I can't think of any way to justify the time and effort put into this engine, I'm kind of sad that I wasted the time reading this article, as are the people at the show that bothered to stop and look at it. Novelty at best. Complete waste of time at worst.
The purpose is for model vehicles. I have seen many scale model jets powered by real jets engines, scaled down. People who have the money to do this type of thing do it because they find it interesting and a challenge. I have watched these jets flown remotely at real speeds of 200MPH. Now that is a feat. Is it practical or important? Well, frankly no. Is it interesting and a challenge. Well, yes. Just discovering the issue with the oil is interesting. Who knows, there might even be a practical use for this knowledge in the future.
You are absolutely right, and the solution with cross-hatching of the walls of the chambers did not go unnoticed, and may serve some purpose in the future. My point was simply that the time and money could have been spent on something more productive and gained a better insight into something. This is old technology and certainly not something they were modeling to find a better way to do something. They were just having fun, and that's ok, because many advances in technology happen when trying to accomplish a different goal.
I would be curious to know if some kind of synthetic oil would have worked better in this situation, maybe we should get out of this, that oil may not be the best solution for lubricating, or that explosions and pistons are not the best way to propel things at this scale.
It's a cute project, and I understand perfectly how he must have felt when it worked. I wondered how a teflon engine coating such as Slick 50 would work here? I put that into the 1.8 liter motor in my Pontiac Firebird and got 15% better mileage and drove that car well into the 200k range, 230 IIRC,
I totally agree, TJ, I was a little harsh in my first post, and I did admit subsequently that there is something interesting here, but I like to see new and exiting useful technological advances here. The problem they overcame with the cross-haching is, I suppose a Design News kind of item.
@akwaman: Cross-hatching is actually the typical surface texture for cylinder liners. The plateau-honing process described here is common. (Actually, it's more common to use a three-stage process rather than a two-stage process; the third stage cleans up the excess material left in the "valleys" after shaving off the "peaks"). You can find out way more than you ever wanted to know about cylinder liner surface texture here.
What's mainly interesting here is the small size of the engine. As a materials guy, I'd also be interested to know what the liner material is. I'm guessing it's probably gray iron, but not all iron is created equal. We've found that the cross-hatch pattern you achieve depends not only on the honing stone, but also on the microstructure of the iron.
As the document I have linked to shows, quantifying what a "good" hone pattern is is a very difficult task.
Yes, I too am astonished that the cross-hatching cylinders here is so celebrated. This was discovered and implemented by engine makers decades ago. That is the reason engine reboring and honing has pretty much disappeared. Now when they fix a car, they leave the basic block alone.
As for oil not scaling...seems an invented problem to me. They make lots of oils for very fine machinery. The cross-hatching was not necessary simply becasue they couldn't find oil for it, that's just the proper way to make an engine cylinder and bore.
Sometimes going one way with research or development ends up nowhere near the expected destination, and that can be a good thing. Not always, to be sure, but sometimes it can change the world. Years ago there were a couple of books that explored the phenonmenon: James Burke's Connections and Joel Barkers book on future (I forged the exact name). Also, there can be a time lag in the time it takes to get from the original thought to a useful application, not to mention an optimized solution of that application: to wit see link: http://en.wikipedia.org/wiki/Lohner-Porsche . 1901 idea coming around again.
Personally, I think it's great. I'd bet some application will be found, though it may be at a less than 8 cylinder size, and maybe not used in a "vehicle" as we know it.
I agree, we never know at first where our ideas will lead. I think it is a good strategy to "waste" a certain amount of time just exploring mentally and building a few prototypes. It's also a lot of fun and you never know where the ideas and techniques you find will be useful.
As for applications, I would think that improving battery technology especially energy density would make electric motors a better choice since they are so much simpler mechanically. The complexity of a single cylinder/piston subassembly in any internal combustion engine is greater than the entire electric motor of similar size.
The power curve is much flatter with loads of torque immediately. The Tesla cars have only one gear, and reach 60 in 3.9, 5.9 or 6.5 seconds depending on how much money you put into the battery size.
This reminds me of the change from steam to diesel in locomotives. Newer tech is simpler and costs less, but the old school stuff is more fun to work with, and easier to understand because you can see different parts pushing and pulling.
>> he hopes to scale up his runs to between 150 and 180 of the units, which cost between $5,600 and $7,500 each.
This gives a hint into the purpose of the effort. A lot of us think it's worthwhile simply because it's cool, but there appear to be people that think it's cool enough to trade their money to own one. This makes the effort both a cool and practical use of time/resources.
I bought my 91 Honda CRX for 5 grand a decade ago. Spent a couple of grand on over the years, great car. Something like this looks like throwing good time after bad, unless you happen to be Jay Leno. Now if he owns one that is a different story...
Not to pick on the original "purpose" post [I most definitely am not]. I often think about those who are hypercritical of auto racing... "for what purpose?" they ask again and again... to get nowhere, round-n-round, in a big polluting hurry. Well I am one of a growing number of people that COMPLETELY understands why, what, and how this all has a purpose. I like the auto racing example because it exemplifies itself in some of our cars every day. When relatively strapped for cash I bought a 1996 Dodge Intrepid for my family hauler and grocery getter. It had 4-wheel independent suspension, loads of safety features, disc brakes on all four corners, a very low cg, Z-rated Low-Pro tires, cast aluminum wheels, short ratio steeting, the list goes on... NONE of those features came to the 4 door sedan without the tried and true venue of auto racing. Comparing that machine to the leaf spring carbeurated P.O.S. that was my dad's family hauler and grocery getter circa 1977.... YUP, there's a purpose. Oil chemistry and film retention technology are both HUGE factors in today's world as we up the power density on engines of any/all cylinder configs. While I agree that this project has limited applicaiton, the value of the lessons learned from it are yet to be calculated. Great posts, everyone!
The best place to see model engineering at its best is the annual North American Model Engineering expo held each year in the Michigan or Ohio area. They display everything from half scale farm tractors to working motors the size of a No. 2 pencil eraser. Some amazingly talented people (most seem to be retired tool and die men) create and display the most amazing working models purely for the fun and challenge.
WHY is it any of your concern how this fellow spends his time & money? IF your neighbor enjoys fishing, and you see no real value in it, do you tell him he's ridiculous for pursuing his hobby/enjoyment?
I think your position regarding this engine development is at the least, ludicrous, and at the worst, arrogant to the nth degree!
IF nothing ever comes of the the knowledge gained by this exercise, so be it. But, those involved thought through a difficult problem to an acceptable solution. I say, BRAVO! to them. Hopefully, some young engineers reading this article will become fascinated to the point of nurturing a "seed" in their own minds!
This is TOTALLY AWESOME! Engineering at it's best. Find a difficult challenge and then find an innovative solution. The idea of putting valleys on the cylinder walls is genious. I wouldn't have thought that the molecular size of oil would matter or that oil would be the limiting factor.
As for the detractors, time to start living again and seeing the beauty in the world around us and the fun and excitement of exploration. I have no doubt that this innovative design will be used in many more 'lubrication intensive' designs.
Ditto that Xjandin. I thank the Thor daily that RF scales down nicely. Forget what the naysayers think. Another 'for what purpose' is I had a Vette that would do 120mph and live in an area where the max speed limit is 55mph. For what purpose? No purpose, I just loved a car that would slam me into the seat from a dead stop. Today I drive a 'mild' Mustang GT convertible. Old age is setting in.
But his engine is indeed awesome. An engineering WOW.
@Xjandin: I think nearly everyone agrees that a working V8 engine on this scale is an exciting development. But as for putting valleys on the cylinder liners, that's nothing new. Plateau honing has been around pretty much forever. It's not quite clear from the article what's new about the honing (other than the scale).
I have to agree with the general tone of most responses that this is an amazing engineering achievement. A supercharged V-8 is already loaded with engineering innovation. To shrink that down to 1/4 size, I'm sure Mr. Conley had to solve more problems than just this oil retention issue. With national mandates to improve passenger car mpg, this development may not seem quite so out of the mainstream a few years from now.
It is quite an accomplishment and praiseworthy indeed. However, developing 13hp is a far cry more down-sized than the 1/4 size scale of the engine. One would expect a great deal more than 130hp from a full-sized super-charged V8. It appears that the power-to weight ratio doesn't scale very well.
Kudos for overcoming the difficulties and achieving this amazing engine.
I, too, am impressed. The challenges must have been incredible! It goes to show that things aren't always to simple as they might first appear. Just like when they were scaling down IC manufacturing, the smaller lines created all sorts of optical and delivery problems.
Too bad I didn't get to see it. I am always impressed by someone who does a really good job! Kudos to you and your team!
mcj804: The engine puts out 9.5 bhp, not 13. The 13 lbs cited in the story is the amount of boost from the supercharger. The article doesn't give the weight of the engine, so we can't compute the engine's power to weight ratio. The correct way to evaluate the power output is to say that its specific output is 1.56 bhp/cu.in. This is pretty good. Two of the highest output American V8 engines are those in the 2013 Ford Shelby GT500 (1.86 bhp/cu.in.) and the 2013 Corvetter ZR1 (1.69 bhp/cu.in.). The V6 in the 2012 Honda Accord EX-L is rated at 1.28 bhp/cu.in.
As manufacturers add new technologies to their products, designing for compliance becomes more difficult. Prepare for the certification testing process. Otherwise, you increase the risk of discovering a safety issue after a product leaves the assembly line. That will cause significant time-to-market delays, be much costlier to fix, and damage your brand in the eyes of customers.
Stratasys will be exhibiting two groundbreaking large-scale additive manufacturing technologies, as well as other new products, next month at the International Manufacturing Technology Show (IMTS) in Chicago.
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