Thanks for all the replys, Im glad everyone thinks I did a good job planing it out. The insulation is working out great, I put my 10*F frozen 135C excavator in a week back and in 8 hours it was up to 70*F, once the door was shut you would have never known there was 30,000 lbs of ice cold steel in there.
As for the wall on the inside they will soon be all covered with steel siding, I will get some pictures up soon.
The pit has worked out great, When I dug the hole for the frost walls I dug one big hole and the floor of the pit is only8-10 inches below the wall footings. The pit floor was poured at the same time as the footings and the the walls were all poured second, back filled and compacted then the 9-10 inch floor was poured over the top of the pit to lock it all together. In the floor of the pit I have a 5 gallon pail in the concrete for a sump pump. I want to be able to pump it out. That way if I ever have an oil spill it wont be getting in my ground water.
I have built a small bridge crane on wheels to remove the pit lids.