Posted on 04/29/2008 7:38:08 AM PDT by Red Badger
Researchers in the UK have developed a new kind of engine. It could be called a hybrid, but what it combines is not two power sources but rather two mode of operation: 2-stroke and 4-stroke. The goal is to be able to significantly downsize the engine and get the fuel economy benefits of smaller displacement, but to be able to switch seamlessly to 2-stroke mode when more power is required at high loads and low speeds.
The prototype (seen above) is a modified 2.1-liter V6. After tests at the University of Brighton, it has been found to produced performances similar to a 3 to 4-liter engine, with fuel savings of 27% and emissions reduced by about the same amount.
The next goal of the researchers is to incorporate the prototype engine in a vehicle.
It isn't the first time that this kind of hybrid 2/4-stroke engine design has been looked at, but in the 80s and 90s the technology simply wasn't advanced enough. "According to Ricardo, the only reason the company is able to make a viable system now is because of the software that controls the gas exchange and engine modes."
If all goes well and nothing major holds back the adoption of such a technology, it could make a big difference in the next few years. Of course, the goal is to move away from fossil fuels, but realistically, that will take a while and in the meantime a 30% improvement in efficiency would be welcome (trucks with 2-liter engines, cars with 1-liter engines). No reason why these couldn't run on cellulosic ethanol...
![](http://images.google.com/images?q=tbn:R8sR7daexSBGmM:www.ted-kyte.com/3D/Pictures/Spark%2520Plug.jpg";)
Rest In Peace, old friend, your work is finished.....
If you want ON or OFF the DIESEL ”KnOcK” LIST just FReepmail me.....
This is a fairly HIGH VOLUME ping list on some days.....
2-4 Stroke engine Ping!.........
I drove a 3-liter Geo once. Someone needs to feed that squirrel!
3 Liter or 3 cylinder? 3 liters is a big engine for a Geo!................
3 liters is 183 cubic inches! THAT GEO WOULD fly!.............
I think it’s a 1.3 liter 3 cylinder, or some such.
I test drove a 5 cylinder Volvo over the weekend........Nice!..........
Sounds good.
I don’t believe it is diesel, why the spark plugs rip?
I’ve got a 6 cyl BMW...I win
Greater valve overlap and exhaust gas scavenging in the two stroke mode? Iffen remember rightly, Aussie Ford/Orbital’s wet-sump, TDI-ish two strokes of the mid-90s were a very near miss, but were blocked by their emissions.
I drove one of those over the weekend, too! Very nice car........Trying to fit it into the budget somehow, someway........
I didn’t have time to remove the pic........
I drove a friend’s diesel Dodge Ram 4wd on a long trip. Got 15-18 mpg pulling a trailer........Now I’m jealous.........
I can only badmouth the 3 cylinders I’ve driven: Geo and Precis. The Precis in particular was a POS. The engine was so weak even the AC didn’t work. And that’s unacceptable in Texas.
Used to be, I couldn’t even stand 4 cylinders. Now I’ve made myself drive one from time to time, but I still prefer a V6.
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