I don't mean to seem argumentative, but thought i should note that if i heated for that long with any of my torches I would combust or be very close.
I know everyone and every torch is different, but i use my torches with the lowest flame i can without it sputtering and find that 4 seconds, a pause, and then 1-2 seconds is sufficient for a first (light) hit, and then repeating this a couple more times sees heat and clouds steadily increase.
Adding a second or 2 to the heating after the pause pushes the temp up.
@Whissmu technique might be perfect for you (hope i have not offended him-apologies in advance), but i strongly recommend starting with shorter heating times and edging your way up, because combustion smell is hard to remove from wood vapes, so avoid at all cost.
If you do combust, i have found that cleaning with ISO and/or acetone helps alot, but leaving the wood in the sun for a few hours (or even a day or two) is the best method to reduce that smell.
Good luck.