WHEN the Boeing 787 airliner goes into commercial service next year, travelers will be transported on wings and fuselages made of advanced composite plastics. This raises a logical question: if modern plastics are sturdy enough for 600 mile-per-hour airplanes, why are car engines still made by pouring molten metal into molds, a 6,000-year-old process? That inequity is especially grating to Matti Holtzberg, a New Jersey engineer who has spent 30 years trying to send iron and aluminum engines the way of the woolly mammoth. The plastic powerplants he designed and built in the 1980s proved tough enough to race in professional motorsports.
But Mr. Holtzberg failed to persuade carmakers that the benefits — major weight and cost savings — were worth the risk. So, like the long-lasting battery and the driveway-ready hydrogen fuel cell, plastic engines remain just beyond fruition. What keeps Mr. Holtzberg going is the occasional ally he converts to his way of thinking. Recently he formed a strategic partnership with the Huntsman Corporation of Houston, a global chemical company with 12,000 employees and annual revenues of $10 billion. Huntsman’s proven record as an auto industry supplier may bring the clout needed to move plastic engines out of the laboratory and onto the proving grounds where auto engineers are searching for ways to meet the next round of fuel economy targets.
Mr. Holtzberg is not the first pioneer to be frustrated in an attempt to move plastics to the mainstream. Henry Ford was an early champion of plastics, commissioning projects to explore alternative materials for car bodies in an era when steel was in short supply because of the military buildup for World War II. And he took the lead in promoting the concept: in 1941, he whacked his personal car with an ax to demonstrate the toughness of an experimental plastic trunk lid. For years Ford cars had been equipped with plastic horn buttons, shift knobs, door handles and timing gears molded from soybean meal. Ford was drawn to plastic for its cost- and weight savings as well as its corrosion resistance.
Six years after Henry Ford died, his dream was finally realized. The first of more than 1.5 million Chevrolet Corvettes with fiberglass body panels began rolling off General Motors assembly lines in 1953. Since then, cars have benefited from a steadily rising plastic content. The typical North American-made vehicle now contains over 300 pounds of the stuff, according to the Energy Department, making it the second largest material type behind steel. But major powertrain structural components — engine blocks and cylinder heads, transmission cases and axle housings — continue to be iron or aluminum castings because of the heat and stress they must endure.
Mr. Holtzberg’s efforts to change that can be traced at least to 1969. Reading a magazine article at the public library in Hackensack, N.J., he learned of a new plastic said to be tough enough to withstand the harsh conditions inside engines. He obtained a sample, made a piston with it and installed it in the engine of a friend’s Austin Mini. The plastic piston lasted 20 minutes.
Mr. Holtzberg pressed on. During the 1970s, he made and sold plastic pistons — now with aluminum crowns to withstand combustion temperatures — and plastic connecting rods for racing engines. In ’79, he founded Polimotor (the name is shorthand for polymer motor) to develop plastic-intensive engines. The first Polimotor, a clone of the Ford Pinto 2.3-liter 4-cylinder, used plastic for the block, piston skirts, connecting rods, oil pan and most of the cylinder head. Bore surfaces, piston crowns and combustion-chamber liners were iron or aluminum. The crankshaft and camshaft were standard metal components.
Shortly after Mr. Holtzberg’s first engine successfully ran, an article in Automotive Industries, a trade magazine, inquired, “What...a Plastic Engine?” Two years later, Popular Science featured a Polimotor on its cover. By then, Mr. Holtzberg had progressed to a second-generation 300-horsepower design weighing 152 pounds; a stock Pinto engine made 88 horsepower and weighed 415 pounds. To prove that his plastic powerplant was durable, Mr. Holtzberg campaigned a Lola racecar in the International Motor Sports Association’s Camel Lights series. Amoco Chemical provided financial backing to promote its Torlon plastic resin. The only mishap during half-a-dozen 1984 and 1985 races was the failure of a connecting rod, a part purchased from an outside supplier. In spite of his successes, Mr. Holtzberg roused little attention. “Ford was technically interested,” he recalled. “The Popular Science article gave them plenty of free publicity, but they actually contributed nothing to the Polimotor project.”
Mr. Holtzberg persevered with plastics better suited to mass production. In 1986, he shifted his focus to phenolic resin, the same material Henry Ford used to bond the soybean fibers in his experimental car body. Mr. Holtzberg still holds patents covering polymer formulations and techniques for casting resin reinforced with fiberglass in the type of molds in wide use. He views his composite casting technology as the next logical step in the evolution of the automobile, from wood, iron and steel to aluminum, magnesium and advanced plastics. Huntsman will supply the epoxy resin and aid in engineering and marketing efforts. Mr. Holtzberg said that his materials could trim an aluminum engine’s weight by 30 percent to 35 percent, but that’s not its sole appeal.
“After 25 years of effort, major foundries are finally inquiring about my process,” he said. “Witnessing the demise of steel making and iron casting in America, and experiencing the loss of a significant share of their business to Asia and India, they’re interested in advanced casting processes that can trim both material and machining costs.” Seventeen licensees are using Mr. Holtzberg’s approach to manufacture rapid-prototyping components. Ed Graham, engineering manager at ProtoCam in Northampton, Pa., said that his company had used Mr. Holtzberg’s technology to make engine parts for three years. “The thermoset phenolic material is strong and has excellent heat resistance,” he said. “The process is quick, and the parts go straight into experimental engines and transmissions.”
James Huntsman, vice president of the advanced materials division at Huntsman Corporation, hopes the success achieved in prototype composite-plastic parts will spur interest in low-volume production applications. “We realize that supplanting proven processes is a long and difficult challenge,” he said. “We’re convinced that the time is right for a composite engine.” Of course, there are skeptics.
“While half of the aluminum car wheels now come from China, the foundries supplying major aluminum power train castings are captive,” said Richard A. Schultz, a consultant at Ducker Worldwide, using the industry term for operations owned by the automakers. “Energy consumption is not an issue, their aluminum scrap is readily recycled, and the cycle time with plastic would surely be longer.” Jay Baron, president and chief executive of the Center for Automotive Research in Ann Arbor, Mich., pointed out that the auto industry is staunchly risk-averse. “They’re not about to manufacture thousands of vehicles with engines that could fail in service,” he said. “Since plastic engine castings are outside any car company’s mainstream business, all the cost, processing and durability issues would have to be resolved in the supply base.”
Before internal combustion is finally superseded by electric propulsion, there’s time left for a few more technological breakthroughs. Mr. Holtzberg and his Huntsman partners are betting that composite-plastic engines make the cut.
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