Fan Shroud Modification for Fan Depth?

[Jeff10]

Hey,

A couple of the old school wheelers on a trail run here in Moab suggested that I should cut my Ron Davis fan shroud to improve the efficiency of the fan/radiator.

According to two of these folks, the fan is too far inside the fan shroud. They said that the back side of the fan needs to be outside the shroud to operate correctly. (One of the guys said that without that gap, the shroud causes the air to cavitate around the fan blade, disrupting the air flow.)

I hate to cut up that expensive shroud. If it will make for more efficient cooling, though, I will do it.

Any thoughts?

Thanks

Jeff

 

[bronconut73]

Hey,

A couple of the old school wheelers on a trail run here in Moab suggested that I should cut my Ron Davis fan shroud to improve the efficiency of the fan/radiator.

According to two of these folks, the fan is too far inside the fan shroud. They said that the back side of the fan needs to be outside the shroud to operate correctly. (One of the guys said that without that gap, the shroud causes the air to cavitate around the fan blade, disrupting the air flow.)

I hate to cut up that expensive shroud. If it will make for more efficient cooling, though, I will do it.

Any thoughts?

Thanks

Jeff

Yup they are quite right.
Can you use a thinner fan spacer to pull the fan back out of the shroud?
If you do trim that shroud be sure to make it look good because those Ron Davis shrouds are beautiful. Maybe you could have a machine shop do it so it will look original. Good luck and keep us posted.

 

[BRONCOBERT]

Ron Davis has two types of shrouds the full circle and a lesser expensive one that is more like the original OEM, I assume you have the full circle. Could the lesser expensive one be the better choice due to the disruption of air flow with the full circle?

 

[bronconut73]

Hey,

A couple of the old school wheelers on a trail run here in Moab suggested that I should cut my Ron Davis fan shroud to improve the efficiency of the fan/radiator.

According to two of these folks, the fan is too far inside the fan shroud. They said that the back side of the fan needs to be outside the shroud to operate correctly. (One of the guys said that without that gap, the shroud causes the air to cavitate around the fan blade, disrupting the air flow.)

I hate to cut up that expensive shroud. If it will make for more efficient cooling, though, I will do it.

Any thoughts?

Thanks

Jeff

Yup they are quite right.
Can you use a thinner fan spacer to pull the fan back out of the shroud?
If you do trim that shroud be sure to make it look good because those Ron Davis shrouds are beautiful. Maybe you could have a machine shop do it so it will look original. Good luck and keep us posted.

 

[Broncobowsher]

And the old folks are right. The fan should be 1/3 to 1/2 into the shroud (I accept full depth at the top for a finger gaurd feature). Another reason for it is the fan is also part radial flow instead of purely axile flow. Especially true since the fan sits so close to the engine block. Pulling air through the radiator is half the job, it has to push it somewhere. So a little centrifical action helps move more air. The fan not so deep in the shroud helps this.

I was helping a frined with electric fans mounted on a very nice homemeade shroud. by simpley moving the mounting points from inside the shroud to outside the shroud, moving the fans back only ¼" made a noticable difference in how strong the fans would pull a shop rag to the grill.

 

[ScanmanSteven]

I have my explorer serpentine fan buried in the shroud and it's like a wind tunnel. So for it has it has cooled okay. My wife's 01 Liberty has the fan recessed also so when I fabbed mine I did the same. I've always heard 1/2 out but....

 

[spap]

I guess the main question Is your bronco overheating or running warmer than you want. If it isn't why waste the time.

 

[crankman]

Jeff if your not having cooling issues i would leave it be. I mean heck if your application is cooling your rig why go modifying.

 

[Jeff10]

Hey Guys,

Thanks for all the advice.

I solved any overheating problem on Saturday when I managed (I think) to break the capillary tube for the temperature gauge. Thanks to my new BFFs at the O'Reilly's in Moab I now have a new temperature gauge (and capillary tube). I'll install it this afternoon and then keep an eye on it tomorrow. (One of the gunners on the Labor Day Safari loves wheeling so much that he is going to share his knowledge tomorrow and Friday. We're stoked.)

I don't believe I have a cooling problem as the radiator stays full and the overflow bottle stays about where it is supposed to consistently. I'll post up temps tomorrow.

I like the shop towel trick. (We do the same thing with booth balance activities.) I really hate to cut it. I also hate to think about removing it to add a thinner spacer... but, I will do it if there's a problem.

Thanks again for all the input.

Jeff