The motor compression is separate from the oil pump feed, they can't interface with each other.
I'm with mt.aero, I don't think you can pump enough oil through the pump to move that much in 10 miles.
But things to check:
1 - You have the lines to the right ports hooked up. The different ports on the oil pump feed different amounts of oil, crank bearings get less than cylinders and such. Make sure you have them hooked up to the right locations.
2 - Check each of the oil ports for their check valves working. The little fitting that the line plugs on to (not the oil pump end the other) is actually a check valve. It doesn't take a lot of pressure to push through it, but it does take a little bit. I use a small syringe and push oil down the lines. When you first start to push there will be resistance and then you'll feel the check valve open and let the oil in.
3 - Make sure you aren't pressurizing the oil reservoir some how. I don't know how that could happen, I've seen them vacuum lock, but not pressurize. Check that your cap is venting.
sled_guy