Harmonic balancers

[spetz]

How would an engine be without these?
I know 4 cylinder engines always have bad vibrations at around 3000rpm and need these to "counter act" them.

But what exactly are they? Do they have more weight on one side than the other? And do they have to be checked every now and then that they spin at the right spot with the engine?

[Slow96GSR]

Most manufactures don't do extreme balancing of the rotating assemblies so they put these in to compensate for this. It takes too long to balance every motor they make. They might check every 100th motor to see if there are any flaws or for consistency. The balancers don't need checking except to make sure they're still there. Now in the Honda motors it doubles as the pulley.

www.howstuffworks.com

[LowEk]

they are the wheel that is on the bottom of your engine it drives from the crank it drives your power steering,air cond,water pump etc etc... ill try find a pic just give me a few mins.

[LowEk]

cant find a good pic.

[ECU-MAN]

http://b16a2.kicks-ass.net/tech/b140.jpgthere you go

[spetz]

Thanks guys for that, I knew where they are though...

So, in that case, an engine that is completely balanced (ie taken apart and then balanced), would it still need this harmonic balancer or not?

What kind of weight differences are there between each rotating part in a mass produced engine, as a general figure?

[Slow96GSR]

No, I put a lightweight pulley on that would not help balance the motor. I would make sure that if you are going to swap it out you balance everything, Pulley, Clutch, the rest of the rotating assembly. Then you should be safer. Nothing is ever perfect when it's spinning at 7500 rpm+!!!!