fan/radiator clearance

[krue0101]

Hello,

I am trying to determine the optimum clearance between the fan and radiator on a gasoline engine.

I am talking about a pusher fan that is pushing air through a liquid radiator on a home made tractor.

It seems like I have found somewhere that the fan should be placed as close to the radiator as possible, but I can not find any fluid flow reasons to back this up.

I am really interested in the theory behind this topic. Can anyone give me a hint?

Thanks

Joe

 

[patprimmer]

If an effective shroud is used, the distance is not important, however, however, if the fan has no shroud, the further the fan is from the radiator, the more room there is for air to divert and bypass the radiator.

Regards

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[MikeHalloran]

Absent a shroud, minimum clearance is probably more critical for a puller fan than for a pusher fan.



Mike Halloran
Pembroke Pines, FL, USA

 

[EngJW]

Would your minimum clearance more likely be determined by mechanical considerations- movement of the engine in is mounts, movement of the radiator, variations in fan location, variations in thickness of the radiator, etc. I don't know if it can suck up any debris (or a cat sleeping under the hood, he he), but if so you would want it to pass through.

 

[krue0101]

Thank you for sharing your expertise, it is much appreciated.

Joe K.