Quote: To find optimum hole diameter for a shroud take the fan diameter and add 10% of the fan diameter. So for my 16" fan I added 1.6" to 16" and cut my hole at 17.6".
The optimum depth of the shroud is when the pitch of the fan blades are showing 1/2 in and 1/2 out of the shroud.
That info came from a past employee of a large automobile and industrial radiator manufacture explained to me the design of a fan shroud.
Is a 17.6 hole big enough to not allow the fan to hit it when the engine mounts flex?
