1G No Oil to 3 & 4 rod bearings

[DSM Chase]

Replaced my main bearings and rod bearings, bs deleted, had great oil pressure at idle, within two miles it destroyed the thrust and rod 3 and 4 bearings, had enough play to physically move up and down, had Loud knock, rod caps on 3&4 were discolored from getting hot I assume, 1&2 were normal color and no play. Confused I cleaned the entire motor out And had oil pressure how did it kill the bearings?

 

[oh-b-1g]

What were the clearances when you assembled it? Did u plastigage?

 

[DSM Chase]

Factory uncut crank, journals measured exactly per the book, So I used standard bearing size clevites.

 

[95blackGsTurbo]

What was the original reason for the rebuild? You replaced bearings but didn't say why they needed to be done. I would suspect that the tolerances were not correct. Just because it was a factory crank does not mean that the bearings would automatically fit. There is the possibility of debris in the motor but it sounds more like a clearance issue.

 

[DSM Chase]

Spun balance bearing, completely dissasembled and cleaned everything, deleted shafts... I already said the journals miced out with a dial caliper to factory spec.

 

[Mello]

Can't use dial calipers to measure accurately enough on crank & rod journals. Must use micrometers & or bore gauge. Most likely your measurements were wrong.

 

[DSM Chase]

My measurements were EXACTLY what the book calls for on main crank and rod journals? Is that some sort of coincidence how could I measure wrong and get the FACTORY numbers ?

 

[arrowhead]

Did you have the big end of the rods checked, how was the color on the caps the first time.

I think the big end is out of round.

 

[bryanwheat]

What measuring device are you using? Also are you 100 percent sure that you didn't mix and of the rod caps up.

 

[EGLTAWLN]

i think:

spun bearing goo from the balance shaft was hiding somewhere and plugged up or restricted certain oil pressure passageways once the fresh oil pressure got to it.

did you send the block to a machine shop to have it hot tanked? it's very difficult to clean out the complete oil supply at home in a garage.
i screwd that one up before..... now i hot tank everytime i build. paranoia keeps you safe.

 

[DSM Chase]

That could be a possibility but highly unlikely, in the event that they are mixed up how do you know which ones go to which rod.[DOUBLEPOST=1410834122][/DOUBLEPOST]

Did you have the big end of the rods checked, how was the color on the caps the first time. I think the big end is out of round.

Color was normal all 4 caps the same color, no discoloration, I believe it was trash from the previous failure clogging crank passage, now my crank is a boat anchor and likely the rods too.

 

[bryanwheat]

That could be a possibility but highly unlikely, in the event that they are mixed up how do you know which ones go to which rod.[DOUBLEPOST=1410834122][/DOUBLEPOST]
Color was normal all 4 caps the same color, no discoloration, I believe it was trash from the previous failure clogging crank passage, now my crank is a boat anchor and likely the rods too.

It is impossible to tell which cap goes to which rod without using a bore gauge to measure the rod with the cap on it. The best way to make sure that you don't mix them is to remove them one by one and leave the cap on until you are ready to install them one by one, or to stamp the number in the rod and the cap. As for the crank being clogged, i find this unlikely because there would have to be a ton of debris in there to completely clog the passage.

 

[DSM Chase]

True, the motor was cleaned out... Idk

 

[EGLTAWLN]

how long did the motor run after you found it had spun a bearing?
how long did it run on a spun bearing?
how much bearing/oil sludge was in your oil pan when you first took it off?
did you take it to a machine shop to hot tank it?

 

[DSM Chase]

Tore the motor down, never...ever let a friend help install the bearings, the main caps bearings were put on the block side thus blocking the oiling holes...