I give you pics, you give me opinions

[bigjangin]

http://students.washington.edu/jlhobbs/car/ouch.jpg
http://students.washington.edu/jlhobbs/car/ouch2.jpg

Tell me what you think. Typical of a high mileage dsm? Or looks like something bad happened?

 

[BoostinAWD]

Looks like I'm seeing factory crosshatchings?

 

[GotSome-Turbo]

It looks like it's been running lean/ with knock by the piston tops, oddly however the cylinder walls look to me like they've been freshly hooned? by the swirls, I'm surprised with the way the piston looks they're not pitted, then again it might be the photo?

 

[x camaro owner]

the pic is kinda of hard to tell from. but over all the motor seemed to be average runnning a bit lean, at first glance i thought there could be a broken compression ring but a closer looks seems to show the vertical lines on the cylinder walls are not gouges/deep scratches, the swirl is normal to look like it was just honed, on a motor that gets oil changes they will always stay like that, i have taken apart motors with 200k miles on them and they still have there honing swirls. as for the vertical marks hard to say with out seeing it in person, the glare of the light is tricky

 

[GotSome-Turbo]

Just clarify, I just meant I was surprised to see the cylinder wall looked fairly fresh, while the pistons looked so bad, but like you said it could just be the picture.

 

[bigjangin]

the pistons just have alot of carbon buildup. The vertical lines are scratches. How common/normal are those scratches?

 

[x camaro owner]

your always going to have some vertical lines never seen a used motor with out them yet. i am sure yours has them to

 

[apache211]

I recently removed a 1g gst motor outta a junk car and it had 220,000 miles on it. The cylinder walls were beautiful, smooth and no problems. It has the same markings on the walls as yours does.... the 4g63 is a tough block, i don't think you have anything to worry about.... hope this helps...
-adam

 

[1fast97gsx]

yea some verticle lines are normal. When they get to be deep is when you will have the problems. Oil will pass by the lower oil ring and go up to the spark plug and blow out the spark. It could also cause slight loss in compression. I would have those scrathes checked out if you are doing a rebuild on it and possible have those taken care of. It depends on your budget and what your reasons for the rebuild are in the 1st place.

 

[bigjangin]

what is meant by "deep." How do you tell deep scraches from less serious ones.

 

[1fast97gsx]

a machine shop will be able to tell you ... they use a feeler guage and they can measure it. I recommend taking it to a shop and having them measure the scrathes. If they are too deep to hone out have the block bored .020 over and then have it honed again. It'll be like new.

 

[awddsm95]

the honing looks good, as for the scratches, if u can run your finger nail over them and not snag it, its fine, i would clean the tops of the pistons with a wire wheel on a power drill or air tool and throw a new head gasket on, make sure its clean when u put the head back on, use some brake parts cleaner (good cleaner, no residue)