You nevered answered when queried about having outlet air out the cowl bottom, and only spoke of having the cylinder head open. Unless there is substancial outlet in the bottom of the cowl back at the firewall then you will likely never have a successful flight if there is no outlet at the bottom you have crated a stagnant bake oven. Now couple this with unrealistic prop loads as the fellows are mentioning then you will never have any success.

John