At the heart of the Vehicross is Isuzu's updated 3.5 liter 6VEI engine. This features a variable intake system which employs an air intake valve and intake port that can be regulated to provide higher volume efficiency. When the engine is running at 3,600 rpm or less, a solenoid closes the variable air intake valve. At this point, the effective air intake port length extends from the lower intake opening to the intake valve. This long port increases volume efficiency, providing high torque at low and intermediate speeds.When the engine is running at 3,600 rpm or more the solenoid turns off, opening the variable air intake valve. At this point, the effective air intake port length extends from the intake opening of the variable intake valve to the intake valve. This short port increases volume efficiency, providing high torque at high speeds.    The cylinder heads are made of die-cast aluminum alloy for lightness. A DOHC 4-Valve cross-flow configuration is used; the combustion chambers are pent-roof type with squish areas. The valve angle is 19º in order to make the combustion chambers more compact. Additionally, the squish areas allow reliable combustion at low rpms.Combustion efficiency is further increased through reduced friction in the main drive system, valve system, and through more compact combustion chambers. This results in better fuel economy and performance.    The DOHC 4-Valve configuration features narrow intake and exhaust valve angles by using a direct attack valvetrain. This also results in lower friction and weight, hence reduced noise and improved engine response and efficiency. Valve lift and timing have been optimized to improve torque at intermediate speeds and boost maximum output. Fine finishing of the cam profile sections also reduces frictional resistance.The combination of a two-stage reduction gear drive and a backlash-free gear configuration provides high-precision valve timing and reduced noise.    A traditional oil pan has been replaced by a two-stage structure consisting of a highly rigid die-cast aluminum crankcase and a steel oil pan to prevent bending of the skirt portion of the cylinder block. This results in greater combined rigidity of the power plant, including the transmission housing, and helps reduce vibration and noise. An engine oil cooling fin, mounted on the bottom surface of the crankcase, reduces oil temperature and eliminates the need for an oil cooler.    Common chamber gaskets containing heat insulation (phenol plastic) are also used to reduce the engine's air intake temperature and increase output performance.Vibration damping rubber is used in locations where the cylinder head cover and timing belt cover are fixed in place, thereby creating a full-floating configuration. This further helps dampen engine vibrations.    The need for maintenance is also reduced through the use of platinum spark plugs and a serpentine auxiliary drive belt. The spark plugs are fired by a Formula 1 racing inspired, direct coil over plug ignition system for a hotter, more reliable spark, and require no maintenance for 100,000 miles. A serpentine layout, in which all auxiliary components are driven by a single belt, is used. An auto-tensioner ensures that the belt tension never needs to be adjusted manually and that stable tension is always maintained. This helps to reduce the need for periodic maintenance and extends engine service life. The belt is made of polyester and has six teeth per "V" unit of length.    In order to further boost output performance by delivering cool air into the engine, the outside air intake duct is located inside the front fender on the left side, rather than inside the engine bay.

---