cylinder cleaning question
 

I've taken off my cylinders and am planning on using new rings on my '83 SC. The cylinders are Kolbenschmidt Alusil. My question is how to clean off the top inch on the inside of my cylinder. I assume this area is above the max height of the piston rings and these are mostly carbon deposits from the combustion. Even though I don't plan on changing the height of the cylinder/piston I'm concerned that if the ring does hit this area it will damage the rings.

Is this something I need to worry about and if so what is the best method of cleaning them? I plan on cleaning/honing the entire cylinder bore with the grape hone and scotchbrite pad as described elsewhere in the forum but I didn't know if this would also take care of this top inch.

Thanks,

Dave

http://forums.pelicanparts.com/uploa...1356895748.jpg

research alucil. its not something you hone or rering.
Bruce

Seems like plenty of people have had success as documented on this forum, especialy in this thread:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/137346-re-ring-alusils.html

never grape hone them. they'll be ruined. a light scrub with scotch-brite if anything at all. a new razor blade takes off the carbon. lay it almost flat and shave it off.

John - do you recommend any paste on the scotch brite pad like the silicone paste mentioned in some other threads or just dry?

At the risk of giving you enough information to make your head hurt, at least if you try to read it all at once, read the thread linked below. Right off the bat, I don't know how applicable it is to Alusil, so proceed at your discretion.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/163663-do-i-need-hone.html


I would kindly ask that what ever way you decide to go, please post updates periodically to let us know how it's going. I believe that would be useful information for the board. Thanks.

Never touch an Alusil cylinder with a ball hone. You can re ring the cylinders, to prep simply use dishwashing liquid and the scotchbrite pad on the back of an old dishwashing sponge. You are not trying to score the surface, you are only trying to clean the surface well. Also check piston ring clearances closely, I cannot tell you how many times I have seen "factory trained" techs throw on a new set of standard size rings without checking ring gaps, this is a travesty.

You can use special engine cleaning liquid which dissolves the residues without rubbing it hard. The liquid that we use over here is called "Turbo" (made locally by a chemical company)and is meant to clean engine parts. It's pH is ~13 and around 1 hour is enough to soak the part in it when mixed with water in 1:1.
It made my RS pistons and cylinders look like new.

I used a razor blade as John Walker suggested. Between the blade and carb cleaner and scotch brite pads I was able to clean them quite well without any damage.

I'm cleaning the entire cylinder bore with scotch brite pads and depending on how they look will try the felt pad/sunnen an-30 paste method on the end of a 3 arm hone. The cylinders only have 85,000 miles on them and are generally in very good shape (in spec and no scratches). I had to replace one cylinder that was damaged and the replacement also looks to be in very good shape.

My heads are coming back from the machine shop this weekend so I hope to be putting the engine back together shortly following Wayne's book.