Is this knock or is the engine just supposed to sound like that?

Is this knock or is the engine just supposed to sound like that?

The second video is from the driver seat, you can even hear the thing backfire and sounds like it gets way too much fuel. The thing was not hot when recording this, but I can say that the oil, even though not in the worst condition, is 6 years old because the car had been standing undriven for 6 years undriven before I bought it. Have driven it pretty hard before this recording and it runs pretty good, idles at 1,000, or just above.