I, too, have read about using acetone but have not tried it. The article I read did specify that it needed to be what is considered "pure" acetone, not just any.
I believe this is the article on acetone that I read.
www.pureenergysystems.com/news/2005/03/17/6900069_Acetone/ Here is an interesting article on cutting a simple groove in the head portion of a combustion chamber to improve performance and fuel economy.
http://somender-singh.com/component/option,com_frontpage/Itemid,1/
The groove cutting does make some sense and is simple enough to do with basic shop tools. Anyone willing to sacrafice a head in case it doesn't work?
