7000rpm on a 8mm 2-flute cutter too much?

Just been trying to carve a lump of 18mm thick ally for my Bridgeport conversion, using a 2-flute 8mm HssCo tool at 7000rpm, 900mm/min and 1.6mm DOC

All the features went without hitch, the perimeter decided to bog-down after getting about 9mm deep and stalled the axis.

I have a feeling the height of the wall blocked the coolant/air and allowed the tip to build-up. I need to fit two coolant jets i think at 90deg to each other.

I have re-cammed the profile starting from 8mm down and increased rpm to 8000 and reduced step-over a little.

Will see what happens tomorrow.