Used Shortblock Prep

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mopowers

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How do you guys clean the carbon off of the top of pistons and clean the block deck surface on an assembled used shortblock? Is a wire wheel or scotch bright roloc too aggresive?
 
Well, I personally don't let scotch brite get near any short blocks of mine. They "dust" all over fine particles that can score bearings, etc. I prefer a wire wheel.
 
Wire wheel...NO!!!!! Never use a wire wheel to de-carbon a piston top! One of the first things we learned in auto shop.
You can soak the domes (upside down) in de-carbonizing fluid and after it softens, scrape it off with a plastic or nylon scraper followed by light use of a Roloc as needed. Use a ring grove cleaner (available from Summit, etc) to clean the ring grooves.
 
PB blaster and a nylon brush after I hit the crust off with a paint stick
 
Use a wire wheel on an angle grinder on the deck. I like to use a razor blade scraper on the piston tops to carefully scrape carbon off, then blow it all out good with an air blower.
 
You guys are all crazy, WD40 in a bowl if the piston is out of the block, stick it up side down over night and pull it out and wipe it clean with a rag. if it's in the block soak rags in WD40 and stick in the bores and let it soak, you can wipe it off with a rag. Cleaning throttle blades in throttle bodys same way, in a couple hours the throttle plate is clean. I do it all the time.
 
You guys are all crazy, WD40 in a bowl if the piston is out of the block, stick it up side down over night and pull it out and wipe it clean with a rag. if it's in the block soak rags in WD40 and stick in the bores and let it soak, you can wipe it off with a rag. Cleaning throttle blades in throttle bodys same way, in a couple hours the throttle plate is clean. I do it all the time.
WD40 works great, used it for everything before PB came out.
 
Wire wheel...NO!!!!! Never use a wire wheel to de-carbon a piston top! One of the first things we learned in auto shop.
You can soak the domes (upside down) in de-carbonizing fluid and after it softens, scrape it off with a plastic or nylon scraper followed by light use of a Roloc as needed. Use a ring grove cleaner (available from Summit, etc) to clean the ring grooves.
If we’re talking a caveman type who only knows to jam the aluminum piston into the coarse wheel as hard as he can because the carbon comes right off fast well yeah, not a good idea. If one knows how to finesse and use a little brain it’s fine. Done it plenty of times with no signs of wire being used on the tops.
 
Rolocs remove metal....if you want a wavy deck go for it. Never thought it did this until one if my machine shops showed me..
 
Rolocs remove metal....if you want a wavy deck go for it. Never thought it did this until one if my machine shops showed me..

It also put microscopic silicone particles in your motor that is very hard to clean out, might as well through some sand in there when its done, you know just for good measures, LOL
 
What i would actually DO would be to clean the block deck off with a wire brush on an angle grinder and blow it off really good like I described and leave the pistons alone. Put it back together and get it running. If the carbon on the pistons really bothered me that bad, and it probably wouldn't but if it did, I would dribble a coke can full of water through the carburetor slowly at about 2500 RPM. Instant cleaned pistons, valves and chambers.
 
What i would actually DO would be to clean the block deck off with a wire brush on an angle grinder and blow it off really good like I described and leave the pistons alone. Put it back together and get it running. If the carbon on the pistons really bothered me that bad, and it probably wouldn't but if it did, I would dribble a coke can full of water through the carburetor slowly at about 2500 RPM. Instant cleaned pistons, valves and chambers.
Not to mention the fact that after 1000 miles they are all carboned up again.
 
Exactly, so the coke can trick is really only temporary and to make you feel better. lol
I remember doing that to my 318 in my 72 Barracuda back in 1983. I thought I was hot **** with that carbon cleaned up, but that poor thing would still barely break one tire loose. Wish I knew then, what I know now.
 
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Bought a late 80's Camry with a ticking noise. I use a squeeze type ketchup bottle with water into a vacuum line. Cured the tick.
 
I remember doing that to my 318 in my 72 Barracuda back in 1983. I thought I was hot **** with that carbon cleaned up, but that poor thing would still barely brake one tire loose. Wish I knew then, what I know now.

It's a very good fix for one with heavy carbon from put putting around town. I've blown out huge chunks of carbon and crap out of one before. It works good in that instance.
 
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Years ago I used some stuff called Slick50 fuel treatment in my W200.
It said on the can " cleans from the tank to the tailpipe " and it did, clean as whistle.
 
It's a very good fix for one with heavy carbon from put putting around town. I've blown out huge chunks of carbon and carp out of one before. It works good in that instance.
Carp huh? Never seen carp blown out the exhaust pipe before....you say you’re from Georgia?:lol:
 
If we’re talking a caveman type who only knows to jam the aluminum piston into the coarse wheel as hard as he can because the carbon comes right off fast well yeah, not a good idea. If one knows how to finesse and use a little brain it’s fine. Done it plenty of times with no signs of wire being used on the tops.

used wire wheel many times on flat tops pitsons and cleaning the deck...
used Easy Off to....
 
used wire wheel many times on flat tops pitsons and cleaning the deck...
used Easy Off to....
Yessir, with the wire wheel you just don’t lay into it, only so much pressure using care I’ve never left any signs of wire use on the piston tops. Scraping with a flat tool? That’s a different story.
 
Yessir, with the wire wheel you just don’t lay into it, only so much pressure using care I’ve never left any signs of wire use on the piston tops. Scraping with a flat tool? That’s a different story.

Not with a razor blade. You have to use finesse.
 
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