So I have my head off and i have a vast ammount of carbon buildup on top of my pistons. Ive heard scraping with a putty knife is a no-no. I also have some carbon on the surface where the valve gasket goes. guidance please
I have scraped a few and blow off with compressed air. If you are still running cast iron pistons,you won't hurt them.
Scrap, scrape,scrape and scrape again. Make sure that you clean up well before putting back together again. Have fun!!!
i used a bog scraper. Also tried a wire wheel on a grinder in the head but it softened the sharp edges where the gasket would go so it might not be a good idea.
I have been told since I was a kid, to scrape them. The use of a wire brush or wheel will leave small pieces of wire and tips imbedded in the pistons and loose in the gap between the piston and cylinder. These small bits will get super hot when the engine starts and cause scratches or hot spots that can damage the motor, a scraper won't. I also use carb cleaner to flush the pistons and clean the residue off. I cleaned the piston tops in my 94 Ranger with 200,000 miles and they came clean as new. As a side note, I could still see cross hatch in the cylinder walls of this great running truck.
Don't fill any carbon crud into the head bolt holes - there were accessory plugs preventing that sold back in the day when kerosene mixed gas made carbon removal much a much more common occurance.
Nowadays you can clean the holes with compressed air and have time to check so the bolts can be screwed down tight without bottoming out
I have found that Lacquer thinner works great! Cleans 'em up like new, non abrasive, and evaporates rapidly.
thanks! They are cast iron for the record.
Just a note. Never a good idea to use any kind of ferrous wire brush on aluminum. Small particles embed and cause a corrosion problem - ask any airframe mechanic.
Brass is ok if its 100% brass.
Here's a set of Stevens Carbon Keepouts I posted a while back under the Accessory Of The Day threads.
Blow out the water passages as much as you can before you put on the head. Then after the head is installed, flush out the block and head with water before you install the radiator. You want to get as much dirt and carbon as possible out of the water jacket so it won't clog the radiator.
A putty knife and elbow grease! Careful to blow out all the residue in the area of the top ring. Make sure everything is clean and squirt a bit of oil in each cylinder before installing head as it will lube the cylinder wall, (on start up) if it was dry from carb cleaner or other cleaning chemicals.
The finish the job and go out and enjoy the ride and have a safe Ride and Safe Day
Happy Memorial to to ONE and all!