dal442

engine builders....

i developed a head gasket leak on my 455. i have tore it down and i am looking at the top of the pistons. looks as if i have accumulated carbon on the top of the pistons.....( stock flat...that i installed 14 years ago with the first rebuild ) here is the question....can i just scrap the carbon....or --- if i use carb cleaner with scraping will i possibly do any harm ? seems the left bank developed a leak just at the back corner....right at the last exhaust manifold bolt..... need just a bit of advise whether i can do any harm to the pistons if i clean them & if using any spray cleaning materials will do any harm ?

i would assume that somebody has some insight....

dal442

oldcutlass

Depending on how much carbon, soaking with brakeclean, carb cleaner, acetone, mineral spirits, etc... and a shop rag usually works well.

don71

That carbon build up is normal.

I see nothing wrong with scraping it off. A sharp gasket scraper or razor blade and some solvent...just enough to do the job.

Don't use scotch brite or sandpaper...ever.

It doesn't have to be dinner plate clean. Just get the largest build areas off.

MDchanic

SeaFoam will soften and dissolve most of it - pour or spray it to soak, then leave it for a day or two and scrape with a soft scraper.
It'll all come off.

- Eric

joe_padavano

If you are pulling the pistons out of the block, oven cleaner is the inexpensive trick for removing the carbon.

Olds64

I can see why you wouldn't want to use sandpaper (the grit could come off and fall into the engine). However, I don't see any problem using a scotch brite pad. Here's a video with good advice, it's not Oldsmobile but worth watching.

MDchanic

I've used fine ScotchBrite along with SeaFoam and a brass wire brush, and it's worked great.

- Eric