[Some_Kid]

You are not wasting your money. The whole appeal of metalizer paints(imo) is that it is such a thin layer of paint that it looks like real metal. You may get a better or more reflective finish if you try aluminum plate. But when you use the sealer you only need to put on a very light coat. You don't really need to cover all of it. You could even try painting it and then just try not to handle it too much. Remember that engines get dirty, so adding a black wash will also help.

And tamiya flat aluminum is a great paint for engines. It really just depends on the engine your making. Research the pics of the motor and see which paint will get you a closer finish to the real thing.