engine bearings: al_si vs tri metal vs coated

[RoadRaceJosh]

Rod bearings do have more clearance at the parting line normally. The reason being the rod and cap distort and close up the parting-line clearance at high RPM. Real olde tyme engines had shims at the bearings and it was relatively common to re-ring an engine, lap the valves and take shims out of the bearings to keep it going.

Knowing the position of SWMBO makes not pulling the engine understandable. Thankfully my marriage is considerably different in this regard. I got exactly zero grief when I brought home my '64 Avanti in "kit" form. She makes more money than I do and it's my money I'm playing with. At least I got this right the second time around!

 

[Shannow]

Originally Posted By: turtlevette
It took huge ones to make that turbine repair and take responsibility to say fire it up! I know how conservative the power industry is and people with the knowledge and confidence to keep the lights on are few and far between. Kudos to you x100 sir.


Thanks Turtle, I also changed the bearing design in those machines from a silly Parson's bedding system that always showed wipes on overhauls...to a modified lemonbore.

The Parson's design had a shaft diameter +0.002 "seat", with a concentric radial clearance from 8:00 around to 4:00...there was always white metal movement in the 4:00 and 8:00 positions, showing that somewhere in operation the shaft diameter was bigger then the "horns" on the bearing, and the tapered wear showed that it wasn't alignment tolerant.

Lemonbore fixed all that.

 

[Scott_Tucker]

Originally Posted By: Shannow
Originally Posted By: turtlevette
It took huge ones to make that turbine repair and take responsibility to say fire it up! I know how conservative the power industry is and people with the knowledge and confidence to keep the lights on are few and far between. Kudos to you x100 sir.


Thanks Turtle, I also changed the bearing design in those machines from a silly Parson's bedding system that always showed wipes on overhauls...to a modified lemonbore.

The Parson's design had a shaft diameter +0.002 "seat", with a concentric radial clearance from 8:00 around to 4:00...there was always white metal movement in the 4:00 and 8:00 positions, showing that somewhere in operation the shaft diameter was bigger then the "horns" on the bearing, and the tapered wear showed that it wasn't alignment tolerant.

Lemonbore fixed all that.


Is this regarding turbines in power plants? The forces on those bearings are different than experienced in a reciprocating piston engines if that is what you meant.

 

[turtlevette]

I just took this thing downtown. So far so good. I'm still fighting a water contamination of oil problem. So the bearings are working in less than ideal conditions.

 

[Merkava_4]

Just get the ones that say "Sealed Power" the box. You're good to go.

 

[turtlevette]

Originally Posted By: turtlevette
I decided to pin the bearing on the number 1 cap to help prevent another spun bearing.

We will see how long my unauthorized repair lasts. It has 72325 mi.



400 miles so far.

 

[turtlevette]

1000 miles