Bad piston ring?

[Russ Pottenger]

The scuffing is most likely caused by oil dilution from the gasoline getting past the rings.

[optmaxx]

I'm not too crazy about the scuffing, but there's nothing I can do about it right now. The other cylinders have similar wear, but with no compression loss and plenty of cross hatching. I had the head off before to change the lifters and the scuffing was there, and it looks like there was no in change in wear then vs now; hopefully that's as far as it'll go.

I did try googling stroker piston scuff and some have gone a long time without noticing any compression loss, some say it's normal stroker wear, but some say it's not and just do another rebuild. I was searching stroker builds in general to make myself feel better, but for now, I have no choice but to run them like that. I'm sure that it's not good to have those marks, but how long do you guys think an engine can run like this?

Everything else under the engine looked ok, the bearings looked normal. I also wanted to point out that since changing the lifters, I'm able to make out piston slap noise. Yeah, it's deeper and hollow sounding, but not terrible sounding when warm. I seem to have it a bit when warm when taking off from a stop, but it's a not a hard piston slap, and it goes away quickly as I speed up. It is louder on start up though.

[Cheromaniac]

Took out the piston, both compression rings were toast, the walls look ok. I'm not going to worry about the scuff marks, I'm sure all of my pistons have them.

Yeah, I wouldn't be too concerned about the scuff marks on the piston skirts. They seem to match the vertical marks on the cylinder walls.
Strange that the compression rings failed and it does indeed seem likely that the end gap was too small.

[optmaxx]

Just got done, I've would have been done sooner but I didn't have extra rings laying around like I though; they were misplaced or thrown away. The blow by is completely gone and so is the air puffs from the crankcase, and I'm not sure why they broke. Maybe something went wrong during the break in and they got weak? Hopefully I can get some good miles even with the scuffing, we'll see.