changing bearings

[turbokar87]

im installing a used motor that i bought with 90,000 miles on it and when i pulled the oil pan i noticed that the crank bearings are worn out. nothing is damaged, I heard the motor running before i bought it.
i performed a compression and leak down test at my local shop he told me that other than the bearings the block is in great shape.
i dont have enough cash for the shop to change the bearings and install the motor.
my question changing the bearings looks pretty straight foward. unbolt the crank and rods and replace the bearing and torque down the bolts.
is there more to it than that?? do i need any special tools?
and what is a good bearing to use?? ENGINE IS BONE STOCK.
please let em know. thanks guys!!

 

[bryesh]

Do you know how the bearings were wiped out in the fist place?

For a cheap fix and if the bearings are truly the only thing that is amiss, then it would be ok to just replaced them like you are thinking. I think you would be wise to at least plastigage the new bearings once installed to insure proper clearances.

I would make doubly sure that that was the only issue; bearing failure is both indicative and causative of other problems.
Good luck

 

[turbokar87]

there's no damage to the bearings. i think the shop said there discolored like they ran on low oil for a few seconds.

 

[bryesh]

If that was the case then have at it...it's not difficult if you have the engine down this far. Be sure to label everything to install exactly as before and as always, keep everything clean. You will only need basic tools and a torque wrench + plastigauge, unless you have access to micrometers etc. Read up on how to install the rear main seal too, the process is a bit convoluted but doable. Also if you haven't already, you might want to at a minimum replace the stock vinyl timing sprocket with a metal one.

I think most of the auto stores sell federal mogul bearings, nothing wrong with them.

Good luck!

 

[turbokar87]

Ok I'll pick up the engine next week and I'll start taking photos just to make sure.
Thanks guys!

 

[bison]

You need to verify that the bearing bores are in line and round and that the bearing clearance is correct. You will then need to address any problem you find there. Before assembly every plug must be removed and every passage cleaned. Failure to not clean properly will cause bearing material to circulate after start up and it will cause more damage to the bearings. Bearings are not a wear item in an engine. If they wear something is wrong. Putting in new bearings won't correct it

 

[Ttype6]

You'll also need to verify whether or not the crank journals are round or have any runout with a dial indicator.

 

[larrym]

I had my crank polished and inspected than installed new bearing. The machine shop supplied my bearings afterwards and I double checked the clearances when I assembled it.