how do u know by lookin at the crank that those prosedures have been done to it or not

 

you can't just balance a crankshaft - you have to balance the entire rotating assembly - crank, rods, pistons, pins, etc.

 

ok how can u tell with all that

 

With a 4 cyl, you can just balance the crank only. Look for freshly drilled holes on the crank counter weights.
As to micropolishing, the crank journals will shine like a mirror

 

*just to help* and the benifits are....

 

balancing your rotating assembly allows for smoother operation which increase reliability.

 

Best way to balance is start with the crank only. Then add the flywheel and balance, add pressure plate and balance again. Then last but not least, add the crank pulley and balance one last time. Unfortunately, there's no way to tell by looking at a crank if it's balanced or not. Yes you may see new looking drilled holes or ground off marks but does that tell you that it was balanced correctly? I think not.

Only way to know for sure is mount it up on one of these.

 

what about the polishing? I've been debating this for awhile and am not sure if it is really that benificial... any thoughts?

 

Polishing the crank is to make sure that the matting surfaces of the bearings to the journals are as smooth as possible. Think of how much preasure there is on that part of the crank (main/rod journals). Say ou are making 200bhp out of a 1.8L engine. I would think that the forces generated on the on the journals by the piston pushing the rod down on top of the crank turning it over at 8-9,000 times a minute would be pretty significant. Now think about the oil, it heats up and tends to get pretty thin about this time ( not to mention how thin the layer of protection is during normal operation), if you have even the smallest little nick or sratch on the surface of one of those journals that could turn out being the life or death of that bearing running across it hundreds of thousands of times a day. You can take it from here as I am sure most of you know what the outcome of a scored or seized rod/main bearing are.