Xtreme57

iTrader: (6)

Very simply as the title says, what causes a spun bearing and how can this issue be avoided?

Thanks guys!

01'SSLSX

well basically some trash(metal) has got caught in the rod bearings and Oil. and the bearing is wearing out. changing u'r oil often and on shcedule can help prevent it, nothing is a garuntee.

SilverSS

iTrader: (30)

usually lack of oil during high rpms. at 7000 rpms along with strong g-force, there might be enough oil in the pan to barely cover the pick-up tube. I always add an extra quart in the pan for just for this.

5150.4.67

iTrader: (3)

^^^^^^^Agreed. Oil delivery problem.

KCS

iTrader: (20)

There are several reasons a bearing will spin, one that not many people realize is the geometry of the housing bore that the bearing sits in. The press fit of the bearing in the housing bore is responsible for holding the bearing in place and keeping the bearing's geometry correct. This is why I cringe when people upgrade their rod bolts in without resizing their rods.

Then, like mentioned, there is an oil film issue. For whatever reason, the journal of the crank can make contact with the bearing and take it for a ride. Anything from a bent crank to excessive blowby can cause this. Preventative maintenance is your first line of defense against such problems.

2002 SS HUGG

I agree that saying bad oil delivery could be a major contributing factor in causing a spun bearing. In fact, I change my synthetic oil every 2,500 miles (Obsessive Compulsive). But anyways, my question is, "would upgrading to a Ported LS6 Oil Pump help with this oil delivery problem?" Just curious with this thread...thanks.

KCS

iTrader: (20)

Probably not, but it shouldn't hurt.

tee-boy

iTrader: (8)

knock can cause it. overheating can cause it (usually leads to knock).

TooLateVTEC

iTrader: (2)

Theres a bunch things that can cause a bearing to spin.

A couple more things on top of whats listes here are, too high of RPM for a long time, gas in the oil, too much clearance between the crank/rod journal and the bearing, etc.

NC98Z

iTrader: (1)

I doubt it. A ported oil pump is gonna drain the oil pan quicker. I believe the only way to prevent oil starved bearings on high rpm motors would be an Accusump. Its acts like an oil reserve until you lose oil pressure or at a predetermined oil PSI. Then it turns loose additional oil to save the engine. I don't own one, but If I was winding the engine past 7,000 alot I think it would be a wise investment.

tee-boy

iTrader: (8)

IF you've got has in your oil, it's time for a rebuild anyways.

tom falco

I am with KCS the hole in the big end of the rod is the culprit if oil supply is sufficient. That is definately why we resize the rods. NEVER replace the rod bolts without resizing. Overspeeding of a bearing is one of the lowest reasons for failure. A rod bearing actually never touches the journal. It is suspended on a film of oil. Oil preasure is not critical unless its to high. That will wash out the bearings. And dirt unless excessive is really not a problem per say. A bearing is designed with embedibility. Dirt particles imbed into the bearing and stay there. (note very very small amounts of dirt and always change oil often) That is why oils are very important. 15-40 oils are designed for diesels that have tremendous shock loads (25-1 CR or better). Oils are the only thing between the crank and the bearing. Hope this helps tom.