Elkhardt, IN —Torque Engineering Corp. develops high-performance, gasoline-powered V-12 engines for offshore performance boats. They crank out 900 to 1,150 hp to move these vessels, all measuring over 40 ft, weighing up to 17,000 lbs, at around 145 mph. Built for speed in water—a medium that's 800 times more dense than air—these engines have to withstand great stress without risking safety.
The T1200 is the largest motor currently offered by
Torque Engineering. It is a 1,500 hp naturally aspirated engine with
electronic fuel injection, running on premium 92 octane gasoline.
For around 30 years, these boats used modified big-block Chevrolet engines. But as the boats kept getting bigger and heavier, Torque Engineering decided to develop an engine specifically to accommodate the larger size. After seven years of development, Torque now offers its own 860-inch3 engines, "with thicker walls, crankshaft, and
connecting rods; and made of materials with higher yield and tensile strength
than those used in any engine meant to move a vehicle through air," says Andy
Harman, chief engineer for Torque Engineering.
As part of the new engine design, Harman used SolidWorks from SolidWorks Corp. (Concord, MA) and COSMOS/Works from Structural Research & Analysis Corp. (Los Angeles) to analyze a crankshaft and a rear engine mount. In the case of the crankshaft, Harman wanted to optimize stress within a set of space constraints. He constructed a partial model—a one-throw version of Torque's six-throw crankshaft—constrained it, and applied a basic rod-bearing load. Over several scenarios, including a variety of fillet sizes, web thicknesses, and journal sizes, he worked to minimize the stresses created by the load. The more robust optimal design had its factor of safety raised from 8 to approximately 13. A factor of safety of 1.0 (the material yield strength) is the minimum acceptable.
Harman's second study looked at the rear engine mount—the supporting frame securing the engine to the boat. He analyzed the existing engine mount by applying half the engine weight and an accepted acceleration load vertically to the mount. Once he knew which areas showed the greatest stress, Harman tried different shoulder fillets and gussets to improve the stress resistance. Ultimately, he lightened the weight of the mount from 18.5 to 16 lbs, and increased its factor of safety from 1.3 to 4.
"We've got stronger pieces now that don't cost any more to manufacture," says Harman. He says that he also saves a great deal of time by using SolidWorks and COSMOS/Works. Coming up with a 2D wireframe design and analyzing it "was always a one- or two-month process. In contrast, I spent about a week on the rear engine mount and two weeks on the crankshaft," he says.
For more information about CAD from SolidWorks Corp.: Enter 534
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