fan shroud dilema

[meeyah]

1071930

I have a CJ7 with a V8 and my jeep keeps running so hot I thought a shroud would help. The shroud fits fine on the radiator but the fan is situated lower and off center so the blades are hitting a good portion of the bottom of the shroud. I cant lower the shroud because it would be hitting the bottom hose coming out of the radiator. Can I cut out the section that is in the way, the part that the fan is hitting or lower the shroud and cut out a little section to fit over the lower hose? Someone else suggested that I cut the blades of the fan, but won't that make it harder for the fan to do it's job?
I appreciate any advice!! :-? [addsig]

 

[84_CJ7]

1071932

I always thought that the shroud was more for my protection than for the engine's cooling :roll: I would think that if it is getting that hot you may have other issues such as thermostat, waterpump, heater core, coolant or radiator. Has everything else checked out okay? If you are getting it that hot you need to give it every advantage to cool down, The shroud may help but I don't believe that it will solve your problem. DON'T cut the blades. It will hurt your cooling and if not done exact will add strain to your water pump by wobbling. Why are the hoses in the way of your shroud? Not factory?

Scott[addsig]

 

[Greywolf]

1071946

Only things I can suggest are: if you use the shroud make sure that it's the right one for your application (or as close as possible)... ie: the V-8.

I ran into a similar problem some years ago when I had a high performance engine put into my Chevy pick-up. The factory shroud didn't give it enough air to breath. I took the advice of a master mechanic and ended up using one from an early 70's Chevy station wagon (fully loaded, all options) of all things. It was deeper (putting more shroud around the fan), allowing more air to circulate behind it, rather than dissipating as quickly as it would have with the shallower, factory shroud. Never had another problem.

One other thing you might look in to... do you have a "clutch" fan? If so, the spring (clutch) on the fan might be bad or going bad. This would keep the fan from working the way it should thus robbing you of much needed cooling ability too.

Good luck,

Chris[addsig]

 

[MORGSTER]

1071950

The fan and shroud work together to create a (for lack of better words) airflow tunnel and cutting the blades or the shroud would interfere with that process. (Thus reducing your cooling) (Actually, cutting fan the blades might cause more problems with balance, at minimum, wear out your water pump much faster) I went to an electric fan set up that has been great on and off-road. This would solve your alignment problem, keep the air flow, and reduce the power robbing clutch fan thus adding power.

Here is a previous post and update with fan information:

If you go to search (Electric fans) you will find very long discussions about this subject.
Here is an excerpt from my post after installation.


PAST POST:
After all of the information provided by my fellow Jeepers I installed the Flex-a-Lite #150 Black Magic fan. (1989 YJ 4.2) The extra airflow and heavier duty motor over the #475 looked like the ticket. I also called Flex-a-Lite and picked up the nice aluminum mounting brackets that usually come with the #475 Wrangler 2 which made the install secure and sanitary. The only problem with the #150 is the extra ½ inch depth over the #475 Wrangler 2 that was caused by the larger fan motor. A little customizing was needed where the radiator mounts to the body, which gained ¾ inch forward movement of the radiator, giving me the clearance I need. I installed a 160-degree motor thermostat in addition to the adjustable fan thermostat; rock crawl cooling no longer is a problem. The nice part is one simple turn of the adjustment knob and I can select the temperature I want. This weekend the desert rock crawl testing with air temperature up to 100 degrees went off with out a hitch and I’m happy. There was also a noticeable increase in throttle response and hill climbing power on road.

UPDATE:
Four or so months later and now it the start of the summer heat waves.
The Flex-a-Lite #150 has been installed for several months of street and off road driving. The outside air temperatures have climbed and it's summer testing time. So far the installation of the electric fan has been worth the effort. Power increase has been tested well (I live on a very long/steep hill that, because of gearing, creates the need to run in second gear/max speed (Automatic trans) while climbing to the top. The removal of the clutch fan and installation of the electric fan added an additional 9mph on that climb) During off road, freeway traffic and highway motoring, temperatures run at a cool 165 degrees without fluctuation. (160 is where I have the automatic fan start) I have reset the unit to run with the key switch because the noise at 2am (Coming home late) of the fan running after shut off is annoying. The addition of a under dash on/ off switch for river crossings works, but has not been needed. (The fan unit is designed for water abuse although my concern was the wire terminal block on the fan shroud shorting out)

All in all, this upgrade for me rates an A+. [addsig]

 

[firemanharry]

1072028

DON'T CUT THE FAN!!!!!! Trim the shroud however you want to make it work. If that doesn't work then you'll have to look someplace else for the cause. [addsig]

 

[meeyah]

1072030

Why are the electric fans better?
I am not sure that it will fit in between the radiator and the transmission cooler. How much room do you need for the flex 150?
Thanks for the great info!
Maria[addsig]

 

[Snitty]

1072062

if you have a transmission cooler, i'm not sure where it is located, not sure on how the fan will fit... but with a manual transmission... the fan fits great... and it is better for these reasons:
- operator controllable, you can turn it off and on for water crossings, or to let it warm up in the winter
- better cooling at idle
- you can have it run when the engine is off
- eliminates all fan drag on motor
- confuses mechanics[addsig]

 

[firemanharry]

1072063

I like the last reason. :lol: [addsig]

 

[MudderChuck]

1072068

Could be a number of things, but one thing, to look at, on the Chevy motor. Is the thermostat housing. There are two different types and a number of comfigurations.
Early Chevs, had the heater, being feed by hot water, at all times and only the vent doors opening and closing would control the heater. The heater acted as a bypass and kept the thermostat supplied with actual engine temp. water, not just what happened, to be right next to the thermostat. Later models had a small bypass built into the thermostat housing.
Over the years, I have seen a whole lot of guys, change there intake or build a race machine, that overheated, because the thermostat had no bypass.
Another thing, that caused problems, was the spring in the bottom radiator hose. The water pump is strong enough, to suck it flat at higher RPM´s.
I prefer electric fans, also. When I install one, I tend to overkill. The biggest most powerful I can find, to fit. I´ve found a number of winners, at the junk yard. OEM, mostly on Jap or European cars (or trucks).[addsig]