New toyota technology2

The block is aluminum (versus cast iron for the previous engine) and it has a structural aluminum crankcase that helps eliminate vibrations. Also aiding engine smoothness is the block architecture. It's a compact design with the water pump chamber cast flush with the front, and the side shaped for bolting on the air conditioning compressor without brackets.

Toyota's "total flow" approach to improved engine cooling means all of the coolant flows in a continuous path around the block, then up to the cylinder head. Toyota (and General Motors) began using this technique several years ago, and now it's being phased into this and other new Toyota engines.

The pistons employ Toyota's new "taper squish" shape. The squish part of that name refers to the rising piston's tendency to swirl the air-fuel mixture for more complete combustion. Another neat engineering feature is the offset crankshaft, which - unlike conventional engines - is located 10mm (0.4 in.) laterally (toward the exhaust side of the engine) from dead center under the cylinder bores (illustration below).

The benefit? This allows each connecting rod attached to the crankshaft to still be at an angle (relative to the cylinder bore vertical centerline) when the piston reaches the top of its stroke. Then, as the crankshaft continues to turn, the rod finally lines up with the cylinder centerline just when the piston's power stroke is developing its peak pressure. As a result, the straight downward force from the piston to the connecting rod to the crankshaft is greater, and the side forces - versus a conventional design - are lower. This reduction in side forces means less friction. Other engines sometimes have the piston pin placed off-center to get a similar effect, but this offset crankshaft design is superior.