Going to be building a very obscure motor (Daewoo/Opel/Aveo E-Tech 1.8L) with my middle school students on a very tight budget. Here's what I have planned so far.
Porting/portmatching the intake and exhaust manifolds. The intake, aluminum, I was thinking about cutting out a chunk of the runners and making it shorter to improve high rpm performance.
Debur the block/polish and balance the rods. I was just going to take my dremmel tool to the rods and balance them on scales. Kill off all the stress risers and hopefully get a little more strength into my mystery cast bottom end.
Build a baffle in the oil tank. During the first track shakedown my engine seemed to push a lot of oil to the head. That has me worried that it will starve the pump if I run higher rpm and/or get better tires. I was going to do with with a welder and scrap metal.
Unshroud the valves and polish the combustion chambers.
Can you think of anything else that's either very cheap or free that will improve the mighty E-Tech?