Why is it we have a problem with these motors spinning bearings,

What actually is causeing these bearing to spin?

What can be done about it?

Is it only a matter of clamping force, bearing design?

 

I don't think it is a "LT1" problem when the bearings get enougth wear on them they will get slack and start "knocking" that is when they spin. by spining one half slides under the other half. in most cases.

 

As far as cam bearing there the same as the ones used in past sbc 1's. Im not sure why theres a more of a tendency for them to spin in the LT1.

As far as main/rod bearings I dont think its as common. I hear retorquing the head bolts can throw off the balance of the crank and cause them spin.

 

might have something to do with the higher redline of the LT1 over TPI setups that only pull to 4,500-5,000 -vs- 5,800-6,500

 

Smokey said that most spun bearings are due to detonation.

The hammering of detonation is transmited through the rod to the bearing, the ends of the bearing draw together and wipe the oil film from the journal, and, well...

 

Nothing different about the LT1 than any other SBC. Look at http://members.aol.com/carleyware/library/ar797.htm for a nice discussion of the causes of main bearing failure.

Rich Krause