Cooling Fan Question

[handcannon]

On a Toyota forum I've been passing information along to a guy who is swapping a 1994 F vin 6.5 TD into his FJ60 Landcruiser wagon. He is currently looking at different ideas for cooling the 6.5. One of his ideas is to use the 6.5 radiator in the FJ60 core support. But, this would be without increasing the size of the stock FJ60 radiator opening to allow full air coverage to the 6.5 radiator.

Another idea he has is to get a three core aluminum radiator that is designed to fit the FJ60 core support, and cools with dual electric fans. The radiator supposedly will support up to 550 HP. According to his memory the fans move 2300 CFM each, or a total of 4600 CFM.

It seems to me that somewhere I read what the stock 6.5 fan CFM was, but I have searched and so far been unable to find any CFM number.

I'd like to help this guy, but don't want to steer him the wrong way. I have concerns that the electric fans won't move enough CFM. But, I also have concerns about using the stock 6.5 radiator in a situation where the radiator core is partially covered by the FJ60 core support. Can anybody please help me with a CFM number?

Don

 

[ak diesel driver]

10,000 is what I've read on here. never seen any numbers anywhere else

 

[dixiepc]

I have a Suburban and I don't even use a fan most of the year.

 

[WarWagon]

10,000 is what I've read on here. never seen any numbers anywhere else

This number is what I tried from a measured Trailblazer SS EV clutch fan in place and hood closed on a Trailblazer SS. That fan at 10,000 CFM does not have enough pitch for a 6.5 while towing thus doesn't move enough air. I tried and was heating up with the AC on pulling a decent grade. The 19" steel fan and Duramax fans move a lot more air in the 6.5's RPM range. We also have thicker radiators than the Trailblazer SS and this would affect the CFM number if I measured it on one of our trucks.

Is he using AC? What part of the country or what is the summer temps? Planned use: DD or off road rock crawler?

I would suggest using the biggest radiator that fits. Factory footprint and a thicker radiator. Gas HP radiator ratings are worthless for a precup in head diesel that has 2" radiator hoses vs. 1.25" gas engine hoses... Airflow in CFM and radiator thickness make a difference as separate variables. Lots of CFM with a thin radiator won't cool you off like found in a Stock Trailblazer SS. In our case (6.5's) we don't have enough CFM but plenty of radiator thickness.

Going off road through deep water electrics can be turned off. I would look for some 2005+ 1500 Chevy fans or Ford Taurus/ Lincoln full size car electrics. Electrics I wouldn't mess with unless you have to. CFM just isn't high enough and electrical issues/problems including needing a big alternator always come up. Good fans draw nearly the same juice as the glow plugs.

My preference is to use the 19" steel clutch fan and build a shroud for it as well as single t-stat HO water pump. 21" only if it will fit.

To reduce the heat kept in the engine exhaust work is needed including a better turbo than GM gives us. The turbo makes a big difference in cooling needs.

 

[SS FORCE]

I have been running dual electrics on my rig. Flex-a-lite. They pull 5000 CFM combined. I have no problems running the ac or driving around town or highway. Its gotten hot climbing really steep grades going slow (5,000 to 10,000 ft in 5 miles) and towing up canyons. Other than that I love the freed up power with the clutch fan off. Since I switched turbos it has only helped the truck run colder and I see even less cooling issues.