When installing new bearings there are certain items that require careful attention.
1. All rods, rod caps, and main caps should be marked before disassembly, so that they may be reinstalled in their original postitions. Permanent ink or machinist dye markings are preferable, as hammer type stamps can add potential stress risers and may cause deformation of connecting rods and main caps.
2. Rod and main bearing bores should be inspected with a dial bore gauge to check for out of round or taper conditions that would shorten the service life of the new bearings. Any housing bore that measures out of specifications should be resized. Many professional machinists will recondition all connecting rods and align hone the block as part of their regular engine rebuilding procedure.
3. The crankshaft's journals must be carefully measured and be within manufacturer's tolerances, they must be smooth, and free of burrs. Everything must be spotlessly clean.
4. NEVER use any kind of abrasive pad, cloth, or paper on the bearing surface prior to installation. The overplate layer on an engine bearing may be as thin as .0005", any abrasive used will reduce bearing life.
5.Coated bearings may be "burnished" with engine oil and CLEAN shop cloth.
6. The bearings should be positioned in the rods or main saddles dry, and the bearing surfaces should be lubricated before crankshaft installation.
7. Exercise extreme care when installing the rods. Use or bolt protectors on the rod bolts to prevent nicks to the crankshaft.
8. Bolt threads should be clean and lightly lubricated.
9. Check bearing clearances with Plastigage or dial bore gage.
10. All bolts must be properly torqued to the manufacturer's specifications.
11. The engine should be prelubricated before it is started. Many newer engine designs use a crankshaft driven oil pump that can't be driven by a drill motor.