Posted on 10/25/2012 9:35:49 AM PDT by JerseyanExile
As automakers augment the reciprocating piston engine with hybrid systems and improved accessories, independent inventors are busily working to make huge improvements to the basic efficiency of the internal combustion engine. Novel designs are popping up at engineering expos everywhere, and the newest comes from Bloomfield, Conn.-based LiquidPiston. Its X1 engine is a simple machine with just three moving parts and thirteen major components, but it aims to raise thermal efficiency from the 20 percent of a normal gas engine to more than 50 percent, with drastic reductions in weight and size. How? By wasting much less energy during the course of an combustion cycle.
Up to 80 percent of the energy in fossil fuels is thrown away normal engines through the heat and pressure of exhaust, or dumped to the atmosphere through the radiator. LiquidPiston's design attempt to capture all of that waste within a tiny package. "We stretched the performance curves in every direction to get much higher efficiency," said Alec Shkolnik, President and CEO of LiquidPiston, "We took the best parts of many different thermal cycles and combined them." The design is theoretically capable of 75 percent thermal efficiency, but the group is targeting 57 percent in real world applications, still a huge jump.
The basic idea is similar to a Wankel rotary, but turned on its head. Where the rotor holds the seals in a normal Wankel, the housing does that job in the X1 engine. This allows significant reduction in oil consumption over a regular rotary motor. Other enhancements include direct injection, a high compression ratio at 18:1, and a dramatic change to the geometry of the combustion chamber, which maintains a constant volume during ignition. This change means the air-fuel mixture auto-ignites like a diesel, and can be burned much longer than normal. The result is a more complete combustion ending in low emissions and very high chamber pressures. This high pressure is allowed to act on the rotor until it reaches nearly atmospheric pressures, so almost all the available energy is extracted before the exhaust is physically pushed out. Again, this is different than a normal internal combustion engine, which releases very energetic, high-pressure exhaust gas.
Some other slick features: Since the engine is designed to convert so much more heat energy into mechanical force, less heat has to be removed from the block, so there's actually no water cooling system. In cases where the engine is under load and needs to cool down, it can skip an fuel injection event and just suck in cool air, which is then heated by the block and gets exhausted. Another option is to inject water into the combustion chamber. This has three effects: cooling the engine, reducing NOx emissions, and converting some of the water to steam, which increases power.
The compact design of LiquidPiston's lab engine currently tips the scales at 80 lbs for the 40-hp model. It would weigh less than 50 lbs in production, the company claims, far less than a comparable 40-hp diesel that would tip the scale at around 400 lbs. LiquidPiston's current aim is to continue developing the engine with an eye on the sub-100 hp market—compressors, hybrid range-extenders, military applications, boat engines—and license the intellectual property to manufacturing customers. We love seeing plucky inventors like these to completely rethinking the gasoline engine.
I took me about a day and a half returning home from California which included stops and wandering through the painted desert/petrified forest in Arizona along with a stop for a shower and cooking dinner at a state park in Oklahoma.
On our trip out west, we went through Montana at an average speed a little over 100 mph and a high speed of 120 mph. The rotary was actually more fuel efficient the faster one drove.
I remember one time on the Eisenhower expressway in Chicago when I went from a dead stop to 70 mph in FIRST gear alone and the car was very willing to go much faster. It had a constant feeling of tremendous acceleration during that event.
That should be “Disneyland in California”, sorry about the typo, Dan
It’s a shame they couldn’t get those engines to last longer.
(I’m glad my friend didn’t try to get that RX2 up to 120 though!)
I read that a new Mazda RX 8 burns through a quart of oil every 500 miles. A lot of people are afraid to buy a new car that burns oil like that.
My 1979 “aspirated” RX-7 was a blast. I gave it away when I left Chandler. Just a thought to share.
Thanks JerseyanExile.
As I recall, there's a reason the Wankel rotaries are popular in home-made small aircraft: when they go out they tend to be a gradual loss of function.
The Wankel did make it to market, but it took years and almost bankrupted Mazda, who were finally able to get the seal technology it required.
The Wankel design was revolutionary, but seal technology was not advanced enough for production... not until a junkyard’s worth of experimentation by Mazda and false starts with crappy cars MX2 & 3 I think it was...
Finally, by the RX7, they got it right.
This guy should pop one of these into his own car and drive it himself. I would!
Fingers crossed...
Admit it. You just wanna see this motor in a bike. ;-)
I always wanted to run the Norton Wankel bike. A smooth straight torque curve can be fun.
Maybe they finally got it "right" but it's still a commercial failure.
Thanks for the post & the ping, respectively! Really cool!
If it starts with a vowel, (a,e,i,o,u), use an. An owl.
It'll sound right 99% of the time. I read it aloud in my head before I hit "Post." If it doesn't sound right, I'll double back and try to find where it clangs like a dropped anvil.
It was like my idea of using a pump jet, like on a jet ski to drive a sailboat. Without the prop, it would cut down the drag, and eliminate the torque effect at the stern when backing during docking maneuvers... With the explosion of jet skies, the technology was there.
Over and above, you could shift the power pack farther forward, since the drive shaft length and angle was no longer a limiting factor, to improve the boat's center of gravity, center of buoyancy and the CL of thrust on the rudder, as well as engine cooling.
But, what do I know?
Had an ad for this pop up on Facebook. It’s been over 10 years since this thread was posted and the company is still looking for investors?! Seems like they would be taking over the world by now.
Just saying...
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