#3 bearing problem

I just tore down the engine that failed on me at Savannah in Sept, and found that like it's predecessor, the #3 rod bearing had failed. It is obvious that it had gotten extremley hot (looked like some one had taken a torch to the journal). It seem's that the bearing had less than adequate lubrication. I'm now the proud owner of two cranks that have a burnt #3 journal and are best used as a boat anchor.

My question to the wisdom of the list: is this a weak point in the B series oiling system? If so, how does one get around it?
Or is it something I'm doing (or not doing) at the time of the build?

All the other rod bearings are in good condition and show no signs of lack of oil.

Any and all suggestions are welcome

Rick,


"is this a weak point in the B series oiling system? If so, how does one get around it?"

Yes, this is usually where a problem somewhere else shows up first.

"Or is it something I'm doing (or not doing) at the time of the build?"

Maybe.

Questions: Is you oil pan and pump modified, baffled, enlarged? Are you using an Accusump? What kind of hot oil pressure is normal for you engine? Is the crank and block stock in terms of the oiling passages? Which crank are you using?


Barry

Rick, #3 main has to supply all the oil for rods 2&3. At high RPM, the block can't supply enough oil to the crank due to the way it's machined, especially if the oil in the pan is aerated or surging away from the pickup. The fix for the block is too detailed to describe here but call me and I'll walk you through it. 970 564 5822.

I spun a bearing on #3 as well, but I attributed it to overrevving the engine and making the big end of the stock rods look like eggs.