Imbert gasifier

How important is it to preheat the intake air on a small Imbert?

Hi Dale,
I have built a woodgas machine that runs a 4 cyl engine. I have been modifying for performance and cleaner gas. Success is helped by preheating the incoming air. I will have a video up soon of my new improved version of my gasifier. You can check it out the old one on You Tube. I have a channel "Gordon Ooghe" Check it out. Gordon