Dynamic Balancers
| ITEM | DESCRIPTION |
|---|---|
| 1 | Bearing outer race (4 off) |
| 2 | Dynamic balancer - Left |
| 3 | Gear - Left dynamic balancer |
| 4 | Bolt (2 off) |
| 5 | Bearing |
| 6 | Bearing |
| 7 | Idler gear |
| 8 | Gear - Right dynamic balancer |
| 9 | Dynamic balancer - Right |
The engine balance system consists of two eccentric weighted dynamic balancers which oppose vibrations created by the engine's reciprocating components. The dynamic balancers are mounted on outer races pressed into machined bores inside the cylinder block. The two dynamic balancers rotate in opposite directions, driven at twice the speed of the crankshaft by a dynamic balancer gear pressed onto the crankshaft. The equally sized eccentric weights are phased so that the inertia reaction to their counter-rotation cancels out vibration caused by the engine.
The left dynamic balancer is driven off an 86 teeth ring gear located on the crankshaft that rotates a 43 teeth driven gear on the driven dynamic balancer. The right dynamic balancer is driven off the same ring gear through a 45 teeth idler gear. The idler gear rotates the 43 teeth driven gear on the driven dynamic balancer.
The idler gear is mounted on to the cylinder block using a steel idler bush which is pressed into the cylinder block. Driven gears on one of the dynamic balancers and the idler gear are anti-backlash scissor gears in order to minimize noise. All the gears are helical to make sure the smooth operation. The dynamic balancers are located on needle roller bearings that run on outer races installed in the cylinder block machined bores. The bearings are lubricated by oil mist during engine operation.
It is important to make sure that each dynamic balancer is timed correctly in respect to the crankshaft, using specialized alignment tool(s).