question about rings

[mcglsr2]

do you guys know of any *reasonable* way to determine if rings are good with the cylinder head off? i've got the head off for other reasons, and i would like to check the rings - i think they are okay and i would really rather not screw with them if they are okay. car was burning a little oil, but i suspect the cylinder head. still, it would be nice to know it's not the rings if possible. the engine has about 160K miles on it, Mobil 1 synethic it's entire life.

thanks!

[puppet]

You can check several aspects of the pistons while the head is off ... pulling the pistons is required, obviously. Most of the examination will be telling you about the condition of the pistons however.
You can check side clearances. That's the width of the grooves with rings installed.
You can determine if the ring lands have beveled. That's where the groove itself is worn in such a way as to not be perpendicular to the piston body.

Basic cleaning of the grooves and rings can help .. especially the oil control pack. You must keep a record of position though ... providing they are going back in. Frankly though, if you've gone this far in the process I'd just get another set of rings. Don't forget that 160,000 miles has worn the diameters down some. End gaps have increased and you will see a bit more blow-by and oil consumption as a result.

Hit up your machinist to see what he can score a set of moly Hastings for ($). They aren't too much as I recall. My guy had some laying around and sold them to me for $30 or so. Get a new set of rod bearings then, too.

[turbovanman²]

Easiest way to tell is look at the piston tops, if they are covered in carbon etc and no clean spots, then suspect they are ok. If you have clean area's at 12 and 6 oclock, then you need a ring job.

[mcglsr2]

here are some pictures of the tops of the pistons. please take a look at them and let me know if you think anything looks abnormal about them.

the first one shows all 4 about half-way down the bore:
http://i98.photobucket.com/albums/l248/mcglsr2/Shelby/Engine%20Bay/Pistons/allfour.jpg

this is cylinder #1, perhaps a little troubling. note the red circle:
http://i98.photobucket.com/albums/l248/mcglsr2/Shelby/Engine%20Bay/Pistons/cyl1.jpg
that is a pitt, a little hole in the piston face - it doesn't go all the way through the piston, it's only like 1/16" deep (maybe 1/8" at the center). what is that? is that from detonation? do i need new pistons or something?

cylinder #2:
http://i98.photobucket.com/albums/l248/mcglsr2/Shelby/Engine%20Bay/Pistons/cyl2.jpg

cylinder #3:
http://i98.photobucket.com/albums/l248/mcglsr2/Shelby/Engine%20Bay/Pistons/cyl3.jpg

and lastly cylinder #4:
http://i98.photobucket.com/albums/l248/mcglsr2/Shelby/Engine%20Bay/Pistons/cyl4.jpg

so what do you guys think? do they look about like they should for 160K mile pistons?

thanks!

[turbovanman²]

That dimple is the mark done by the manufacterer to point forward-aka the timing belt, ;)

Apart from 1 showing alot of oil, IE guides and 3 showing some, I'd say they look fine, fix your head and be done with it.

[mcglsr2]

That dimple is the mark done by the manufacterer to point forward-aka the timing belt, ;)

ah, i guess so that they know the valve reliefs in the piston face are facing the correct direction. that's good to know :)


Apart from 1 showing alot of oil, IE guides and 3 showing some, I'd say they look fine, fix your head and be done with it.

yah, pretty obvious which was burning oil. i was hoping you would say the head. just so happens i have a ported one ready to take the other's place. thanks so much for the help :thumb:

incidentally, i had carbon buildup in the #1 and #3 exhaust runners - looks like form the oil the cylinders were consuming...which matches what you said above about #1 and #3