: How do you clean ring grooves on pistons?



eyewonder
05-03-12, 03:29 PM
My 2000 STS engine is apart, waiting for me to get things clean for reassembly. This includes new rings. The old groves are all yucky looking with baked-on oil, etc and I would like to have them clean for the new rings.

I did not, and don't want to use any type of scrapping or metalic wire brushes, etc. I tried cleaning one piston using an ultrasonic cleaner that I built, with some solvent for the liquid. Let it work for 4 hours. It did succeed in making the entire house smell like solvent, but didn't clean the piston like I had wanted.

My next thought is going to the local car wash & blasting the pistons with the high pressure washer. The next thought would be to go buy some carburetor cleaner (liquid in the gallon cans) and dip the pistons in there, one at a time.

What are methods you have used that gave good results?

Cheers,
Steve

JoeTahoe
05-03-12, 03:39 PM
i have always taken and old ring and broke it in half, then use the factory end (were the ring gap would be not the broke end) and just gently pull the ring threw the gap. Be careful if you use this methed the rings are very sharp.

eyewonder
05-03-12, 03:47 PM
I have thought of using that sort of technique, but was (am still) concerned about taking away 'piston' instead of the baked-on oil that I want to get rid of.

I will keep that as a possibility, but will probably try the car wash thing tonight after work.

Cheers,
Steve

98eldo32v
05-03-12, 04:05 PM
Buy a can of Gunk carberutor cleaner, set the piston in the gunk four a few minutes/ hours. Let the solvent dissolve the baked on oil/grease. If need be, use an old ring to clean out the groves, carefully then on to next piston.

bill buttermore
05-03-12, 04:10 PM
I have always used a piece of the old ring that came out of that groove as Joe described. I can almost assure you the high pressure car wash will mostly make you wet, while doing little or nothing to the carbon in the grooves.

There is a commercial product called Piston Kleen that makes a lot of claims. If you try it and it works, let us know.

There is a tool made for the purpose, but they are awkward to use.

rodnok01
05-03-12, 04:26 PM
Don't bother with car wash. Either buy a ring groove cleaner(15-20 ) or do as others have said and use an old ring. If you get some carb cleaner you can bag the piston to let it work better if you only have the spray kind.

Submariner409
05-03-12, 07:28 PM
Old, broken ring and common sense. Dirty deeds done dirt cheap.

Ranger
05-03-12, 09:40 PM
http://www.google.com/search?q=piston+ring+groove+cleaner&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
There is a tool for every job, but the broken ring is cheaper.

eyewonder
05-03-12, 10:01 PM
OK, trying to keep things straight and understand. Several posts have indicated that wire brushing the top of pistons is bad ju-ju. OK, I can deal with that. You don't want to start small scratches in the piston that turn into BIG scratches, and possibly big pieces.

Way back-in-the-day when working on small- block chevys, we used to use a ring groove cleaning tool, similar to the ones in the above post. That tool actually cut into the piston when cleaning out the carbon, just a small amount, but it was cutting aluminum piston. If that is the case with the current tools, that would be putting more stress risers/cracks in the grove. Which doesn't sound like a good thing.

There must be something I am missing.

And by the way, I tried the car wash on one piston tonight, and it did a reasonable job. I would probably feel good about using that piston, as is.

Cheers,
Steve

bill buttermore
05-04-12, 12:00 AM
O.....And by the way, I tried the car wash on one piston tonight, and it did a reasonable job. I would probably feel good about using that piston, as is.

Cheers,
Steve
Well, spray me down and make me cleaner! Thanks for letting us know how it worked.

stoveguyy
05-09-12, 09:52 PM
New rings,bearings, oil control plate sounds nice but I would be somewhat bummed that motor was so crudded up to start with. Sure, any motor can be freshened up but if motor has 100k miles and looks like hell inside than it was probably abused. Or not.

Submariner409
05-10-12, 09:20 AM
Have you ever overhauled a typical American daily driver internal combustion engine with high mileage ?? (75,000+) Even with regular maintenance and oil/filter changes the entire inside is a light tan to brown color from oil contaminants, the piston crowns are covered with a .010" layer of "carbon", valves are dirty, EGR passages are filthy, bearings are worn, seals are hard/cracked, valve guides may be worn, valve seals are on their last legs, valve springs are no longer useful, hydraulic lifters and/or cams are probably well worn, piston rings/grooves are filthy - the list goes on and on, but every bit of it is perfectly normal.

The fact than an engine even runs and supplies motive power is a miracle in itself, but combine that with burning thousands of gallons of gasoline and some wild amount of lube oil in a metal-to-metal high temperature/pressure environment and it's a wonder the thing goes past 100 miles. Back in the 50's most European cars came with an Owner's Manual that fully explained how to "decarbonise" an engine - top overhaul - and it was done by the owner every 6 months !!! Truth. And we now rely on lights and messages because NO ONE ever looks under the hood or at the brakes until something lights up and says "HELP !" for the car. "My Cadillac runs forever and doesn't need maintenance. It's a Cadillac...." Yeah, right.

stoveguyy
05-13-12, 09:57 PM
why is motor tore down? headgaskets? you don't pull pistons to check rings cuz your bored. oil consumption issue?

Faded Crest
05-14-12, 11:50 AM
why is motor tore down? headgaskets? you don't pull pistons to check rings cuz your bored. oil consumption issue?

He's basically in the middle of a rebuild prompted by head gasket failure. I think there are 4 of us right now doing similar projects.

eyewonder
05-14-12, 01:29 PM
why is motor tore down? headgaskets? you don't pull pistons to check rings cuz your bored. oil consumption issue?

I intentionally got this car, good body & interior, with bad head gasket, so that I could repair the engine & have a nice car. The first inclination was to just repair the head gasket problem. After getting the cradle out, the engine was completely covered in oil, everywhere. I tend to keep a car for at least 10 years, so I wanted a reliable car.

So .... in for a penny, in for a pound. Thus the full rebuild.

Cheers,
Steve

stoveguyy
05-17-12, 11:43 AM
Ok. Yes I have rebuilt motors. I agree new bearings, rings, valve stem seals is nice. But for who? U will have this car for 10yrs? I would really hate to pay for new cams and stuff on a north star. I replaced a valve cover gasket this spring and dad helped. He said cam lobes had a little wear. He said new cams would fix it right up. Ya, sure. Who pays for that?