Earlier this year I changed the rod bearings in my motor(92k miles). The bearings did show some wear, but were probably serviceable. What was worrying me was that my oil pressure was way too low at idle and at high RPM, so that is why I changed the rod bearings and the pump.
Now move 100 miles after the bearing change. The pressure at idle was 28~30psi and while at higher RPMs 55~60psi.
So I figured lets go do a shake down run before nationals. I made three autocross runs without any incident. At the end of my fourth run, the oil pressure was zero. I immediately shut down the motor.
I pulled the motor and examined the rod bearings. All were fine except having some embedded particles.
Then I opened the mains. The three center mains spun. A significant amount of damage to the crank and burned oil on the bearings. The groove that is normally in the bearings was filled with "welded" metal. The oil filter was full of metal shavings. Mot just small glitter, but long slices of bearing material.
What causes this to happen? The rods get oil last, so why just the mains?
The bearing in this next photo is one of the rod bearings i.e. the bearing that is not black to the left.
Now move 100 miles after the bearing change. The pressure at idle was 28~30psi and while at higher RPMs 55~60psi.
So I figured lets go do a shake down run before nationals. I made three autocross runs without any incident. At the end of my fourth run, the oil pressure was zero. I immediately shut down the motor.
I pulled the motor and examined the rod bearings. All were fine except having some embedded particles.
Then I opened the mains. The three center mains spun. A significant amount of damage to the crank and burned oil on the bearings. The groove that is normally in the bearings was filled with "welded" metal. The oil filter was full of metal shavings. Mot just small glitter, but long slices of bearing material.
What causes this to happen? The rods get oil last, so why just the mains?
The bearing in this next photo is one of the rod bearings i.e. the bearing that is not black to the left.