Hi, dumb question, what does it mean to "Balance" a motor?

 

The entire roating assembly (crank, rods, pistons, harmonic balance and flywheel) is balanced as an assembly. Kinda like balancing a tire. Avoids vibration and premature weaar of the engine. Cheep insurance i you are dumping some cash into your motor.

 

It also allows you to spin the engine to higher RPM's, granted you need the proper internals to do this (forged crank, H beam rods, forged pistons, etc.).
-P.

 

Pretty much the same as blueprinting, where each engine part is weighed, shaved to precise weight etc. Some say it makes the parts weaker, but the less vibration and smooth action outweighs any of that.

 

Everyone explained it in generality. I take the rods weigh them. Then which ever one is the lightest I shave material off of the others to match that wieght. I also try to balance the rods, taking the center point and making sure that each one balances. This is not always possible. Then I take the pistons and weigh them and shave them to the lightest piston in the group.

 

you don't want to that yourself unless to have a gram scale the rods acyully have two weights the big end and the little end and its not balanced with just total weight. It is done as follows 1/2* reciprcating + 1*rotating. that gives you the bob weight to balance the crank.

 

Yeah...I use a completely different method. I drop my stuff off at the machine shop and say a magic spell. When I return a week later, my rotating assembly is fully balanced.

 

Yeah I'm the guy in the back who actully makes it balance