Here are my recomondations for casting lost foam in greensand
. & i got a lot of this from FranKG btw.
#1- since your molding sand will hold shape, you have the abbility to use standard gating, traps & blind risers to controll solidification....
dont wast a bunch of time with intricate gates & risers in foam. (a mistake i made early on in my learning) they just steal heat from the pour & slow down the fill. Just lightly ram your part in the cope & cut normal runners & gates in the drag.
This works really well with simple patterns with a clean parting line like your pulley. more intricate shapes & really odd stuff you'll have to use some imagination.
I have never understood the foam vents i see guys putting on patterns. a foam rod (or drinking straw) is effectivly a "plug" & has to burn out before metal (or the intended gasses) can flow into it...& once metal is there it is not functioning as a vent
Simply running a wire into the sand to make the vents is far more effective & will actually vent gas traveling through the sand....Use a pc of .5mm wire & poke 100 holes into the top side of the cope to the pattern. Too large a wire will make a porcupine surface on the cast part.
whip up a bunch of simple rings & do a few test pours to develop your style & build confidence.
For 99% of my casting I use propane & a modified reil burner with a blower assist. I have an oil burning set up, but its a hassle & a mess to set up & tear down. the propane is easy,clean & fast. (worth the extra expense for me)
now, less foundry & more bike please