A dubious alternate engine idea
My Nissan pal Bruce sent this revolutionary engine design. It is revolutionary with the speed it can toss away investor money. Like me, Bruce went to GMI, and he had to take the Carnot cycle in thermodynamics class, as well as the Diesel cycle. Unfortunately, there is no “Something-for-nothing” cycle.
Sigh– where to start? This isn’t really an opposed-piston diesel engine like the Fairbanks-Morse marine engine mentioned in the comments. They have taken the port-valve principle to absurdity and tried to move power from the opposing piston-valve mechanism to a single crankshaft. It looks like you should get double the power, since there is pressure on two pistons per cylinder being transmitted to the crank, but the power is an integral of the pressure pulse over time, and since the volume of this cylinder opens up twice as fast, you end up where you started, half the average pressure operating on twice the surface area, plus all the added friction and mechanical losses. Look up BMEP on the Internet for some insights.
For people pursuing bad ideas for decades, see Moller’s Air Car fiasco. My pal Bob Dible literally took 40 seconds on the back of an envelope to show me why the Air Car was stupid. It has to be loud and it has to get really poor fuel consumption. There are millions of semi-engineers that don’t do the early feasibility work and convince themselves they don’t have a breakthrough. This engine is just another Air Car.
This motor will not pass smog. Not as a diesel, not as a gasoline, not as a hybrid. Getting combustion heat out of one piston is hard enough, some companies spray oil on the underside of the piston. This guy has two pistons per cylinder. He must have Harry Ricardo doing his oil-control, to keep oil out of the intake and exhaust flows.
Here is what is going on. Any two-stroke motor will have much better specific output (hp/lb). They will also have worse reliability and they just can’t pass smog. Any legitimacy to claims about compactness and power output are because it is a two-stroke. You could take any 2-stroke motorcycle engine from the 1980s and do even better.
The reason you would do better is that the 1982 motorcycle engine does not have the ridiculous waste of weight that all the opposing pistons bring. The modular concept with electric clutch between cylinder pairs is even more a waste of weight. An air conditioning compressor clutch transmits about 5hp, and weights 10 or 20 pounds. This outfit wants to do a 75hp electric clutch? That’s a pretty heavy clutch. And to have more than one, so the last clutch has to do 150 or 225 hp and that would weigh even more.
And just like why hybrids are a waste in the USA, the American drive cycle, the average way we all tend to use our cars, means that we do way too much high-speed highway driving to justify carrying all that extras weight around. Micro hybrids make sense in the USA, use the alternator as a motor under acceleration and to start the car every time it comes to rest. If we lived in countries like Europe or Japan, hybrids might make sense, but this engine in a hybrid still wouldn’t.
The reason is that the valve function in this motor is a constrained by the ports. The ports determine the timing of the aspiration. And that port must be uncovered by the sinusoidal velocity profile of a piston on a crankshaft. If you look at the progress of automotive ICE engines, from about 1952 on, with Ed Cole’s small-block Chevy, everything about blocks and crankshafts were understood pat. A few oiling improvements, but the bottom of the ICE moter has seen hardly any real improvement for 60 years.
All the improvements in ICE engines has been in the top end. There are three areas:
1- The combustion chamber shape. (squish, discovered in 1971 with the 440 wedge motor kicking the butt of the 426 hemi.)
2- The intake track– smaller ports with specific shapes allowing high-velocity charges to take advantage of momentum to fill the cylinder. (Jerry Branch XR-750 heads, circa 1972).
3- Camshafts, i.e. valve actuation profiles. At full RPM, a modern cam literately bounces the lifter and valve off the seat and then catches up with it before it can clack shut and make noise and do damage. These profiles have been perfected to fill the cylinders best over a range of RPM. This opposed-piston motor not only has no way to profile the cylinder filling, worse yet, the timing of the cylinder filling is determined by piston position. After the cam profile itself, pretty well understood by 1980, the biggest advance in ICE engine operation is valve timing, like the brilliant Honda VTEC system. You can’t vary your valve timing with this proposed motor; you are stuck with it.
I have to admit, as a way to get DARPA money, this motor is a pretty good, and I am not implying the people at the company know it won’t work,. I just mean in the sense that statistics and social evolution lets the trickier proposals predominate. See, the failure of this technology will only be apparent at the very end, when they try to smog this thing. That is after they spend millions and years doing all sorts of silly things proving that 2 strokes are pretty cool, other then they fall apart after 20k miles and pollute like crazy as they are doing it.
But they soon will discard the modular concept, since the absurdity of electric clutches and all the weight and reliability problems become apparent. So to the poor SBIR people that have been taken it, what they have to do is establish a firm deliverable: A motor in a car that runs the EPA drive cycle and passes smog. Forget the modules, forget the packaging, forget everything. This thing will never smog and if they hang enough crap on it to get it to pass, after-treatments and urea and whatnot, well, then they can’t make it last for 50,000 miles and weigh less that what already exists.
It just ain’t gonna happen. Look at the article Bruce sent us. There was no tech discussion like I just did because the poor guy that wrote the article did not spend 20 years in Detroit like I did. Instead the article is full of tautologies– self-evident proclamations that justify the greatness of the gizmo. If you could make something lighter, cheaper, more powerful, cleaner, better, smaller, and oh-so-less-carbon, then that would be great. Hence this is great. The only thing missing was the fact that this thing can never accomplish those obviously-good things.
Frank Zappa noted: “Rock journalism is people who can’t write interviewing people who can’t talk for people who can’t read.” Perhaps the same is true for “pop” technology articles. This is why EDN has engineers as editors. We don’t get sucked in by the hype. I feel this is fundamentally a language problem. Say I went up to one of my good friends and started speaking French, or maybe that African dialect where they cluck their tongues, and at the end I said, “so you see you really should give me 40 bucks so I can make you rich.” Well my pal might slap me or have me committed, but they certainty would say: “What the heck are you talking about? Speak English!”
So that is what is so insidious about a complex technological society. People can speak English and still make as much sense my clacking my tongue for an hour. It is certainly a problem with tech people and the gullible public. But it even happens to tech people across disciplines. I routinely see my mechanical engineer buddies getting bamboozled by electrical engineers talking smack. Software people routinely lie to both mechanical and electrical hardware people. Don’t even get me started about medical doctors, or PhD’s for that matter.
It works the other way too, when I try to teach journalism science, like pyramid writing and no passive voice, my tech pals nod their heads and pretend to understand, but they still bury the lede and talk like college professors. It took me 4 years just to get the basic principles and jargon of good journalism down, and I didn’t believe it either when I started.
So I guess if I spoke African, you would scoff and say you don’t understand, but if I speak English, nobody wants to say “You are not making any sense” since they are afraid that they would look stupid since they have spoken English their whole life. This is why good journalists come across as cynics. If the guy that wrote this article assumed the inventor was misinformed, well he might have asked enough questions to figure out this was a boondoggle. At the very least he should have had a source to call up to set him straight. Sorry, no time to check sources anymore, just put up the exaggerated claims and you get even more clicks and a big fat check from the boss.