I was running 60 and 70 percent of cores and cpu times and temps of system was in 80's. It started to get hot with fans roaring and found that there were various cores that flashed hot....even running at 20 per cent cores and 20 percent cpu....cpu temp bounces from 50 to 98 degrees.....any ideas

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Well, there's the obvious one: Clean out the dust.

But some more info would help:
Is it a laptop, or desktop, is it out in the open, or in a closet, etc.

Worst case: the thermal paste may need replacing.
Or the fan may need reseating.

Also: which project is causing this?

I was running 60 and 70 percent of cores and cpu times and temps of system was in 80's. It started to get hot with fans roaring and found that there were various cores that flashed hot....even running at 20 per cent cores and 20 percent cpu....cpu temp bounces from 50 to 98 degrees.....any ideas

Yes, please begin with reading the posts in the below included thread, and then come back with the requested details:
When requesting help on these forums

I was running 60 and 70 percent of cores and cpu times and temps of system was in 80's. It started to get hot with fans roaring and found that there were various cores that flashed hot....even running at 20 per cent cores and 20 percent cpu....cpu temp bounces from 50 to 98 degrees.....any ideas

Look and see if there is a gap between the CPU heat spreader and the bottom of the heat sink. That actually happened to me and a copper shim fixit the problem until I found the correct cooler. I had the exact symptoms you mention.