i just purchased my tt46 today the manual says its an abn engine from all iv read about this engine in these forums i thought it was an abc engine??

'C' as in composite. Sorry, but YES, it is a nickel plate job on the sleeve. Please keep in mind that the plating is 2-3 times thicker than the nickel liner that OS uses.

Treated properly with the correct break-in and used without overly lean runs this engine will perform very well for many years.