Are composite engines the Engine of the Future?
Carbon-fiber composites have infiltrated practically every nook and cranny of today’s supercar. We’ve got carbon monocoque structural cores, carbon-ceramic brake rotors, and carbon-fiber-reinforced body panels. Taking this approach to the radical extreme, Formula 1 constructors have long used molded carbon-fiber suspension, wing, and transmission-housing components. Contemporary F1 steering wheels are even made of this light, stiff material to save a few ounces.
Ironically, the single heaviest part of practically every car—the engine block—is one of the last items awaiting conversion from metal to molded carbon fiber. Enter Florida engineer Matti Holtzberg. For the past four decades, he’s worked to create an ultralight plastic engine with sufficient stamina to replace engine blocks made from cast iron or aluminum. With strategic use of inserts to handle the heat and concentrated loads, he has engineered a composite engine block that may be ready to send cast metal the way of the buggy whip.
After years experimenting with various resins reinforced with glass fibers, Holtzberg recently expanded his focus to include more expensive carbon-fiber materials. Realizing that the hard-core racing community is always eager to gain a competitive weight-saving edge, he knew there was a market for a composite cylinder block capable of trimming a few pounds. Indulging his best entrepreneurial instincts, he purchased tooling and configured his West Palm Beach lab to cast the first dozen carbon-fiber-reinforced engine blocks patterned after Ford’s 2.0-liter Duratec engine.
According to Holtzberg, his mold is a six-piece aluminum jigsaw puzzle consisting of a base plate, four side panels, and a top cover. A removable core, which forms the water jacket, oil drains, and main oil galley, fits inside. During assembly, the mold also is loaded with various aluminum parts: 71 threaded inserts and five main bearing saddles. After casting, four Siamesed cylinders are placed in the water jacket.
After prepping the mold, epoxy resin and six-mm-long carbon fibers are stirred together in an industrial mixer. The resulting batter, which has the consistency of oatmeal, is warmed slightly and then poured into the mold. It’s left to cure for two hours, although Holtzberg adds that minor procedural changes would allow molding a block in only five minutes.
One of the attributes associated with this accurate molding process is that the composite surfaces require no finishing operations and minimal machining is necessary. After casting, the main bearing saddles are line bored and the cylinders are cut to accept liners. Holtzberg plans on switching to a molybdenum plasma spray coating in place of aluminum cylinder liners to trim additional pounds. That will boost the weight savings over an aluminum block from 18.2 pounds to more than twenty pounds.
Holtzberg will add several carbon-fiber bolt-on components, such as the oil pan, cam cover, intake manifold, and fuel rail to create a kit he intends to offer racers. After purchasing the kit, each customer can commission their favorite engine builder to assemble the package according to specific racing or rallying needs.
Holtzberg has not yet established a price for his carbon-fiber engine, but it’s unlikely many Ford Focus owners will be interested in spending what could be $2500 (or more) per pound of weight saved. Car And Driver