Sunfire 2.2 engine bearings

[dubyajayes]

Hi, I have questions about the main and connecting rod bearings on a 2002 2.2 Sunfire. I am doing this work without removing the engine. I have some engine experience (heads, head gasket, etc). I dropped the oil pan, and removed the main and rod caps and bearings. I use a box to keep everything straight and in the correct order. My parts store has "standard" and "oversized" bearings. I mic'ed the old bearings and the caps (used the "wear lines" on the caps; they mic'ed at 21mm. (1) What's the difference? Can I use oversized bearings or do I have to replace everything? (rods, crank, etc) When I removed the mains I noticed that the center bearing halves had no grooves, the rest were grooved. (2) Is that correct? I don't know if this engine is orig or "home rebuilt".
This is kind of a fun project and I'd like it to be a successful one. All help, info and photos would be appreciated.
walt

 

[melsg5]

You are supposed to mic the rod and main journals not the caps. You have to determine if the crank has to be machined. if the crank has to be machined you then use the corresponding oversize bearings based upon how much was removed. Look at the replacement bearing set to see if there should be a groove. Hopefully you have a Hanes, Chilton, or other reference manual to help you with this project.

 

[dubyajayes]

Thanks, I did that too. Apparently the widths are the same, it's the bearing thickness that is referred to as "undersized-oversized". Everything else seems good, now I'm ready to put in the new mains and "plasti-size".
walt

 

[melsg5]

yes the increased thickness of the bearings compensates for the reduced size of the journals.

______________________________

 

[dubyajayes]

Thanks again. I "plasti-gauged" the mains and they look good, between .0015 and .003. Today I'll clean the mains, smear on some STP and retighten. Rod bearings are next.
walt

 

[Roadking_]

what was the reason you are replacing the bearings to begin with? If they were making noise and you don't get the crank re-machined then measured, you will have the noise returning again real soon despite new bearings.

Good Luck
RK