From what I can see I think those are just normal flash marks from casting.

I don't think there is anything to worry about.

 

I have to say that the one on the right sure looks like a crack. Casting lines are straight, not jagged like that.

 

There are casting marks from lines in the mold, and flash marks from how the metal filled the mold.

Casting bullets, you see those kind of rippled lines generally when the mold isn't quite hot enough.

Also it appears to be in an area of the casting that I wouldn't think would see much stress.

 

I agree with JeffinTD these are casting lines. Zero doubt in my mind.

Go have fun with your quad, nothing to see here.

 

I'm glad the concensus is that I am wrong.