Alternative suggestion: Instead of messing with an engine oil pump and small hoses why not use one of these.
http://www.harborfreight.com/barrel-pump-45743.html
Remove the crank handle, replace it with a pully [or go direct drive], hook a small engine [lawn mower size would do nicely], Replace the pickup tube and exit tube with barb fittings [they are pipe thread openings] hook flex hose to them and pump a full 1 inch stream of WVO, WMO, or what ever you want.
At $30 for the pump, it's nearly throw away. But it's a vane type pump so it's self priming and Harbor always has them in stock.
I'm betting dollar for dollar you would be ahead to go this route.
I've tried trash pumps and had some problems getting them primed each time.