This is my first time putting together a motor and putting pistons in. Block was bored .04 and new pistons. We checked all ring gaps and they are in spec.

We assembled the motor today and cranked the engine over a few times by hand. What I am noticing is fine scratches forming on the cylinder walls.

We lubed the cylinders with oil and used a piston ring compressor to put the pistons in the block. Here is an attached pic, this is the worst scratch, you can t catch your finger nail on it.



Should I take the pistons out and recheck?

Thanks

 

Was the engine cleaned throughly before assembly? Can't assume the machine shop did a through job. Were the cylinders coated with oil prior to putting the pistons in order to avoid scratches, and was the piston to cylinder clearance verified? From what I can make out only the hone marks have been scratched so that shouldn't be much of a problem.

 

The line looks like it could line up with the diameter of the wrist pin hole. What kind of keepers did you use, teflon buttons perhaps?
Although, that mark does go up pretty high, just a thought that came to me.

 

+1 on what Pete mentioned. I have had more than one block come back from the machine shop "dirty". I always wash my blocks with soap and water and then use compressed air to blow out the water and spray a good coat of WD40 before starting the build.

Did you make certain the the rings were deburred? I have always found a small burr on the edge of the rings after setting the end-gap. If you don't debur that, it will make a slight scratch on the cylinder, although it wears off very quickly.

 

Cylinder walls were wiped and oiled before install, I guess I'll have to take it apart today........

 

Deburr everything....I have ran an engine and never knew it had a scatch and when I decided to change heads I found it. It was deep. But I never had a problem....but it wasn't a new one tho. Look at them ring ends.