Wondering if it has enough mass to cool a 3220 Ivy Bridge. Will have airflow provided by a side mount 40mm fan.

Why go passively? The fan can run virtually inaudibly while keeping safe temperatures. Isn't there room for the slim fan?

Undervolt it and give it a shot. If there's another fan nearby it should be enough.

I've run it passive on a higher tdp i5 2400 with an 80mm case fan.

Gadzooks! There little chance of that being very quiet.

Let me elaborate lol, I am planning a build around the Wesena ITX2 case, which has 45mm of clearance between the motherboard and the ODD tray. If I remove the ODD tray, I can squeeze in another 25mm of space. The Big Shuriken, with its fan removed, is 46mm high. If I just used the case's side mount for the 40mm fan, would this provide enough airflow?

I did buy the newer Kozuti, but I'm worried about the sleeve bearings on the non-standard fan going (mounted horizontally). Will be nearly impossible to find a quality replacement.