Dynamic Balancers
| ITEM | DESCRIPTION |
|---|---|
| 1 | Bearing outer race (quantity 4) |
| 2 | Dynamic balancer - Left |
| 3 | Gear - Left dynamic balancer |
| 4 | Bolt (quantity 2) |
| 5 | Bearing |
| 6 | Bearing |
| 7 | Idler gear |
| 8 | Gear - Right dynamic balancer |
| 9 | Dynamic balancer - Right |
The engine balance system consists of 2 eccentric weighted dynamic balancer shafts which oppose vibrations created by the reciprocating components of the engine. The dynamic balancers are mounted on outer races, pressed into machined bores inside the cylinder block. The 2 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 has a 43 teeth drive gear that is driven by the 86 teeth ring gear on the crankshaft. The right dynamic balancer is also driven by the 86 teeth ring gear by a 45 teeth idler gear. The idler gear makes sure that the 2 dynamic balancers rotate in opposite directions.
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 1 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 that they operate smoothly. 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).