Fan Blade Question

I have been fighting a heating issue with my V6 JEEP since I rebuilt the engine. It runs @ 180*-185* running down the road in 100* weather. Once I slow down for in town driving it will kick up to 190*-200*, all depends how fast I’m moving. If I’m off road crawling trails it will climb to 205*-210*. I’ve added a pusher fan in front of the radiator and this helped keep temps down 5*-10*. I’m running a 3 core Champion radiator and the stock 5-blade fan and a Flow Kool water pump. I have ran a fan shroud off and on and it seems to run cooler without the shroud. I been down the rabbit hole and just purchased a 7-blade fan to try out.
Question:
How offset is your fan compared to radiator?

Mine is 5” below the bottom of the upper tank.

and about 3” below the top of the lower tank….. is this right?

 

I have about an inch between fan and radiator. I also have a 3-row core radiator with factory tanks. I tried an aftermarket 15" 6-blade fan, but it didn't work any better than the stock 15.5" 4 blade fan. I use a 180° thermostat. The fan is lower than the radiator but that's factory design.

This fan shroud helped mine immensely!
Fan Shroud for 225 V6, 1966-1971, Jeepster Commando, CJ-5, CJ-6 – The JeepsterMan

A close-fitting shroud is important.

I have an aftermarket electronic gauge, but I really don't think I have an issue. It does get warm on long pulls in low range.
FWIW, I recently tried a 16" Flex fan, but it would not work as the long blades interfered with the HEI vacuum advance.

 

What were the temps before you rebuilt the engine ?
Just looking for something in common.
Can you use a larger diameter fan ?

 

Sounds more like the thermostat is not opening fully.

 

How old is the flow cool pump ? Lots of problems with them have been reported lately .
Also a good fitting shroud helps tremendously. Check the thermostat that it is opening fully.

 

This describes mine exactly. I added a shroud (homemade) and a factory 5 blade fan and after that it stays at 180 even during 5 days of low range crawling in the hot desert.

 

How you feeling these days with your hip replacement?

 

This is the same shroud I have. I was going to try running it again with the 7-blade fan.

 

The temps were steady 180*-190* before the build. It is bored .60 over.
Complete rebuild.
http://www.earlycj5.com/xf_cj5/index.php?threads/118867/

I’m afraid to use a larger diameter fan because it already is below the radiator.

 

I’m pulling intake off to reseal so I’ll throw in a new thermostat. I’ll throw it in boiling water to see if it’s working also.

 

I was running a stock water pump for the last 4 years and switched over to the Flow Kool last year. It did help with the temps at lower speeds, but still bothering me that I need the electric fan to keep temps under control while at slower speeds.

 

Since I already have the 5-blade, I’m hoping that the 7- blade will make a difference. I’m also going to try running the shroud again.

 

Sent you a PM, didn't want to derail this thread.

 

The fan and shroud are clearly the most important items here. If you have a well fit shroud that doesn't allow air leaks between it and the radiator, your fan can be way off center and still work well. At that point it is sucking air through every part of the radiator. Most especially important at crawl speed. I don't much care for that factory shroud referenced above. With the open bottom, its efficiency is severely compromised.
This is the one I fabricated for the sbc in my 3B. It also covers the engine oil cooler located beneath the radiator.





However, as noted, if the thermostat isn't working, all efforts will be for naught.

 

"It runs@ 180*-185* running down the road in 100* weather. Once I slow down for in town driving it will kick up to 190*-200*, all depends how fast I’m moving. If I’m off road crawling trails it will climb to 205*-210*"

This is how my jeeps engine temp run. I also have a champion radiator and fan shroud with a 5 blade fan. I've tried several fan and radiator setups and the champion with shroud work the best for me. Even though i dont like when it hits 210° when offroading but its mostly when climbing steep obstacles for long periods. There doesn't seem to be any long term problems so far. I just keep an eye on the gauge to make sure it doesn't get hotter than 210°.

Im interested in how the 7 blade fan works. Where did you get it from? I couldn't find any factory or aftermarket 7 blade fans that would fit.

 

Don't put the thermostat directly into the boiling water, heat the thermostat and watch the temp at which it opens. You don't want to mess up a locking thermostat.

 

I was reading this thread and bought #J5357390. It will need the holes slotted about 1/8”.

http://www.earlycj5.com/xf_cj5/index.php?threads/156120/

 

Thank you.

 

John, I have always wondered how much that shroud is doing with the bottom open.
I went to the parts store today and picked up items needed to clean radiator and water passages in the block. Also picked up new thermostat and gaskets to check/change that out. New 7 blade should be here tomorrow. I plan on doing 1 thing at a time to see if I can figure out what the answer is.

 

Today was 81* out.
Ran down freeway Between 60-70 mph temp was at 190*


pulled off the freeway and stopped at bottom of off ramp and it immediately climbed to 195*