85C is safe. Anything below 95C but some other solutions can also help. How open is the case? Is the air not sufficating? (Enough fans pulling air in or out).
The Noctua L9i is only a 65 watt TDP and the 7700K is a 91watt so its a little small. As long as you arent thermal throttling then its fine but your i7 7700k CPU will naturally run on the hotter side.
You will need a tower cooler with a 100watt+ TDP if you want to overclock or have your CPU temps lower.
I had the same problem with my ryzen 5 2600.On stock cooler she would go up to 82c when gaming.I got myself a coolermaster ML240L rgb cooler and in summer she doesn't go over 40 when gaming.In stress test she goes i think around 62-70c cant rem exactly.When i oc her to 4.2ghz she goes to 82c on a stress test.I personally would never go back to air cooler.Only reason why i went with aio is cause my case depth are only 160mm and all the coolers here are 165mm+