I've got a brother doing a 3.8/A4 to a 5.7/M6 swap in my garage right now, and he's ignorant to anything and everything. Anyway...

He bought an underdrive crank pulley and removed the stock balancer and bolted in the new pulley and threw out the stock balancer. I tried telling him that it is CRITICAL for bottom end balancing, but he replied, "then why don't they make an underdrive balancer?" He's an idiot...and won't listen to me.

What's going to happen to this engine? He's got a hotcam/rockers/headers on right now. I know the bottom end won't last for very long...

And no matter what I tell him, he won't listen. Oh well...

 

The crank pulley/damper on the LT1 is not a balancer. But it is still required to prevent damage to the crankshaft from torsional vibration, caused when each cylinder fires, bending the crank throw forward, and then having it whip backwards when the combustion is complete. The "damper" reduces the magnitude of the torsional deflections.

And they DO make integral, underdrive pulley/damper units. ASP makes them.

 

Faster bearing wear?

 

Whats going to happen? A good leson learned and the fact that you tired to help and he didn't listen. you also get to hold that over him for the next time that he does something stupid

 

Let him run it that way, so that we have a DEFINITE answer to "what happens when".

 

To elaborate a little on what Fred said: the harmonic "balancer" will prevent the crank from self destructing. And as 96speed suggested, if the crank doesn't snap, it will be hell on the bearings. All around it's a bad idea.

Rich Krause