Imagine engines weighing under half of what they do normally. Made of plastic. Now believe it when I say we could to this 35 YEARS AGO. WHY aren’t Polimotor’s plastic engines in play?!

“Torlon parts are perfectly suited to the engine, because they are strong and tough at temperatures up to 500 degrees F. While some other plastics may take this temperature, Torlon poly(amide-imide) offered [eng Matti Holtzberg, founder] a material which can be fabricated to precise detail via injection molding. This economical process lowers unit cost, a critical factor for commercialization of the technology, given the relatively high price of the plastic when compared to traditional materials.”

- So we know that mass production is feasible, the high startup costs (tooling etc) could easily be dealt with by major auto manufacturers, and we know automakers are not averse to even more extreme efforts.

Terry Lappin, Manager of the Engineering Resins Department at Amoco... adds, “plastic engine parts can stand the stress of racing and before long may appear in passenger cars too. We are capable of producing commercial quantities of Torlon engine parts now. It’s up to the car companies.”

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  • 1979 - Polimotor creates a replica of Ford’s 2.3l from the Pinto in, 69kg/153lb vs 415lb stock!!
  • Race proven - Partners with Lola to race Cosworth engine at IMSA - 1984 endurance: 5hrs @ 8-9krpm, 318hp@11krpm, 14k max, 153-168lb (conflict: sources)
  • Economy - now more than ever, mpg and CO2 emissions are scrutinised. eg:(100kg) 220lb off = save ~10g CO2/km and ~6-7% fuel consumption (saving €100/ÂŁ83/$135 per year)

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Note: The price of these individual units put it firmly for “healthy” race teams - cost of Polimotor 234 [2.3l i4] (175lb, 175hp@5.8krpm) was $15-17k then!! But like I said before, manufacturers can offset this with mass production.

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Technical info (components):

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  • Piston heads are metal (to trasnfer heat away), and the skirt is made of Torlon polymer. “The part is 35% lighter than an all-metal piston. Decreasing the weight of powertrain components reduces secondary shaking forces, which are of major concern in today’s four cylinder engines.”
  • “The con-rods in the Polimotor Lola are made of Torlon-C, a developmental advanced thermoplastic composite from Amoco Chemicals. It represents a 49% weight reduction versus metal.”
  • “Torlon parts are not only tough, they can absorb impact energy better than metal, which is one reason why the material is suited for wrist pins.”
  • “More than 75% of the weight of an intake valve is cut by substituting Torlon stems for steel...
  • “Inverted bucket-type tappets made of Torlon polymer contribute to the lower weight of valve train components, which reduces inertia and decreses the spring load needed to prevent valve float.”
  • Torlon timing gears... used “as-molded”... no hobbing

Torlon polymers are characterized by outstanding modulus, impact strength, shear strength, fatigue strength, and creep resistance. However “Torlon (poly amide-imide) by itself has quite meager properties when compared with other materials. For example, its tensile yield strength is ~ 190 MPa, its tensile elastic modulus is ~ 5 GPa, its mass density is 1.4 * 10^3 kg m^-3, and its thermal expansion coefficient is 30 * 10^-6 deg C^-1. While these are quite good for a polymeric material, and could be improved with a reinforcement (e.g. glass fibers, mica particles, etc.), they certainly do not exceed those of other materials, for example a magnesium alloy.” But then, if purely from a mass-manufacturing of economy cars pov, if you can match or almost-match current material properties with these massive weight savings...?!?! It’s infuriating!! WHERE IS THE INVESTMENT FOR THIS FROM FORD? LOTUS??!

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THEY CAN’T ADD BETTER LIGHTNESS THAN THIS.

EDIT:

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Disclaimer:

This article is a lot of copypaste but I have cross-referenced and favoured reliable sources when creating this article. I do not have copyright for images here but this blog is not for personal gain, it is to raise awareness in my fellow Opponauts and Jalops and maybe get to the bottom of all this indifference to something so promising!

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RELATED

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Resources:

http://forums.autosport.com/topic/56971-po… Much thanks to Cory Padfield’s and EngineGuy’s posts from the forums - invaluable for this blog!

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http://www.arpro.com/news/article.p… (CO2, chassis)

http://www.ecodrive.org/en/what_is_eco… (mpg)

http://www.nytimes.com/2009/10/25/aut…

http://www.dailytech.com/Plastics+Engin…

http://www.dirtbikeworld.net/forum/showthre… (good compilation of pics)

http://www.lolaheritage.co.uk/scrapbook/004/…