Wager this statement? I love to tig. I don't have a unit but I did manage this with my buddies miller dynasty 700. He does aluminum foil whenever someone asks. Very very talented kid. Does a lot of roll cages and custom fab.
Pop cans are fun aswell easy with newer machines but like the challenge of welding them together on the 20+ year old synchrowave 250 at work. Plan on getting a new htp invertig 221dv in a few weeks for home. I think it should pay for itself rather quickly.
I have some friends that are really good tig welders. It's practice and time. One of them was a tool and die guy that rebuild molds. Showed the Miller welding rep how to weld magnesium.
Soda cans, foil, and razor blades won't build that bad ass intake for your cummins!! Keep doing what you doing. You can't do anything a 6" Metabo, cutting disks and tiger paws can't fix!
I bought a Miller Diversion 165 and its fairly cheap and its a good welder. I have used it alot. Welded aluminum and stainless and mild with it. Aluminum, limit your thickness to 1/8" for best results. It's also hi-freq so no scratch starting.