Engine center bearing

[daren007]

I have a model "A" with the center bearing breaking up into small pieces about 3/16 by 3/16 kind of like flakes. These pieces managed to get between the good babbit and the crank pretty much preventing the engine from turning. Any help on what could be the cause?

[J Franklin]

Bad babbit or bad lubrication.

[Kurt in NJ]

Crummy Babbitt---- cook too long, cook too hot, reusing old Babbitt

Take a sample and bend it, original Babbitt bends a ways before breaking, old reused overcooked Babbitt shatters

Not peined gets pounded, too brittle to conform,

Dirty pour, then blow holes filled with solder

[daren007]

I thought I read somewhere that certain engine loads could be damaging to main bearings. I this just a fairy tale or is there some truth to this.

[J Franklin]

Good babbit with proper oiling, cooling and clearance can take the load. Lugging the engine can lead to a broken crankshaft.

[pbishop]

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AVOID 'lugging' whenever you can - I would 'always' rather slightly over-rev the engine instead. 'Lugging' is like taking a hammer to all the bearings, the meeting points of moveable engine/trans/drive-train parts, and any 'fitted' points on the car. Think of it like someone repeatedly picking you up and just shaking your body up-and-down and all around.

[Kohnke Rebabbitting]

Originally Posted by daren007

I have a model "A" with the center bearing breaking up into small pieces about 3/16 by 3/16 kind of like flakes. These pieces managed to get between the good babbit and the crank pretty much preventing the engine from turning. Any help on what could be the cause?

Is it new babbitt, or old babbitt. Take some pictures.

One thing about the center main. once it has wore loose, and you reset shims, and clearance, and the front and rear was taken up much less, the crank now is out of Alignment, in the center main, and there is always one side of the crank that is exerting more pressure, then anywhere else, on the rest of the main journal. The force is coming from the flywheel trying to bring the main journals back to a straight line. This can't be done, so the center main pushes hard in one spot, circling the center main, pushing, and cleaning the oil ahead of the tight spot, and robbing the rest of the crank, and main of oil.

So with out a protective oil film, the top surface say .010 of the bearing builds heat, and softens, and if it doesn't take the main clear out, the now rotten surface babbitt, will flake, because it has melted it loose, and welded back on, but very poorly.

Herm.

[Kohnke Rebabbitting]

Think of it like someone repeatedly picking you up and just shaking your body up-and-down and all around. " END QUOTE "

My Girl friend does that to me when she is out of Cigarettes, and looking for quarters!

Herm.

[daren007]

Herm that is what I was looking for. This is babbit possibly original. Someday when I have the patience I will figure out the picture thing but for now this is what I have found. The crank is standard with little wear however the mains have about 1/2 thousands taper and 1/2 to 1 out of round. Someone has been into this thing. It looks like they tried to re-melt something back into the bearing "babbit or whatever". A lot of work to save a lot of money but a failure. Daren

[Tom Wesenberg]

Originally Posted by Kohnke Rebabbitting

Think of it like someone repeatedly picking you up and just shaking your body up-and-down and all around. " END QUOTE "

My Girl friend does that to me when she is out of Cigarettes, and looking for quarters!

Herm.

You need to shake her up for smoking. LOL