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A New Lease On Internal Combustion
Somnus suggests we check out the latest issue of MIT's Technology Review, where researchers describe how they can dramatically boost engine output and efficiency by preventing pre-ignition, or "knock." How they do it: "Both turbocharging and direct injection are preexisting technologies, and neither looks particularly impressive... by combining them, and augmenting them with a novel way to use a small amount of ethanol, Cohn and his colleagues have created a design that they believe could triple the power of a test engine."
How long before this is bought/patented by oil companies and sealed away in the same warehouse as the Ark of the Covenant.
...become simpler with the addition of a small amount of ethanol.
In a large glass.
Wow, this is yesterdays news. People in the tuning industry have been controlling "knock" in various ways for a long time. Either by raising the octane number on your ful (add ethanol or booster), so that you can had move advanced ignition timing, or simply retarding your timing and using the same octane rating fuel as you normally use
Move sig!
Congratulations You've discovered the same thing as Rudolph Diesel except that you don't quite have it right. You don't need to use ethanol or port injection ditch both of those and use good ol fashioned vegetable oil. 0 preignition and you can turn the boost way up on a tiny engine.
This headline made my brain spontaneously combusit.
Badass Resumes
"Both turbocharging and direct injection are preexisting technologies, and neither looks particularly impressive... by combining them, and augmenting them with a novel way to use a small amount of ethanol, Cohn and his colleagues have created a design that they believe could triple the power of a test engine."
Have those two NOT been previously combined before, or what?
In any case, triple the power sounds awesome. If real, I want that tech in my motorcycle. As a two stroke.
Just with a spark plug instead. This is similar to water injection and water/methanol injection on a turbo gasoline engine.
I suppose my first question is, when the owner inevitably lets the ethanol run out, what happens? Can the engine computer dial down the boost enough to prevent detonation? Or does the engine just have to shut down?
That aside, it's always great to improve internal-combustion efficiency, but the real solutions will have a more dramatic effect than this. My own view is that the solution should be a plug-in series hybrid with about 60 miles of electric-only range and the ability to run maybe 400 more with the engine providing generator power. This would not seriously compromise the essential attributes of modern cars, while *dramatically* (think 80% or more) improving their fuel economy in many real-world usage patterns.
Then we should have nuclear power behind all those 220v outlets... and 90% of cars should be much smaller, with people able to obtain bigger trucks for big jobs on demand from time-share or rental companies... a guy can dream, can't he...
This sounds an awful lot like a modern diesel engine. Modern diesels are turbocharged and use common-rail injection to achieve insane pressures at the injector heads (for really fine atomisation of the fuel), which directly inject into the cylinder. I believe the newer engines even stagger the injection during the compression and combustion cycles too to achieve more power and cleaner burning.
(NB: I'm not a revhead so I might be talking shit)
Even promoting more efficient cars.
Nothing great was ever achieved without enthusiasm
Once you've filed a patent (one synonym of "patent" is "obvious") and received as much news play as this has, it can't be hidden.
Any attempt to hide it will get as much bad press as Chevron's blocking of high-capacity NiMH batteries for EV's through their Cobasys venture. It will invite things like compulsory licensing.
Sustainability and energy independence essay
There really isn't a shortage of power in modern car engines. What we need is efficiency, and not mere volumetric efficiency at that. The article implies that a smaller engine would be more efficient since it could be lighter, but even if knock is controlled, it will have to be a very stout block with either heavy components (rpm limiting) or expensive titanium components. Knock isn't the only thing that wears/damages a high performance engine. Heat (and heat cycling), friction, and lubrication all have to be carefully managed.
How do we go from this:
...Cohn and his colleagues have created a design that they believe could triple the power of a test engine, an advance that could allow automakers to convert small engines designed for economy cars into muscular engines with more than enough power for SUVs or sports cars.
A vehicle that used this approach would operate around 25 percent more efficiently than a vehicle with a conventional engine.
to this:
does a 25% increase in efficiency translate into tripling the power output?
You can't handle the truth.
Um, we figured this out decades ago. Race engines types of higher octane solutions to raise boost and compression. Methanol, Ethanol, Alcohol, Race fuel. It's simple chemistry. Pure gasoline packs more energy but is unstable, additives like Ethanol raise octane ratings making the fuel more stable but packing less punch (energy per volume of fuel). E85 is equivalent to 108-116 octane, good stuff, but not for a Buick. Throw it into a regular car and you need to suck down more fuel to get the same output, however, throw it into a high compression or high boost engine, and you can more effectively make power. High compression engines are definitely more efficient, ask me how I know. I run 12:1 on 93 octane and get 37MPG on the highway, my car also runs 13s at the track. Before I went high compression, I made about 30MPG on 87 Octane. Calculate this out and I save money even though I'm paying 20c more per gallon. This is racing technology and it's not even remotely new. The only thing that's new is E85 is available at more places and cars are being set up to run E85. If you put E85 in a regular car, you're an idiot. If you buy a car that's supposed to run E85, make sure that it's set up to make the most out of the fuel and never go back to standard gasoline.
Wow these guys should sell this technology to the drag racing community...oh wait they have been burning alcohol for years to give them the ability to, reduce intake charge temperatures, reduce pre-ignition in high compression and large boost scenarios.
Yes we should be burning more ethanol and it is a outstanding engine fuel however pre-blending by the oil companies is a crappy idea. How about blending the fuel at the pump so I can buy pure ethanol and or blended. If one could buy pure ethanol at the pump then those of us that wanted to take advantage of high compression engines with insane boost pressures could do it, and those that wanted to run 15% passenger car run of the mill under powered plants could do the same.
Got Code?
This should be a lot more accurate than the original summary.
Blah blah sig blah blah blah irony blah blah
This scheme is a stopgap, pure and simple. 30% is nowhere near good enough — we need plug-in hybrids to displace 80% of our liquid fuel (for starters), not 30%. But when you compare the efficiency losses of gasohol and E85 to the efficiency gains of the smaller turbo engine, and consider that this engine has the potential to run on 100% ethanol (complete flex-fuel operation) and on ethanol with some admixture of water (reducing the energy required for distillation and allowing the ethanol to be shipped by pipeline where it might pick up water), this is a huge improvement.
Unfortunately, it won't be good for much if we have to trade off food against motor fuel.
Sustainability and energy independence essay
So we know that we're talking exclusively about ethanol, but don't know anything about any claimed performance or efficiency gains. If I was trying to quantify the benefits of something and just said "would be a rocket with our technology" I'd expect to get a kick up the arse and a suggestion to try again. Presumably, since MIT is an academic institution there is something actually written up somewhere?
Aside from the ethanol bit, BMW already uses direct injection and turbocharging to get 300hp, 300ft-lb and 30 MPG (highway) out of a 3 liter I6. N54 engine from the 2007 335: http://www.bimmerfest.com/forums/showthread.php?t= 144546
Seriously. Direct injection, fine tuned control of timing, and turbo charging all put together is what you see in a large number of hobbiest race cars. Drag, autocross, whatever. A lot of times they'll skimp on tolerances thus reducing the reliability of the engine, but it's not at all uncommon to take a solid normally aspirated engine and triple it's output with some good planning and bit of machine work.
I've personally never added a turbo where there wasn't one before, but I HAVE done machine work, timing work, and injector work. I've taken a car from 220 hp to 290 hp with no detriment to the mileage, just better fuel/air mixtures and precise timing. It doesn't surprise me at all that people who've actually studied combustion instead of working on it for fun have been able to triple the output.
What's surprising is how inneficiently tuned a lot of engines come from the factory.
if it will become the next redneck toy to show off at the Burger King's parking lot.
Meh, they'll stick to the neon lights.
Congrats to MIT for discovering already in use technology!
Then again, maybe its new to them because Americans don't like LeMans?
Please drop your internal combustion research. This is a dead-end technology that relies on us burning stuff that we buy from terrorists. Please focus your efforts on a fusion engine that uses garbage like in the movies. The flying car part can wait though. Just get the fusion engine going. Thanks.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
What would you say to some nice ethanol?
I'd say, "Don't get too comfortable in that glass!"
Sony ha
Do you really think that the Big Three will adopt new engine technology?
You can still find push-rod engines being built today...
Why is this rated "funny"? Mythbusters did this:
"Although there's no word on damage to the engine from using used cooking oil, a diesel-fueled car did run on it. However, the MythBusters speculate that once this alternative fuel achieves a significant interest level among the public, used cooking oil will be hoarded as a saleable commodity. The used cooking oil also did not quite fit the requirement of improved fuel efficiency, as it yielded approximately 10% less distance for an equivalent amount of diesel."
See here and here (scroll down)
Sony ha
The '07 MINI Cooper'S has a 4 cylinder 1.6 liter direct-injected twin-turbocharged engine - and since most fuel in the US now contains 10% ethanol, I'd say the "experimental" technology these guys are pushing is already out there in at least one production car. The problem with knocking has been nailed a bazillion years ago - just about all modern cars have an anti-knock sensor that can richen the mixture if it detects signs of knocking - but with high octane gasoline - it only very rarely has to actually do that - so the "problem" of knocking isn't really there. The only time the MINI actually does something like that is when the dumb user filled the thing with regular low-octane gas instead of 'the good stuff'.
Add to that that the MINI has goodies like electric oil, power steering and water pumps that can actually be turned off (rather than merely bypassed) when not needed - so the engine reaches it's most efficient temperature faster and you aren't burning fuel circulating fluids that don't need to be circulated yet. It has computer controlled inlet and exhaust valves - so the timing is infinitely variable - and can be varied separately for each cylinder. For short bursts of accelleration, the car has an 'overboost' feature from the turbo - which won't help you much for prolonged hard accelleration - but is great for a rapid burst of speed for overtaking, blasting out of a corner (FUN!) or blowing away those bloody ugly Scion xB's at traffic lights (a personal mission of mine, I might add).
www.sjbaker.org
With all the new technology constantly being tested by the auto racing community, it's hard to believe that any "breakthru" could truly produce such a large increase in horsepower. The Formula One teams spend hundreds of millions of dollars for modest increases in performance. If it were taht easy, it would have been done already.
If they use this to increase turbocharger pressure, I'd expect turbo lag [1] to become a problem again. It'd be better to increase the compression ratio instead. Or maybe combine ethanol injection with some of the variable-compression designs that have been surfacing lately.
Also: why would premature combustion still be a problem in a direct-injection engine? It should be possible to inject the fuel when it is needed, and not before. Or would that lead to timing problems?
1: turbo lag is the delay between pressing the accelerator and power output rising. It's affected by the size of the turbocharger, boost pressure and a few less important factors.
I listened to a CSIRO podcast about this about 6 months ago. With normal combustion as you increase the pressure you also increase the problem of early ignition (knock) due to a side effect of the temperature increasing. What they found out was if you add ethanol it has a "cooling" effect to the combustion chamber thus allowing you to increase the pressure in the combustion chamber. For auto makers this means they can use smaller lighter motors in a car to gain the same amount of power output.
I'm intrigued to imagine what they could do if this ethanol based charge cooling works out. I'm already forced to put 15% ethanol in my Audi V8 (sadly NOT an RS4), living in NYC, but if this works out maybe I can support the farmers AND have a powerful car for the weekends (I commute on the subway).
What!? Most fuel in the US contains 10% ethanol? Only 1/8th of the Gas in the sates has ethanol.
a nol.html
http://www.eere.energy.gov/cleancities/blends/eth
You either need to read the article or, if you have, brush up on your reading comprehension skills. The technique used in the article is supposed to allow them to push the turbo pressure much higher than any modern car can handle, even when using high octane fuel. They're talking about using a separate direct injection system to pump a small amount of pure ethanol into the cylinder out of phase with the gasoline. It would cool the cylinder enough to stop knock when the gas is injected at extreme pressures. Supposedly, you would have to replace the ethanol about as often as you have to replace the oil (every few months).
Next time, please try reading the article instead of seeing "ethanol" and "turbocharger" in the summary and shooting your mouth off.
-GameMaster
Rules of Conduct:
#1 - The DM is always right.
#2 - If the DM is wrong, see rule #1
People have long known that ethanol fuels have high octane ratings (the measure of how knock resistant a fuel is).
People have also long known that turbo charging an engine is a great way to extract more power out of a small engine.
People have also known that direct injection allows you to reduce the tendency to knock since it lets you inject fuel into the hot engine at the very last second - reducing the amount of time the air/fuel mixture has to heat up.
And guess what? Mazda produces cars today that has both direct injection and is turbo charged. For example, the MazdaSpeed 3.
It's 2.3 liter engine produces 263hp and 280lb/ft of torque and has an EPA fuel economy rating of 20/28mpg. So yes, while it does provide good power and decent gas mileage, it's nothing earth shattering compared to turbocharged cars without direct injection.
The engine has a very high compression ratio for a turbo charged gasoline engine (9.5:1), especially one that pushes over 15psi of boost into the cylinders. That is direct injection working for you.
For example, the slightly bigger turbo charged 2.5 liter Subaru WRX engine has a compression ratio of 8.4:1 and maximum boost of 11.6psi is rated at 230hp/235lb/ft of torque (though it is admittedly underrated) with similar fuel economy as the Mazdaspeed 3 considering that it is all-wheel-drive (20/26mpg EPA). The more powerful WRX STi has the same 2.5l displacement, 8.2:1 compression ratio and a bigger turbo pushing 14.5 psi is rated at 293hp/290lb/ft of torque but less fuel economy, 18/24mpg.
Unless there is a lot of potential still to be found by combining these 2 technologies, I see it as more of an evolution rather than a revolution. Perhaps a 1.0 liter engine would be able to muster 120+ hp/torque but I find it hard to believe that it could achieve mileage ratings significantly higher than a hybrid. And you still can't turn the engine off when idling or coasting down hill.
So how about a direct-injection, turbo-charged, atkinson cycle hybrid and combine the best of all technologies?
You can go buy an engine right now that uses turbocharging, high static compression, and direct injection. The Audi 2.0T FSI engine, featured in the A3, A4, VW Jetta, and VW Passat feature this.
Ethanol is an octane enhancer (which prevents pre-ignition), and lets you run either higher boost, higher static compression, or more ignition advance.. all of which make more power (or more efficiency), and none of which, even in combination, will triple the output OR fuel economy. Many auto enthusiasts are discovering the benefits of running E85 in their modified turbo charged cars, since it is effectively 104 octane fuel, but at normal fuel prices. Ethanol also burns cooler than gasoline so is especially nice on turbocharged engines where unrecaptured heat and absolute exhaust temperatures are your enemy.
My opinions are my own, and do not necessarily represent those of my employer.
Wow, you dipshits know everything.....why are folks even bothering to go to MIT!?!?!
Knock sensors and computers don't add power, they give the engine as much advance as it can take short of detonation.
This sort of setup will inject a cooling shot of alcohol AT THE PRECISE BEST TIME (unlike the WWII fighters which just poured it on like some nitro funny car's MECHANICAL injection)
This is a good idea which MIGHT make a very measurable difference in future cars.....
So unless you're a mechanical engineer WITH DECADES OF EXPERIENCE IMPROVING THE INTERNAL COMBUSTION ENGINE, STFU.
Both turbocharging and direct injection are preexisting technologies, and neither looks particularly impressive. Indeed, used separately, they would lead to only marginal improvements in the performance of an internal-combustion engine. Really? So there aren't people slapping large turbochargers on little 3 liter supra engines and increasing the engine output 5-fold? Or is that only marginal?
That aside, the problem with this is that a turbocharged engine at full output is very inefficient. A larger naturally aspirated engine will always be more efficient than the small turbocharged engine of the same maximum output. That's because a lot of energy is wasted compressing the intake charge, more than can be made up for with the displacement decrease, even with the newest fanciest garrett turbos. The only merit efficiency-wise of turbo engines is engine efficiency at low loads (when the engine is not under boost) relative to the maximum output. There is obviously a balance to be struck here, and that's why 18 wheelers have big v8's with turbo chargers, rather than even bigger engines or smaller engines running under high pressure. Designing a motor vehicle is always a balancing act, and in most cases a turbo is not helpful because of the cost, reliability and other shortcomings versus the benefits.
Recently, car makers have started using direct injection to combat preignition that can damage an engine. It allows them to run leaner fuel mixtures, higher compression and more aggressive spark timing, improving the power/efficiency of engines. Direct injection has the exact same benefit with turbocharging. There are no compounded benefits from mixing the two technologies.
This link was posted by someone else responding to the original post.
# Turbo_Jetfire
http://en.wikipedia.org/wiki/Oldsmobile_V8_engine
If you read the section, you'll notice that, even without fancy computer controls, they had designed the engine to retard timing when the reservoir was empty. The reason they discontinued the engine really was that people just didn't bother keeping the thing filled.
Unfortunately, people are lazy. Unless the system is designed to kill the engine when the ethanol tank runs dry they won't bother keeping it full. If you did kill the engine that way they would, simply, refuse to buy the car (as was the case in the 60's).
-GameMaster
Rules of Conduct:
#1 - The DM is always right.
#2 - If the DM is wrong, see rule #1
Turbocharging already gives about a 2-to-1 boost while avoiding the knock limits - and it doesn't require a second tank, just higher-octane gas (which, at current price levels, doesn't command all that high a cost premium over regular). So the claimed 3-to-1 boost, while a significant further improvement worth going after, isn't as big a jolt as the standalone description would make you think.
(My commuting vehicle is a 4-cylinder turbo - and 15 years old. It has 100k miles on it and I'm rebuilding the vehicle around it at a cost of about 8 grand - suspension, tranny, major engine service - because I can't get an equivalently performing vehicle on the current new market at any reasonable price. That's apparently because adding a turbo to a small passenger car has enough downsides that the public isn't interested. (Or perhaps because the auto companies' marketing departments are totally clueless.))
Direct WATER injection of a high-compression ALSO gets this 3-to-1 or better boost. It has the same advantages as the alcohol injection at less cost: Higher power, reduced preignition, etc. But you can go even farther, since water won't, itself, combust.
You also get more efficient transfer of heat to mechanical advantage by using the vaporization of the water powered by the heat of the regular fuel.
And water is easier to find and cheaper than ethanol when it comes time to refil the second tank.
This has been well known for a long time.
The reason it hasn't been built into production engines so far: It requires two tanks of consumables. Run out of one and the engine has to stop, or run in a degraded mode. Auto makers haven't wanted to add that sort of operational complexity due to liability and consumer satisfaction issues.
This "new" idea has the same drawback, only moreso, since the second consumable liquid is less generally available and already highly regulated.
= = = =
On the other hand, we've now got much more flexible computerized control of the engine. With the compression boost provided by a turbo (which can be disabled by software control if the alcohol or water runs out), a car with an empty second-fuel tank can still run while meeting emission requirements and without self-damage. You'd lose 2/3 of your peak power and your MPG would drop. But the car would remain legal, street-legal, and unharmed.
So perhaps it's time to revisit direct cooling-fluid injection, dual-consumable, internal combustion engines.
But if so, unless research shows that ethanol has some BIG advantage over water, using water would have the advantage that you don't need to modify the support infrastructure.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The '07 MINI Cooper'S has a 4 cylinder 1.6 liter direct-injected twin-turbocharged engine - and since most fuel in the US now contains 10% ethanol, I'd say the "experimental" technology these guys are pushing is already out there in at least one production car
As the article notes, direct injection has been around for a while (since the '50s). Turbochargers are older than that. The idea here uses direct injection in a novel way.
. . . just about all modern cars have an anti-knock sensor that can richen the mixture if it detects signs of knocking - but with high octane gasoline - it only very rarely has to actually do that - so the "problem" of knocking isn't really there.
The problem isn't stopping current engines from knocking. The problem is to increase compression ratios or boost of an engine without introducing knocking. Increasing the amount of gas in the mixture only makes your fuel efficiency worse.
The key to this new idea is that the ethanol is injected separately from the regular gas (specifically, during the compression phase). Naturally, you'll need a separate tank of ethanol, which the article claims would need to be replenished about as often as a oil change.
As we know from thermodynamics, matter going through a phase change from liquid to vapor will suck away a lot energy. Ethanol has the nice quality that it will go through a phase change at a lower temperature compared to water.
Thermodynamics also tells us that as pressure increases, so does temperature. In a normal engine, the piston will compress the fuel/air mixture, thus increasing the temperature of the mixture. If the temperature gets too high, the mixture will ignite on its own. This is more likely if your engine has too high of a compression ratio or you're using some kind of boost system (turbo or superchargers). This is why cars with turbos often have intercoolers.
What they're doing here is increasing the compression ratio and/or adding a turbo. You can choose to slap on an intercooler if you wish. As the piston goes through the compression stroke, the fuel/air mixture gets hotter as before, but then some ethanol is injected, which vaporizes, thus cooling the mixture. The mixture is then ignited by a spark plug normally. Brilliant.
Not a typewriter
What did someone overturn Carnot cycle efficiency?
You can always detect hype when they completely disregard the second law of thermo.
Some brilliant scholar once said "In this house, we obey the laws of thermodynamics!"
Knock sensors detect detonation, not pre-ignition. Besides, richening the mixture defeats efficiency. The idea is to run lean without detonation.
Injecting ethanol separately from the gasoline is different than mixing it, and it's nothing new. Oldsmobile made turbocharged cars with alcohol injection 40 years ago and people have been adding it to turbo Buicks for a long time as well.
Direct injection's time will come, but I'd wait at least a decade for the industry to be ready to handle 1000psi gasoline rails.
Electric water and oil pumps are a suckers bet. Don't plan on a long life for that engine.
Water (yes, water) or ethanol injection are already commonly used by tuners to allow them to run at higher compression ratios without preignition. (which is really a step beyond knock -- TFA really doesn't describe the problem accurately).
Once again MIT is trying to claim credit for things others have been using in practice for a long time.
You just proved his point with your link...
That's great...
...if you want to drive a subcompact. What about for those of us who want to drive a midsize car like my Avalanche?
The Kai's Semi-Updated Website Thingy
In the second half of the article they get down to brass tacks. "A vehicle that used this approach would operate around 25 percent more efficiently than a vehicle with a conventional engine."
That sounds a lot less dramatic than "a design that could triple the power of a test engine."
That that is is that that that that is not is not.
the valves are using cams, they are not infinitely variable computer controller by some kinda magic solenoid or motor or whatever. people have talked about doing that sort of thing but the cost, compared to the good old fashioned cam shaft, would be pretty expensive. look in google groups for more info on this.
== "Turbo Direct Injection." Used in volume by VW and others for more than a decade. It is for Diesels, the same thing for gas is called FSI ("Fuel Stratified Injection") or TSI ("Twin/Turbo Charged Stratified Injection".)
Now tell me again why high gas prices are bad for the economy.
thegodmovie.com - watch it
The question that I have is what happens if the direct injection ethanol system should fail or if the tank of ethanol runs dry while the vehicle is in operation? Would it not be difficult and add substantially to the complexity of the engine to detect that the ethanol system has failed and thereby automatically take steps to reduce the compression ratios or else suffer severe knocking?
If this technology is to be widely deployed then it must be able to degrade and fail gracefully without causing damage to the engine. It would also be desirable for the mechanism by which the engine is switched back to regular compression ratios to be highly reliable or else the engine must be designed in such a way that damage cannot occur if the ethanol system fails.
Another interesting question is the effect of more alcohols burning in the engine and producing more water vapors which will serve to foul the oil more quickly than normally occurs in a plain gasoline engine (with minimal ethanol added to the gasoline). The oil filters are designed to handle some water contamination but this type of engine would require a more substantial filter to handle the increased load.
The 2007 Saturn Sky Redline also has a DI turbocharged engine, and it does manage to crank 260 HP out of 2.0 liters, making it GM's highest-output engine for its size ever, but it still gets pitiful fuel economy (some reviewers got 14.3 MPG average during their test). The 6.0 L 400 HP standard corvette engine, which is naturally-aspirated and pushrod-controlled, has only slightly inferior fuel economy.
As I read your post it occured to me, why just ethanol? I was thinking acetone.
Why not any organic solvent that easily vaporizes? Ever worked in a chem lab, acetone vaporizes and leaves the glassware (and your skin) COLD!
Google acetone in gasoline.
Preignition is when the fuel/air charge ignites at the point of lowest compression, and then the engine has to compress this hot, expanded gas. This is how holes get burned in pistons. Knock is detonation, where the fuel/air charge does not burn in a controlled flame front, i.e. it suddenly detonates. It requires that timing advance be backed down a bit.
There are only 10 kinds of people in this world... those who understand binary and those who don't
The newest Audi/VW 2.0T motor, found in at least the A3 (plus A4 now?), GTI, and Jetta, is a direct-injected turbo motor. A simple chip upgrade puts it at 260HP for 2 litres, and is basically torque limited by the stock transmissions. Get manual if you really want to tune on that platform.
The article has some interesting technology but most engines still aren't making decent use of the existing technologies. The US seems to lag in engine technology, but it's not even just down to US manufacturers. Just picking a car I would consider buying - the Honda S2000 - here in the UK, it uses a 2 litre engine, while the US model uses a bigger 2.2 litre that produces less power, much less torque, has a much lower redline, and worse fuel consumption to top it off. I'm not singling out the US here though, it's only a little behind.
The S2000's 2 litre engine is regarded as one of the best 4 cylinder engines around. It develops more power (240bhp) than a typical 3 litre V6 and being substantially lighter than a 4 litre V8 means even they don't have much of an advantage. I'd love to see that sort of engine in some more practical cars. The problem is it's easier to play the numbers game and put in the 3 litre V6.
How the heck is that new ?
WTF do they think "TDI" stands for ? (hint - something to do with Turbo and Direct and Injection perhaps ?)
Oh, wait it's MIT, they're American - that place where fleet average fuel economy is currently going DOWN and heading for less than half that of the EU and Japan. Probably they think the D stands for Diesel (wrong), and every good US auto maker knows you can't build a diesel vehicle with anything less than 18 wheels...
On the petrol side, seems like they missed the engine-of-the-year awards (for a couple of years) too: http://www.ukintpress.com/engineoftheyear/winners
These folks really do need to get out more, and then come up with something new - claiming that combining turbo and direct injection is new is just laughable.
Ethanol's intake temperature benefits are not new knowledge. Direct injection isn't required for a benefit; I suppose it's possible they're found something new but I doubt it; probably just an ethanol hyping professor. I'd perk up if he had any amazing efficiency or hp/cubic inch numbers to back up his claims.
Well, for the record, completely mechanical thermostats have been a part of engine cooling systems since... well, probably nearly as long as enginges have been around. The radiator in a car is designed in about the worst-case scenario. The thermostat valve is definitely much wider while driving in Texas in the summer than Maine in the winter, but the engine temp would remain the same. If the thermostat wasn't there, my engine might never get warm in the winter (esp. consider the size of the radiator exposure on my car).
SIG: HUP
+5, Funny.
thegodmovie.com - watch it
Other people have different things to say about Cobasys:
And this, which killed the electric RAV4:There's plenty more, just perform the search suggested at the first link.
It appears likely that the advances in Li-ion and carbon-backed lead-acid will make it far more difficult to keep the next round of batteries out of vehicles. Regardless, the delay in availability of mass-market PHEV's and EV's has meant many billions or tens of billions of dollars in additional revenue for the oil companies and oil exporting nations. (The current administration shares responsibility for e.g. terminating the Partnership for a New Generation of Vehicles, which would have delivered 80-MPG sedans about.... now.)
The take-home lesson? Don't believe everything you read.
Sustainability and energy independence essay
what does that say about the size of your hard disk?
Just a MIT professor trolling for grant money, why is this news?
B.t.w., many (most) car engines now running in US could be tweaked to increase their efficiency. Unfortunately, it looks like the efficiency peak and the emissions dip do not coincide and the car makers design their engines to lower the emissions (thus running the engine at a lower efficiency than possible).
B.t.w., a higher compression ratio obviously improves the cycle's yield, that's common knowledge. Unfortunately, unless the engine is fed pure oxygen, the NOx residues increase dramatically.
Triple the power doesn't mean triple the efficiency, if "antiknock" means more fuel is burned. 25% more efficient is more like it. Fuelcells are typically 50% fuel efficient, compared with 40% maximum (to date) internal combustion. That's about a 25% efficiency increase, it's already here, and it's just getting started. Plus the drastically reduced pollution (especially Greenhouse pollution) means huge energy efficiency at the end of the cycle, when climate disasters are avoided. Meanwhile fuelcell efficiency is just getting started, racing towards 80% (over triple typical internal combustion efficiency) and beyond.
So while this advance might be good for the market that's not ready for fuelcells, the fuelcells still look better. But at least we've got scientists and engineers working on fuel efficiency, and not just ways to squander the remaining fuel for combustion engines. That's a big change in efficiency in itself.
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make install -not war
The benefit of ethanol isn't that it's being burned in concert with gasoline, it's that it can be added to the cylinder to combat preignition. You're also incorrect on how ECMs prevent knock damage. When the ECM senses knock (via the knock sensor) it will retard the timing until the knocking goes away. Adding more fuel _might_ help with knock as it will reduce the overall temperature of the burned mixture but that's counterproductive in that it negatively impacts fuel economy and emissions. Computer controlled intake and exhaust valves aren't exactly new -- the technology is known as "variable valve timing" and has been showing up in production automobiles since the 80s (I'll grant that computer controlled, infinite profile timing is more recent, but it still dates back to ~ 2000). Call me when the MINI shows up with computer controlled pnuematic or electric valves ;)
I'm not sure their claim about this being a better solution than hybrids is justfied. Looking at the Honda Civic and Toyota Camry, the Hybrid versions offer approx. 45% better fuel efficiency, much higher than the 25% quoted in the article for this technology.
Additionally, this technology does not eliminate idling (especially on ignition with a cold and poorly-performing catalytic convertor) which is one of the things about hybrids that gets them a high air air pollution rating (AT-PZEV from the CA Air Resources Board).
Still, because of the low cost this technology might be a great benefit to large cars which are so expensive already, even in addition to hybrid systems.
I just found the box to change my sig. Um.... [timeless witticism].
So producing hundreds of thousands of tons of NiMH or LiON batteries for cars is better for the planet than buying a 40mpg gasoline vehicle...
I've got some new crack-vitamins for you!
From the article:
The MIT researchers focused on a key property of ethanol: when it vaporizes, it has a pronounced cooling effect, much like rubbing alcohol evaporating from skin. Increased turbocharging and cylinder compression raise the temperature in the cylinder, which is why they lead to knock. But Cohn and his colleagues found that if ethanol is introduced into the combustion chamber at just the right moment through the relatively new technology of direct injection, it keeps the temperature down, preventing spontaneous combustion. Similar approaches, some of which used water to cool the cylinder, had been tried before. But the combination of direct injection and ethanol, Cohn says, had much more dramatic results.
Midsize. Riiiiiight.
Switch back to Slashdot's D1 system.
...like this truck.
http://www.backcountryjournal.com/21742.jpg
And it was much better than my compact Maxima.
The Kai's Semi-Updated Website Thingy
I imagine it's probably because ethanol is a renewable fuel that we have tons of and actually contributes to the combustion with less emissions.
"I have never let my schooling interfere with my education." - Mark Twain
A google search for "alcohol injection" will yield hundreds of his, like this one:
c _alcohol_injection.html
http://www.rjcracing.com/SMC_Alcohol_Injection/sm
And as for "fancy computer controls to control knock" it's called a "knock sensor" and "electronic ignition." My 1990 eagle talon tsi had it, and it was not new then.
This is why MIT researchers should get out of their labs once in a while.
Lots of sites about that give some history on it. Here's one off the top of Google search:
http://www.dieselsite.com/index.asp?PageAction=VI
and a lift of what it has to say: A brief history:
Water injection was evaluated scientifically in the 1930's by H. Ricardo who demonstrated that one can basically double the power output of an engine using water/methanol. The first widespread use was during WWII on supercharged and turbocharged aircraft. In 1942, the German Luftwaffe increased the horsepower of the Focke-Wulf 190D-9 fighter aircraft from 1776HP to 2240HP using 50/50% water/methanol injection. The allies soon followed by fitting the P51 Mustang and other high performance aircraft with water/methanol injection. Following the war, the turboprop aircraft industry used water/methanol injection and called it the "automatic power reserve system (APR)" for use in hot or high altitude take off. It surfaced again in the 60's when GM used a system on the OEM turbo Corvair. It was used effectively in Formula 1 before being banned for adding too much power. Bombadier's E-tech outboard engines (no link - horror flash site) use computer timed injection to control charge and lubrication to get greater efficiency and cleanliness from 2-stroke engines.
Again I am not sure which measures of efficiency are being spoken of here, but even a couple of percent reduction of fuel burnt would mean astronomical savings in money, easing of political pressure and of course conserving the resource itself.
hmmm, I always thought that lower demand = lower prices.
We are all just people.
Interesting ideas are coming from Volkswagen, who are developing prototypes of their "CCS" engine technology. It's described as something halfway between a diesel and a petrol engine, with the fundamental principle being spontaneous and homogenous combustion of the fuel. Extensive resuse of exhaust gases is employed to help prevent pre-ignition. These engines use the common rail direct injection systems from VW's TDI engines, and are having fuels designed for them, one based off natural gas and called "SynFuel", the other from biomass, called "SunFuel". Both are, according to Volkswagen, free of sulphur and aromatic compounds, which greatly reduces emissions.
d =10016 for more info.
See here http://media.vw.com/article_display.cfm?article_i
it's practically nonexistant outside of the US, Brazil, and Sweden. That means you can't take road trips,
Oh no, no more road trips to Sweden?!? You can find ethanol in every hardware store in the US and Canada. It's call denatured alcohol, it's in the paint supplies isle.
We are all just people.
Next time, please try reading the article
Other than choice of fuel and the retention of a spark plug, how is this not the same as a turbocharged diesel?
The truth shall set you free!
The market for high fuel efficiency is with some of the hybrid cars (can't say whether they hybrid Highlander, Escape, and even Camry are really providing such high gas mileage, and the hybrid Accord and certainly the hybrid version of the ES300 seem to be more of a performance market) -- there is also a small fuel efficiency market with the VW direct-injection Diesels. Beyond that, I don't see anyone marketing fuel efficiency, even at today's high gas prices.
Go over to www.thetruthaboutcars.com, and those dudes have the odd article complaining that there are no advances in fuel economy, but they rag on any car with a 0-60 time of 8 seconds or longer. There was this thing on cable TV covering the auto show where there is a Mazda 3 (otherwise a small, practical car with somewhat sporty handling and good ergonomics and space efficiency) being equiped with a 260 HP 2 litre direct-injection turbo motor.
I imagine with that motor you have a sporty car with comparable gas mileage to say a V6 Camry, and maybe a souped-up Mazda 3 with that motor is a more ecological choice for someone who wants a sporty car than a Mustang GT with a V8. On the other hand, couldn't they equip a Mazda 3 with a 1 litre 130 HP motor using that same technology, and wouldn't that car get a lot better gas mileage yet have perfectly workable levels of acceleration? I know things don't scale -- the 1 litre engine doesn't get twice the mileage of a 2 litre engine on account that not all the drag in a vehicle is engine friction.
People keep acting like the knock sensor is the only possible way to prevent a shortage of ethanol from causing problems. Think about it; there's got a tank of ethanol that's feeding this system. If my car can signal me when my windshield washer fluid is low, I think it can detect when this tank goes empty, too. All this takes is a level sensor (or pressure sensor) hooked up to the control unit. The knock sensor should be a final backup for detecting a problem, not the first line of defense...
If the ethanol fails to get to the injectors because of some other problem not related to a shortage - well, there's a lot that can go wrong in modern engines. This isn't really any likely to fail than any of the other high pressure delivery systems already supporting engines.
Use a higher-octane fuel, advance the timing, and use a block/head that sheds heat more quickly.
OK, now I've read TFA. It looks like they're injecting ethanol not just for the octane, but for cooling. Previous far-out turbocharging systems have injected water for cooling, ethanol is a step over that.
The ideas, though, aren't really new. Back in WW2, before the USA entered the war, the German planes significantly out-performed the British planes. Suddenly, baffled German pilots found that the British planes were pulling away, climbing and flying faster. They knew that they hadn't had new engines installed, it wasn't until they found a downed plane that they found the source: The USA, while not technically entered into the war, had been supplying fuel to Britain which had an octane rating about 40 points higher - allowing more compression and power without the knock.
Blending fuels isn't exactly new, either - top-fuel dragsters run about 97%-98% nitromethane, with a small amount of racing fuel added to keep things from getting too rough. In any event, now that I'm done shooting down their claims about being so revolutionary, I think that they should keep up the good work. Any improvements in this area are very good ones for all of us.
Oh, you're not stuck, you're just unable to let go of the onion rings.
I work in a physics lab and use acetone all the time, and it's true that acetone "feels" even cooler than ethanol as it evaporates. By the way, I wouldn't handle pure acetone with bare hands!
Ethanol is probably more practical than acetone since it's cheap,it's already produced in huge quantities and distributed to fueling stations, and it's less toxic.
My bicyles
Direct injection's time will come, but I'd wait at least a decade for the industry to be ready to handle 1000psi gasoline rails.
Common rail diesel engines use rail pressures up to 1600 bar (23,200 psi), and normal hydraulic car brake systems (which the automakers have been reliably making for a long time now) can easily exceed 1000 psi on a regular basis. I don't see why 1000 psi for any other fluid system would be a problem.
Putting moderation advice in your
I only have a 10 gallon tank, and it's cosing me almost $30 a fill up. I'd be saving $7.50/fill, ~$780/year. Somebody with a truck or SUV would only save more.
You tell somebody that it'll save them $1k a year in fuel and many will go through the bother of keeping it filled. Or just let the oil change guy top it off along with the other fluids.
I don't read AC A human right
The difference is that spray-guided direct-injection is here, and available for passenger cars. That wasn't true 60 years ago, or even 20.
You're probably right about the auto companies (I know them, from the inside), but they don't have a choice any more and they seem to realize it.
Sustainability and energy independence essay
Not that I'd expect you to admit this, because you're a troll.
Sustainability and energy independence essay
The US has very strict diesel emissions standards, that is why we have so few diesel powered autos here, although diesel trucks, from pickup sized on up, are common. This year lower sulphur diesel is being mandated and there will be more entries. Most european diesels can't pass emissions here yet, ie, you are worse polluters with that, but because your fuel is so much more expensive, you put up with it.
So it isn't that we are ignorant of diesels-the US has a very robust past history of ICE powered everything, thankyou very much, we just took to gasoline more for autos, that's all. And don't forget, we were a huge oil producing nation for a long time, even exported a lot, just starting in the 70s we were forced to finally really import a lot more. And as such, when the crude gets refined, we had the gasoline, so we used it. What were we supposed to do, throw it away?? You get a variety of fuels from crude, we used all of it in some form or another. Gasoline, diesel, kerosene (think jet fuel then)-all comes from the same distillation and cracking. so-gas for cars, diesel for trucks and trains and industrial equipment, kero for planes. makes sense, wastes nothing.
Most of our other equipment besides light cars is all diesel powered, except for stuff used inside buildings or mines, which are usually propane or electric battery powered. Myself, today, only used a smidgen of gasoline in a mower and trimmer (probably a quart or less), the rest was diesel in two different tractors. In fact, I think I personally drive more miles on a diesel tractor then I do driving gasoline powered cars any more.
And sorry about your excessive fuel costs, but how again is that "ignorant americans" fault? If you guys are so much smarter, why do you even need "modern diesels", shouldn't you be running on pure hydrogen by now, or pure electric? Go ahead, show us your smarts! If it is really that much better, we'll buy it from you. If you can make your diesels all pass advanced emissions standards, then by all means, export them here, pass the tests, you'll sell them. People here want good mileage PLUS good performance PLUS good range, all of the above. We need performance and range first though, because we are a big nation, we travel a lot, we haul a lot of stuff, etc. Make the vehicles realistic to fit our nation, and they will sell. Even the japanese makers finally got hip and all produce real sized pickups now, because we need them that size for a lot of purposes.
The US is never going to be "your" nation, so don't think it will be-it just isn't going to happen, apples and oranges. Celebrate the differences, it would be beyond boring if we were all the same now wouldn't it?
I agree with you that asking consumers to keep up with two fuel tanks is a big negative. I designed an engine process that re-uses the water for a very long time (engine life) > http://www.newpath4.com/enginewow.htm with extra links on > http://www.newpath4.com/imitationenergy.htm . It is essentially a "climate engine" that combines highly compressed liquid air with the water being pre-flashed into steam.
The air is also recycled, recompressed endlessly through compressors that replace the car springs and shocks. Neither requires refueling & neither requires a fuel tank because the lines from cylinder exit around to cylinder injection constitutes the storage tanks. Much as this looks like perpetual motion it is not because the gravity-inertia being used to recompress the air is an "outside energy source", a definite disqualification for perp.
Since this "imitation fuel" combo is pre-processed before cylinder injection the returning piston is not losing power to recompress the next fuel mixture like a combustion engine, significantly reducing combustion engine efficiency to 25%. So while the steam + air may not produce an equal horsepower of a Hemi rig it gains a 400% effective hp boost. Being running at a balanced temperature, such an engine does not need a radiator, further reducing hp requirements.
But you should give these other guys some credit. They're trying.
Industrial Age 2 + How-to Stop Malignant Cancers.
This is old news. My 1981 Callaway BMW comes with a water injection system. The thing is you don't put water in it you put ethyl alcohol. Why? Well its water based which created steam and compression and then the Ethyl burns cooler preventing my pistons from melting. What is so different about this?
OMG Ponies!!! with Glitter!!!! I miss Pink
I agree though that cooling the cylinder with ethanol vapourization is an important innovation, but it would seem to be a complex addition to an engine. If I'm not mistaken, to take advantage of this, you would need to have a separate, parallel injection system for the ethanol rather than a blended fuel (which we already have). If this is the case, then an engine would need to be substantially revised to allow for dual injectors, and I would image the engine management would have to become much more sophisticated ensure that the ratio of gasoline to ethanol was appropriate throughout the combustion chamber. I would hate to find out what would happen should this system fail, starving the engine of ethanol, presumably causing massive knock issues.
Yay, wow! Let's spend all our energy research money on building better ways to burn fuel. Increasing fuel efficiency is good, but we're still burning fuel. Can't this research effort be put into something non-polluting?
Actually, you're wrong. You'll notice that people driving older trucks put cardboard in front of their rad in the winter. This is because, as you suggested, the motor never gets a chance to warm up in the winter. I have a 86 Ford that is like this. The water pump is driven directly from the main pulley system. So long as the motor is turning, coolant is circulating through the radiator.
What a lot of modern cars do is that they circulate the coolant all the time. To prevent over cooling, the radiator fan is only turned on when it is required (via a heat sensor). This is likely how your car works. Seeing this for the first time (in 1990) was a big deal as previous vehicles simply turned the fan all the time. (Please note that I was a kid in 1990 - it was obviously in existence before that.)
Willywhy would premature combustion still be a problem in a direct-injection engine? It should be possible to inject the fuel when it is needed, and not before. Or would that lead to timing problems?
If you can define what mature combustion is, your engine will be very satisfied. Is it true that Honda's charge shaping hits her G-spot? Lube and timing are critical, especially on start up. Chitty-chitty bang-bang, we love you.
An actual answer to your question can be found in the above link. You need the correct distribution of fuel for proper operation and might not be able to get that with direct injection and still avoid pre-ignition.
Friends don't help friends install M$ junk.
I'll echo the hundred other people here. I drive a VW TDI, which means Turbo Direct Inject. It's pretty old-hat for diesel cars. For gasoline engines, though, this is certainly something new.
TFA is pretty bad IMHO. First they say the new engine would have triple the efficiency. Later they say a 25% increase in efficiency. What they propose, is to start using pressures inside the combustion chamber similar to that found in a diesel motor (most gas cars are ~10:1 compression, diesels are ~20:1). They don't talk about NOx, oxides of nitrogen, that tend to form when fuel is combusted at higher pressures of O2, though. Will modern catalytic converters be enough to deal with the increased NOx? Catalytic converters are probably the biggest bane for diesels, because the fuel has more sulfur than gasoline, and sulfur kills the magic catalyst material by bonding to it and making it not respond to nitrogen anymore. Ethanol probably doesn't have that problem, but the volume of NOx coming out the tailpipe will need some dealing with, the unit injectors for the ethanol will be expensive (you'll need fuel injectors + unit injectors or a common rail system, instead of just unit injectors/common rail on a modern diesel), and all for not a lot of gain in efficiency.
It seems like a lot of research will have to be done to make gasoline cars as efficient as a modern diesel, and then even more work will have to be done to clean it up. Yikes. I'll stick with my Jetta, thankyouverymuch.
Reid
The Right Reverend K. Reid Wightman,
Isn't this something Mitsubishi are working on with their GDI (Gasoline Direct Injection)engine?c tion
http://en.wikipedia.org/wiki/Gasoline_direct_inje
For something even more novel, see http://www.prautotype.nl/ (sorry, only Dutch) for an engine that can use a different compression for compression and exhaust stroke and can even change its compression dynamically whilst running.
Now all they need to do is add pre-atom smashing, so when the water from the garden hose gets to the intake manifold, it is changed to two pieces of hydrogen, and disgard the one piece of oxygen, then send the two hydrogens to the pre-ignition thing-a-ma-bober and boom, Bush's filthy oil war was all for naught.
Where did they find this word? What's preexisting? You can use "Existing" in exactly the same place and get the same meaning, what are they trying to achieve by using this word? So now my cellphone is preexisting too?
You need to put batteries into that equation somewhere because fuel cells are slow to start up. Battery production and disposal SUCKS for the environment.
+++ATH0
Actually, dickhead, it is you who is wrong. Engines have had thermostats from the start, You came to that conclusion from seeing clapped out old cars with the wrong thermostat, too big a radiator or most likely, thermostat siezed with scale. As for electric thermo-fans, they are used because they are more efficient than pulley fans which run to slow at idle and are pointless at highway speed.
Whatever.
REAL "Internal Combution" increases come from drowning a jalapeno taco from the BurritoMobile across the street in Tabasco sauce.
Granted, you won't get very many miles per gallon out of it before you have to stop.....
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....
"Cohn and his colleagues have created a design that they believe could triple the power of a test engine"
is that all?
this has been done years ago on a buick grand national. they were late 80's v6, and turbo'd. by adding efi, and some other tricks, quite a few people have gotten over 1200 hp out of these motors, and not just in a lab, but on a streel legal, drive-able car.
Ethanol is more volatile than diesel I believe and might compression ignite more readily than the diesel which would require it to be injected very late after TDC in turn negating the cooling effect it would have to the chamber. But it would work as you said it would if some other substance exists that would have a higher octane than the diesel.
And no, I couldn't give a shit what my karma is.
FYI my 1993 MR2 had an electric power-steering pump. I also doubt anyone is shutting down the OIL pump at any time.
Is to remove the one of the biggest obstruction's to making more power...the valve. http://www.coatesengine.com/ I still don't know why every car manufacturer hasn't implemented rotary valves, it's got to be politics holding it down. Wayyy more power, better MPG, less moving parts, oil changes every 50,000 miles, it's ridiculous.
German aircraft engines in world war 2 had direct fuel injection and also injected MW50 (50% methanol 50% water) for maximum power.
Commenting to cancel a mistaken mod. I have no idea who I modded Troll, but didn't mean to do it.
Again I am not sure which measures of efficiency are being spoken of here, but even a couple of percent reduction of fuel burnt would mean astronomical savings in money, easing of political pressure and of course conserving the resource itself.
Long term, that's what it means. Short term, it means (from the article) a $1000-$1500 increase in engine production costs, plus additional expenses in safety measures, safety testing, and the development of maintenance manuals and training for mechanics.
Automakers are in business to make a profit. This tech will take years of work to go into production, and a few more years before it is profitable. I predict it never makes it to production, because there is an environmental case but not an economic one.
In addition to the racing technologies that others have mentioned, there's a whole lot more common example of this existing technology. Saab has been selling cars to normal folks like you and me for over 20 years with this kind of technology right from the factory. They started out using a simple(ish) analog circuit to control the turbo waste gate valve based on an engine knock sensor. Too much knock, step down the boost (by bleeding some off through the bypass valve) until the knocking goes away. It allows the tuner to crank the boost up significantly (as long as the engine seals hold) and let the circuit sort out how much boost the engine can run on, given the fuel supplied. Saab engineers have made their careers on extracting lots of HP and torque from 2.o and 2.3 liter 4 cylinder engines by judicous application of turbos.
Need a simple, easy to use data tier generator? http://www.gryphinsoftware.com/
In RL, would your name happen to be A.Square and your home area Flatland? Hills and mountains are not imaginary things you see on your TV set. Lots of hills outside where you live, and to get from home to the water, one has to drag one's trailer over those hills.
Tech Public Policy stuff
This *IS* new, in the sense that they are not proposing add-ons to existing vehicles at all! Rather, they want to design the engine around this technology in order to get higher compression ratios than are currently available. Saying that this is old just because there are add-ons for existing engines are missing the whole point of the article. Existing engines do not have the compression ratios they are talking about. Having said that, though... am I the only one who noticed that the statements "triple the power of a test engine", and "25% more horsepower", differ by more than an order of magnitude?
There are lots of anti-detonation methods around. My favourite is Honda's CVCC (1970s) and CVCC-II/Combax (early 80s). These divide the combustion chamber into two areas. A small area has a rich mixture and the spark plug, and is separated from the rest of the combustion chamber by a perforated panel. The main combustion chamber can be run much leaner, as the flame front passes smoothly into this area through the panel. This slows the burn process and effectively increases the octane rating of the fuel - so, no detonation. The benefits are considerable - cleaner burning, these engines were able to meet emissions standards with no catalytic converter. Plus, the Combax Turbo was able to produce huge amounts of power, without the detonation problems that normally plague turbocharged engines, and with much less stress on the engine. It's a very clever system, and I thought it was worth mentioning here as it's a very workable way of reducing detonation without having to go to the trouble of using additives. f.
http://auto.howstuffworks.com/cooling-system8.htm I strongly suspect that the cardboard factor has to do with raw airflow over the engine since the opening on large trucks is so big. I'm strongly considering cardboarding mine next year as well, since it suffers a similar problem of taking a very long time to warm in winter (almost the whole facia, axle to hood between the headlights is exposed for ventilation).
SIG: HUP
Actually as a kid we had a '37 Morris Minor which had no water pump or thermostat, just a big radiator with blinds in front for winter.
Coolant circulated by convection.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
I believe that on most cars, the water pump is driven continuously by the engine - whether it's needed or not. What the mechanical thermostat does is to allow the output of the pump to go through the radiator or simply to circulate around the engine block and directly back to the pump. So when the engine is cold, no water flows through the radiator - but the water pump is still pumping at full speed. As soon as you get up to temperature, the thermostat opens, the water goes through the radiator and (all being well) the engine temperature immediately stabilises at whatever temperature your thermostat was built to set.
The radiator fan is also turned on and off with an electrical thermostat - you don't need the fan on unless the radiator is failing to cool the water sufficiently unaided - but that's not to regulate engine temperature - that's to save energy by not running the fan unnecessarily.
Some people react to a chronically overheating car by completely removing the thermostat which allows the water to flow around the radiator all the time - and removes an obstruction to the water flow. However, this can be dangerous. On an older car that I own (a '63 Mini as it happens), removing the thermostat also removes turbulance from the water stream which causes a 'stagnant' area where water no longer flows - this results in a hot-spot building up on the sides of two of the cylinders which can wreck the engine in pretty short order!
If you did that on one of these trucks - then you might well have problems in cold weather of the engine never reaching it's desired operating temperature. That's bad for gas milage - but shouldn't be all that serious otherwise.
www.sjbaker.org
A turbocharged diesel may use direct injection, such as in the VW TDI engines, but it uses direct injection for the diesel fuel. The system in the article uses direct injection only for the pure ethanol which is injected seperately, and out of phase, from the main fuel. The pure ethanol isn't, primarily, meant to be burned. It serves to cool the cylinder through evaporative cooling. If it were injected with the fuel (as is the case with 10% ethanol mixed fuel from a gas station, it would just be burned with the rest of the fuel and wouldn't cause any cooling effect. This is also why the pure ethanol has to be stored in a seperate reservoir. This may end up being the achilles heel of the design as similar systems have been introduced to the market in the past (the 60s) and failed because people were too lazy/annoyed to bother keeping the seperate reservoir filled.
-GameMaster
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