Ok, that would explain the ruined engine. If your cylinder is aluminum and your pistons are aluminum, your pistons or cylinders have to use a coating. Using like materials in both the piston and bore will cause scuffing and a ruined engine. The coating is very very thin on the piston. Once it's been in an engine for a while you can't even tell there is a coating on the piston but you can tell the difference if there is an uncoated piston and a coated piston side by side. The coated piston will look dull and the uncoated one will look shiney. You can not run aluminum bores and aluminum pistons without some type of coating on either one.

Here is more information on piston coatings and the necessity when using like materials in a piston and bore:
http://xrint.com/patents/us/5884600

http://www.mahlemotorsports.com/C125708F0068F67A/CurrentBaseLink/W26MPEHG188STULEN