-burning jet turbine to recharge the electrical system:

Goodwin leads me over to a red 2005 H3 Hummer that’s up on jacks, its mechanicals removed. He aims to use the turbine to turn the Hummer into a tricked-out electric hybrid. Like most hybrids, it’ll have two engines, including an electric motor. But in this case, the second will be the turbine, Goodwin’s secret ingredient. Whenever the truck’s juice runs low, the turbine will roar into action for a few seconds, powering a generator with such gusto that it’ll recharge a set of “supercapacitor” batteries in seconds.This means the H3’s electric motor will be able to perform awesome feats of acceleration and power over and over again, like a Prius on steroids. What’s more, the turbine will burn biodiesel, a renewable fuel with much lower emissions than normal diesel; a hydrogen-injection system will then cut those low emissions in half. And when it’s time to fill the tank, he’ll be able to just pull up to the back of a diner and dump in its excess french-fry grease–as he does with his many other Hummers. Oh, yeah, he adds, the horsepower will double–from 300 to 600.

Power and Efficiency? The notion seems contrary to everything we’ve seen from the auto industry in the last 20 years. But Goodwin is disproving the ’status quo’ by concrete example, the Hummer hybrid being one of many. He’s gotten 100 mpg out of a Lincoln continental and developed a bolt-on kit for diesel engines that doubles fuel economy and reduces emissions by 80%. Goodwin’s a model iconoclast, with a love for the environment and big vehicles.

So Goodwin decided to prove that environmentalism and power could go together–by making his new lemon into exhibit A. First, he pulled the gas engine so he could drop in a Duramax V8, GM’s core diesel for large trucks. Diesel technology is crucial to all of Goodwin’s innovations because it offers several advantages over traditional gasoline engines. Pound for pound, diesel offers more power and torque; it’s also inherently more efficient, offering up to 40% better mileage and 20% lower emissions in engines of comparable size. What’s more, many diesel engines can easily accept a wide range of biodiesel–from the high-quality stuff produced at refineries to the melted chicken grease siphoned off from the local KFC.

Goodwin’s endorsement of diesel engines makes sense, and he has a 3-part plan to wean the nation from gasoline. First, aggressively mass-produce diesel passenger vehicles. Converting just 1/3 of our nations passenger vehicles and light trucks to diesel would eliminate Saudi Arabian oil imports. Second, start producing diesel-electric hybrid cars, the holy-grail for biodiesel enthusiasts. After reading this article I’m convinced it’s possible (the whole ‘diesels are too heavy argument’ is ridiculous). And third, produce hybrids with a dual fuel mode, such as hydrogen or propane injection. I’ve heard of propane injection, which shoots a small amount of propane into the combustion chamber along the diesel fuel, increasing mileage, horsepower, and decreasing emissions.

“Detroit could do all this stuff overnight if it wanted to,” he adds.

For a thoroughly interesting read, see the FastCompany.com article (November 2007).

Photo Credit.