You are absolutely correct Contrarian; I've already seen a few plastic part failures, specially in intake manifolds that suffered some degree of deformation and caused some terrible vacuum leaks, that no known sealer or gasket was able to solve. I'm afraid that car reliability and durability in present day design is somewhat wrong: (at least) some cars can perform admirably for maybe 5 to 6 years, even without a single sparkplug change, but then start to fail miserably, as if those would have been "designed-to-fail"... Still, there are many other designs that are known as "nightmares or true collections of problems". Just read many "Made by Monkeys" issues and you will understand me. But the main thing is: WHY an automobile has to be destroyed and completely replaced every 5 years or sooner, just to keep the line producing more and more less than problem-free vehicles? Is that some weird kind of badly understood "sustainability"? In my case, I have already been busy replacing at least some "extraordinarily advanced" plastic parts that failed miserably:
1.- The fiber reinforced Nylon stabilizer bar links that failed and started to crack in my Chrysler. The Dealer that provided me with the replacement (fortunately made from metal) part happened to have a much more expensive Corvette, that suffered exactly the same problem, A potentially dangerous accident waiting to happen. He too, replaced the failed links with aftermarket, specialty duraluminum links. Metal=1, plastic=0.
2.- A friend's wife car suffered a catastrophic engine overhating episode... the culprit: a very advanced coolant pump impeller in her VW that decided it was time to rest, and took the engine with it. Not only it was expensive, but she was stranded in a remote place for hours, a terrifying experience she won't forget easily. Other known plastic impeller failures encompass several brands of cars, as the pump manufacturer makes efforts to lower the overall cost of the pumps. (metal impellers require balancing, but plastic impellers cause lesser vibration even when unbalanced due to their lower weight).
3.- The very frequent failure of VW glove box in the dash, that is entirely made from plastic. The internal latch mechanism relies on some insufficiently sized plastic pins that hold two "tee" shaped parts that pull the plastic latches... those break and leave the owner having to buy an entire glovebox assembly... that will break again soon. Thanks to adventurous and extremely helpful intelligent people that published the improvised repair of this constant problem on YouTube, I was able to know how to BREAK open the halves of the door lid, and how to repair it. (the halves are welded together with ultrasound, to save a few pennies on manufacture, and to help the Stealership in robbing its customers by selling them a quite expensive entire replacement glovebox).
Really enjoyed your phrase: "for the most part this penny shaving is false economy"... couldn't say it better myself! Amclaussen.
In profesional racing, plastics are already being used, as cars have to last a race and no more. But for daily drivers, plastics still have some limitations and present some problems. Weight reduction is very desirable, as most automobiles now are way overweight, but there is a point at which further reduction will reduce safety indeed.
But I'm sorry for future owners of overdone plastic engine component substitution: Made by Monkeys will be full of complaint cases! There are some parts where plastics are at an advantage, but extraordinary efforts by plastic making companies will cause a lot of headaches for owners where plastic engine component (ab)use will mean problems, more maintenance or shorter life span. Few lab tests and endurance checks will uncover all defects, shortcommings and setbacks. Good luck.
Thanks, AnandY. To be clear, the article states that it's not a plastic engine: it's a plastic engine manifold. What's new is the crossover coolant piece, which used to be metal, and is now also plastic.
The new plastic engine seems to have many new and attractive features that make it better than the old metallic engines. After reading this piece, am sure that Ford drivers (me included) will be wondering if they plan to develop similar engines for the other models that are still in production. It would be very nice if they could and even better if they were to sell such engines separately. Am sure I would opt for the plastic engine if I ever need a replacement.
Interesting piece Ann. It's good to know that Ford have discovered a new and cost effective way to make engines for the new car models but my question is are these savings significant enough to be transferred to and enjoyed by their customers as well, especially those who buy the new car models?
Thanks bobjengr for the input on the use of Moldflow and similar software optimization techniques, and their value. I was blown away by the abilities of some of this software, as I wrote about after the Altair Technology Conference: http://www.designnews.com/author.asp?section_id=1386&doc_id=268622 http://www.designnews.com/author.asp?section_id=1392&doc_id=269073
mtripoli3, I know how much Mercedes has declined. I went through about the same cycle you did from wanting to purchase to being able to afford to purchase. The increase in plastic parts has certainly changed the feel of cars at the high end.
Those are good points you bring up regarding the repairability--or lack thereof--of plastic vs metal parts, mtripoli3. Thanks for that. I have a plastic rear bumper, too, on my 1996 Nissan Sentra. It's not as cheaply made as your Mercedes', I'm glad to say. But when the paint started peeling off it several years ago it made me unhappy when I found out the greater difficulty and higher cost of repair.
Besides recycling, what is the environmental cost of these materials? Freon, Teflon, and so many other advanced DuPont materials have had lasting environmental impacts.
Another is longevity, engine parts made of metal except for a few special cases last essentially forever.
I've seen a lot of these plastic components used in cars already fail dismaly after a relatively short time in service.
Further to someone elses question about use in racing, that has already happened. I recall reading in "Popular Science" about 10 years ago about Ford adding an additional 100HP to an engine by making the pistons out of plastics except for the crown. It's a while ago that I read it, but there was a lot of other non-metal parts which I won't list for fear of remembering incorrectly.
In racing of course lifespan doesn't matter as long as it's one race. The environment also takes a back seat.
Most of the new 3D printers and 3D printing technologies in this crop are breaking some boundaries, whether it's build volume-per-dollar ratios, multimaterials printing techniques, or new materials types.
Independent science safety company Underwriters Laboratories is providing new guidance for manufacturers about how to follow the latest IEC standards for implementing safety features in programmable logic controllers.
Automakers are adding greater digital capabilities to their design and engineering activities to promote collaboration among staff and suppliers, input consumer feedback, shorten product development cycles, and meet evolving end-use needs.
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