ABOUT BALANCING

I am sure you have gone through and read many websites that have a 20-page scientific novel about balancing. Even Wikipedia has a great explanation about it.  Here is a version without any math or scientific technical terms.  

Engine vibrations arise from imbalances in moving parts, categorized into reciprocating and rotating components.

Reciprocating Components:

• Pistons and Connecting Rods: Their up-and-down motion can cause vertical vibrations if their mass or movement isn't uniform.

Rotating Components:

• Crankshaft and Camshafts: Uneven mass distribution during rotation leads to rotational vibrations.

• Connecting Rods: Their rotation around the crankshaft can introduce lateral vibrations, though these are typically less significant than vertical ones.

Causes of Imbalance:

• Static Mass Imbalance: Uneven weight distribution in components like pistons or crankshafts can lead to vibrations.

• Cylinder Layout: The engine's design affects how forces from each cylinder interact, influencing vibration patterns.

Balancing Techniques:

• Balance Shafts: These shafts rotate in opposite directions to cancel out certain vibrations, especially in inline-four and V6 engines.

• Counterweights: Adding weights to rotating parts can help balance out forces and reduce vibrations.

• Harmonic Dampers: Devices fitted to the crankshaft to counter torsional and resonance vibrations, enhancing engine reliability.

 Getting this stuff right is the difference between an engine that rattles itself to death and one that runs tight and mean. Proper balancing takes the shake out and keeps the crank, rods, and bearings alive. One of the biggest engine failures—right behind human error—is spinning a bearing. When imbalance lets parts hammer each other, it wipes out the oil film, grabs the bearing, spins it, and kills the oiling in a heartbeat. 

With proper balancing the result is more power you can feel and a motor that stays together whether it’s cruising Main Street, crawling over rocks, running the race, or screaming down the strip.