modify yourmechanical fan shroud?

modify your mechanical fan shroud?

Has anybody ever modified their mechanical fan shroud to help it suck more air thru the radiator by having it wrap around the fan a little further?
What I mean is on the top of the fan, the shroud covers most of the fan blades for protection of anyone sticking their head under the hood when the engine is running I would assume, but once the shroud goes below the height of the rad that big shroud is cut way back and only extends about an inch from the main shroud body, so I was thinking about adding a little plastic or sheet metal to the sides and lower part of the shroud to allow more suction from the fan thru the rad. What do you think?:anon:

sounds like a good idea, im just going to buy another electric and replace my mech fan.

jeepdude10000 said:

sounds like a good idea, im just going to buy another electric and replace my mech fan.

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i was thinking about doing the same but im not sure what fan is the one to get

I too have contemplated replacing the mechanical fan with an electric but the extra electric I have is from a 98 dodge caravan but is too deep (4") and I'm to cheap to go buy a high dollar thin electric, especially when I may be able to improve what I already have in the mechanical fan.

I bought a Hayden to replace my secondary one since it died, it works great but it does not have much shroud, mind u its only 3" thick - works great though.

jeepdude10000 said:

sounds like a good idea, im just going to buy another electric and replace my mech fan.

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Funny.. I just did the opposite. Had dual electrics (installed by the previous owner) that worked fine in the winter and spring, but as soon as summer hit, they failed to pull enough air to cool the engine. If you do decide to go all electric, be sure that you get fans that pull 2000+ CFM and are slim enough to clear all moving engine parts (pulleys) enough to ensure no contact during all possible movement of the engine (I dropped the front wheels off of a rock and the engine flexed forward enough to make one of the electrics eat itself).
I looked into buying new electrics as well as pulling an Taurus fan from the PnP. New electrics of sufficient power were going to cost far more than new replacement parts for the OEM system and the junk yard parts were going to take more effort to install than I wanted to commit. The knowledge that I have a fan that will work as long as the engine runs is very comforting to me.

Most that convert to electrics generally convert back once it warms up. I trimmed my mech fan shroud, well, actually broke it, broke the bottom off so now my shroud is U shaped but still has the two tabs so it locks in on the bottom, bought a new one but so far I have had no problems so I have not replaced it... but I'm ready just in case..

So, if nobody has modified their Mech. fan shroud to extend it some around the fan more, do you think it won't help pull more air thru?

The closer you can get a shroud/duct to the ends of the blades the more efficient it will be (induced drag and all that). The problem is estimating how much the fan moves wrt the duct to avoid contact. This might me easier to solve by adding a shroud on the blades and then running the duct right up to it so contact will not necessarily result in busted blades but just shroud/duct rubbing. Then the issue would be whether the increase in efficiency is significant enough to notice.

I'm beginning to think a change to the plastic "grill" might result in better airflow.

I actually cut my mechanical fan shroud at the bottom. I was having cooling problems and was having to take the shroud off every time I tried something new. After replacing the radiator to a 3 core, the shroud wouldn't slip through anymore so I notched the bottom about an inch deep and 4 inches wide. It didn't make any difference in the cooling (didn't run warmer) so I don't think extending the shroud would make it run cooler.

The one thing I did that solved all my cooling problems just happened to be the cheapest too. I changed my fan clutch.

The new rad, the thermostat, the ext. tranny cooler didn't change anything, but the fan clutch has me running 190 all the time... even with the AC on wheeling in 94 degree weather.