Cleaning carbon off pistons in car?

[07-SRT]

So while Im waiting for my heads to come back, I decided to clean the pistons..I started with one piston at thr top of the block using brake cleaner , wd40 and plastic putty knife. Now I'm wondering if I should leave the other 7 alone due to solvents getting past the rings into crankcase and or debris getting caught in the bore.......Should I continue or stop and why?
Am I just being paranoid and over thinking?

[hammdo]

Originally Posted by 07-SRT

So while Im waiting for my heads to come back, I decided to clean the pistons..I started with one piston at thr top of the block using brake cleaner , wd40 and plastic putty knife. Now I'm wondering if I should leave the other 7 alone due to solvents getting past the rings into crankcase and or debris getting caught in the bore.......Should I continue or stop and why?
Am I just being paranoid and over thinking?

Chevron techron works well. I used all types. Just clean it well afterwards...

Leave the old oil in while cleaning. When ready, change it out...

-Don

[appleman22]

b12 chemtool is cheap and works wonders, it literally makes the carbon melt off. Then just change the oil after you mount the new heads and whatnot

[07-SRT]

^^^ My plan was to change the oil after everything was together and bring oil temp up to at least 212° and then change oil again... ..

[BFASTNOTLAST]

My OCD took over when I fly-cut my pistons so I had to clean them.... I simply used a razor blade and scraped it off dry, then vacuumed it clean. Take your time and use a blade holder to make it easier. Mine had 60K on the clock and it took a few minuter per piston. You will gouge the piston if you are too aggressive on the angle your holding it so beware. They came out looking new when I was finished. Take your time.

[BFASTNOTLAST]

[Russell James]

Carbon on piston tops is meaningless, leave it alone. Carbon in the ring grooves and bearings is a motor killer.

Next time a motor is apart, lay a hair across a main bearing and retorque the cap. See how the motor is now locked solid? That how small a something can fudge things up. And carbon bits are big somethings.

Another big factor .... stuff is really really tight fitting.

Another big factor .... tri metal bearings with a lead layer that self repairs all those little crud scratches....thing of the past. Thanks to environmental Nazis, modern OE bearings are aluminum and extremely damage prone.

Another big factor ... the ittiest bittiest piece of carbon crud can stick the oil pump relief valve.

Another big factor ... the filter doesn't filter 100% of the time

....need I go on....

If you want to keep the motor relatively clean, put a bottle of techron top engine cleaner in a full tank of premium. Run that tank, floor it a few times after about 3/4s of that tank is used up. Then change the oil.

That method will slowly melt away most of the carbon and not put little chunks everywhere.

Even if you don't do that, that little piston carbon is meaningless. If a scanner shows a lot of KR on 93... time for a tank of techron. No preignition, do nothing.

[Elite Engineering]

"The carbon contributes to abnormal combustion in several ways, but the most dramatic effect in a modern fuel injected engine is the "sponge effect". As the fuel mixture in the cylinder is compressed, the carbon has a tendency to absorb both oxygen and fuel. Once the ignition spark fires, the flame front normally spreads through the chamber, consuming the fuel and air, however, the carbon has a tendency to extinguish the flame front and stifle combustion.

This, combined with the fuel and air that was absorbed, results in poor efficiency. As the chamber decompresses during the exhaust portion of the stroke, the unburned fuel and air is released, resulting in both excessive fuel and air (containing oxygen) entering the exhaust system. The O2 sensor detects the excessive oxygen and the vehicle computer (ECM, ECU, PCM) compensates for this by enriching the mixture."
Other issues are it allows for "hot spots" of glowing carbon that can pre-ignite the air/fuel mixture causing increased incidence of knock retard. In any case, it is bad to have any carbon build up or coating on the piston tops.

Do most people never realize the degradation caused by this? Yes. As any degradation in efficiency and power as a result is gradual, most will never realize until AFTER manually cleaning these deposits. Just as the valves in the engine were designed to always be 100 free of deposits that disrupt flow, heat transfer, and efficiency the same is true for pistons.

[Russell James]

Originally Posted by Elite Engineering

"The carbon contributes to abnormal combustion in several ways, but the most dramatic effect in a modern fuel injected engine is the "sponge effect". As the fuel mixture in the cylinder is compressed, the carbon has a tendency to absorb both oxygen and fuel. Once the ignition spark fires, the flame front normally spreads through the chamber, consuming the fuel and air, however, the carbon has a tendency to extinguish the flame front and stifle combustion.

This, combined with the fuel and air that was absorbed, results in poor efficiency. As the chamber decompresses during the exhaust portion of the stroke, the unburned fuel and air is released, resulting in both excessive fuel and air (containing oxygen) entering the exhaust system. The O2 sensor detects the excessive oxygen and the vehicle computer (ECM, ECU, PCM) compensates for this by enriching the mixture."
Other issues are it allows for "hot spots" of glowing carbon that can pre-ignite the air/fuel mixture causing increased incidence of knock retard. In any case, it is bad to have any carbon build up or coating on the piston tops.

Do most people never realize the degradation caused by this? Yes. As any degradation in efficiency and power as a result is gradual, most will never realize until AFTER manually cleaning these deposits. Just as the valves in the engine were designed to always be 100 free of deposits that disrupt flow, heat transfer, and efficiency the same is true for pistons.

Sure, getting rid of that carbon is a good thing. Preventing it is a good thing. But this topic was scraping it off while the pistons are still in the hole. Horrible idea.

Unless you can surgically separate/block off the piston top from the rest of the engine... those little bits flying everything will do far more damage than that little bit of piston top carbon. I've seen the sponge effect on intake valves that are so carboned up they look like cauliflower. Mostly DI motors or any engine with oil way too old/sludge. But a properly maintained LS motor.... that piston top carbon is meaningless.

I had a '10 LS3 that I took the heads off at 3000 miles to do a cam/lifters. Heads and piston tops were surprisingly carboned up. Cleaned the heads, didn't touch the pistons. I'd been taking it pretty easy on that car. 20,000 miles later took the heads off again to change the cam back to stock for a trade in. Pistons were cleaner at 25,000 miles than they were at 3,000. Conclusion.... just need to drive it harder to blow that crap out naturally. In the first 3K, even had a catch can on it, changed synthetic oil twice...... just got quite a bit of carbon from too much putzin around easy.

Yeah carbon is a bad thing. Scraping engine parts while still assembled is worse. I've seen what that does to cylinder walls, rings, and today's junk aluminum bearings.

[GONIF]

Pour a can of Seafoam on them ,let it sit overnight and wipe off the tops of the pistons in the morning. Seafoam will eat the carbon and not hurt anything. Great for cleaning firearms as well.

[07-SRT]

I have done 2 like this....I dont see how any carbon can can get past the first ring?or wedged in there? It took about 1.5 hrs to do 2...Maybe I'll try seafoam next
http://www.camaro5.com/forums/attach...1&d=1488931812