Blazek already asked valid questions, but I'd like to add a few as well:
- How many fans do you have in your PC? And how are they setup?
Generally you want to push fresh, cold air, into your case, and then have exhausts pushing it out.
- Have you considered an after market cooler? I run a 3600 with a 240mm AIO, and my temps went from 90ish C, to 40-50 C.
Also 80C shouldn't fail your CPU any time soon, 95C is the max as far as I know.
- Under what load does the temp go up to 80C? Or rather, what are you doing for the temps to shoot up? Are you gaming/is the PC idle?
- What are the rest of your specs? What GPU are you using for example?