Piston pins holding the pistons in place are locked by snap rings. This is sometimes referred to as a 'non-interference' engine. An indentation is incorporated into the piston head to prevent the pistons from hitting the valves, should the timing belt break (this is not true of the 3S-GE BEAMS motor). The pistons are made from an aluminium alloy, designed to withstand high temperatures. To adjust the valve clearance, adjust the shims above the valve lifters. The 'Outer Shim Type System' allows for the replacement of the shims without the need to remove the camshaft. The cam journals are lubricated by an oiler port located in the middle of the camshaft. The cam journal is supported on five points between the valve lifters of each cylinder and on the front of the cylinder head. The intake manifold has four independent ports and benefits from inertia build up to improve engine torque at low and medium speeds.Ī single timing belt drives the intake and exhaust camshaft. Oil holes are located in the middle of the crankshaft to provide oil to the connecting rods, bearing, pistons and other moving components. The crankshaft, located within the crankcase, rotates on five aluminium alloy bearings and is balanced by eight weights. The ignition order of the cylinders is in the 1-3-4-2 order. The spark plug is located in the center of the combustion chamber. The pent-roof combustion chambers are complemented by a cross-flow intake and exhaust layout. The cylinder heads are made of aluminium alloy. The cylinders are numbered 1-2-3-4 with cylinder number 1 beside the timing belt.

The Toyota 3S-GE is an in-line 4 cylinder engine manufactured by Toyota as part of the S engine family and tuned by Yamaha Motor Company.

Toyota altezza engine specs