You can use a standard duty fan clutch vs HD/Severe Duty. Those usually don't roar, but they also don't cool as well as the HD/Severe Duty units. Efan issues = the shroud, the wiring, and finding an Efan which pulls 2800 CFM will be your battle.

Anyone can slap an Efan behind a radiator, but if you aren't using nearly all of the surface area to pull air thru the radiator = you are just making things worse. You will create hot spots and your temps will not be good. Also a lot of the Efans in the 2800 CFM and higher range sound awful all the time unlike a traditional Fan Clutch which only roars when it is engaged.

I did see a setup once which used 2 Efans on a decent bracket/plate/shroud, but the issue was then finding an Efan with enough CFM and I never did find any quality Efan's in the 2500 CFM or higher range.

 

I use the Hayden 2991 fan clutch like Walt recommended and yes, it sounds like I’m about to take off down the runway. But these engines NEED as much cooling power as they can possibly receive.

 

Has anyone tried the Hayden 2781?

 

Well, it’s not the fans, as I have check All of them and they are all working at full.

I either still have an air blockage in the system or gunk creating a blockage.

I posted a new thread on it today as it does some weird things with the e-brake on and off on the cluster gauge.

 

blockage can be a real issue.