I know a lot of carb'ed engines, vintage racers, etc... will run without air filters. But they don't have MAF sensors, O2 sensors, catalytic converters, PCV's... etc.If it makes you feel any better, I had absolutely no air filters on my BMW for like 5 or 6 years of daily use. Just wide open velocity stacks on Weber sidedraft carbs, trying to kill that engine. It never died, and eventually tore it down for upgrades, and the machine shop thought the engine was low mileage. Filtered air is overrated.