Advice on reducing heat in engine compartment (1 Viewer)

[workingdog]

I hesitate to post this, as I'm sure I'm going to get a lot of abuse. But, I'll risk that knowing there's a lot of wisdom her.

My rig runs great 99% of the time, the only time we have trouble is when we are wheeling slowly for a long period of time when the engine and the transmission both overheat. I'm looking for ways to manage the heat. Most recently, we spent hours coming up Foredyce when both engine transmission were overheating and the fusible link finally blew - leaving us dead on the trail, coolant boiling in the expansion tank, transmission at 220.

Here's the summary
'84 FJ60
2005 5.3l vortec (CA smog legal)
Magnusun supercharger
Mechanical fan
4L60
Atlas xfer case
Exhaust running back close to transmission, essentially wrapping around transmission

I'm assuming that the supercharger and exhaust are creating a lot of heat under the hood that the mechanical fan can't dissipate at low speeds for long periods of time.

So, here are the options I'm aware that I'd love hear opinions about - and other options would be appreciated.
1. Remove the supercharger and replace with stock intake. I love the power, but I could live without it.
2. Ceramic coating or wrap on headers and exhaust all the way back to the CATs
3. Convert to electric fan so that air is moving at low speed
4. Massive vents in hood to allow heat to escape at low speed.

Peter

 

[CruiserIRL]

I can offer some help regarding transmission heat. You could ceramic coat the exhaust, like you mentioned. As well as, add a transmission cooler to add fluid capacity and keep it cool. But, as far as your engine bay temps, look at a newer/more efficient radiator. Do you still have the fan shroud installed? Without a shroud or larger enough radiator, crawling on a trail without much air flow could be the issue there.

 

[workingdog]

So, I should have given more details. We have two large transmissions coolers in front of the radiator. We were overheating the transmission in everyday driving, but these new coolers fixed all that. And the radiator is a brand new aluminum Rod Davis. And it has a fan shroud.

 

[tclark]

I say ditch the supercharger. I don't know that you can stay with a stock size radiator, even a hi-perf one, and keep a setup like that cool reliably. You need to figure out how to mount a larger(ie wider/taller) radiator and get good airflow through it.

That said, hood louvers may help some.

 

[Mace]

If you are fine while driving but not while idling it's an airflow issue.

I would start looking at a pusher electrical fan to help or see if your mechanical fan is operating properly.

 

[OSS]

As Mace said. The radiator fan isn't pulling enough air at low RPMs.

 

[workingdog]

Yes, I agree, so what's to be done? I'll post pictures of fan and shroud to see if there should be any changes made.

 

[tclark]

Why was the trans overheating in normal driving?
Are you running stock sized radiator?

 

[workingdog]

Before we installed the additional trans coolers, the cooling provided by the coolers originally installed was not enough and the transmission was overheating fairly quickly. Yes, radiator is stock size Ron Davis. I have assumed that having exhausted routed on both sides of the transmission was contributing to it overheating - on of the CATs ended up very near the transmission.

 

[workingdog]

Here are shots of the fan, shroud and transcooler.

 

[RredFJ40]

Won’t address the trans, but how are your heater supply and return lines routed from the water pump? Could you post a pic of them? They have to be tied together so that coolant can return to the pump even if the heater valve is closed.

 

[MANUCHAO]

So, here are the options I'm aware that I'd love hear opinions about - and other options would be appreciated.
1. Remove the supercharger and replace with stock intake. I love the power, but I could live without it.
2. Ceramic coating or wrap on headers and exhaust all the way back to the CATs
3. Convert to electric fan so that air is moving at low speed
4. Massive vents in hood to allow heat to escape at low speed.

My $0.02
Removing the super charger would probably def make a huge difference....
I remember reading some time ago 80 series guys running superchargers face the same dilemma...

Coating the headers would def help....
Isolating the fusible link with some thermal barrier (fire proof) of some sort ? Just taking a guess here.....

If you have the space (and the will) to push that radiator back and move the tranny coolers and the AC condenser into the engine bay and install a pusher electric fan on the front....(I know...that sounds like a lot of work...)

Last but not least... I gots a hood with vents sitting in my shed.... you are welcome to it....as I dont need it or see putting it back on my rig.....
Reason I took it off: It really made a mess of my engine dust and then rain.......
It did drop the temps on the engine bay a few degrees, but I agree with others.... check your current system for air flow... I know my mech fan locks up at certain temps in low moving conditions and keeps temps down......

 

[workingdog]

Heater hose pics

 

[LCnAZ]

Yes, I agree, so what's to be done? I'll post pictures of fan and shroud to see if there should be any changes made.

Your fan clutch is okay, right?

I'm fortunate to not have tranny temp issues, but the engine compartment heat is amazing. Of course, we don't have condenser fans like modern vehicles. I've overcome the latter in hopes of also helping the former. See D.I.Y Pusher Fan on 60

I have just completed adding the fan on my '90 62. That is an OEM-style radiator, so I don't have an exterior tranny cooler. This is the largest after market fan I have seen installed in a LC with the OEM-style radiator with that darned line running in front of the condenser. You can read how I worked that out.

I have mine rigged with a temp probe through the radiator fins, rigged to the battery bus, and with a kill switch in the vehicle. On at 180F, off at 165F. My hope is that this will help during driving as well as cool down of the engine compartment after shutdown. I will begin driving and evaluating over the coming weekend.

Here is the controller. https://www.amazon.com/gp/product/B01E52NG5O/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

I'll try to provide some meaningful feedback on its effectiveness.

Another thing I may look at is changing the carb vent motor to a different t-stat that will allow it to work better. In fact, I know that above controller will run two fans. I just don't know how much load the carb fan pulls.

 

[RredFJ40]

Heater hose pics

View attachment 1768749

View attachment 1768750

View attachment 1768751

I’m not seeing a way for the coolant to return to the water pump when the heater valve is closed. This creates a dead end. Chevy systems are set up to constantly flow through those heater lines, different than the Toyota design. Just to test it out, bypass your heater core and tie your supply and return together to loop that coolant back in the water pump and see if your cooling capacity improves.

 

[RredFJ40]

Your fan clutch is okay, right?
.

And this. Make sure the fan clutch is up to snuff.

 

[lcwizard]

So, I should have given more details. We have two large transmissions coolers in front of the radiator. We were overheating the transmission in everyday driving, but these new coolers fixed all that. And the radiator is a brand new aluminum Rod Davis. And it has a fan shroud.

The tranny bothers me. @0 some years ago when I did my first swap with the 700R, I used a recommended builder. Supposedly one of the best.
That tranny ran between 220 and 240 nearly all the time with two coolers. The next three he built did the same. I changed to a builder in north Phx, Ken's Transmissions, basically because he was much cheaper. He has done at least two dozen 700s, 4L60s, a C-6 and the one in my Dodge dually. None of his trannies ever ran warm. Mostly the opposite.When I pulled the 700r from my FJ55 with 35" Swampers it had always run over 220. I swapped to the Ken's 700 and it consistently ran 175 plus or minus 5 degrees. I don't build autos so I can't give you the science but I still use Ken's, 20 years later, even though it's over a 100 mile drive.

 

[cruisermatt]

Yeah, those heater lines are an issue. Put an “H” in them as a first step and see what that does. Excess heat in your engine bay also means excess heat on the transmission coolers.. you might see a slight drop there too.

And the mechanical fan not sufficient? Impossible! This is Ih8mud where mechanical fans are the end-all cooling system method for some reason.

And removing the supercharger? Are you serious dude? Maybe you should just put a 2F a back in it..
Actually, send that supercharger my way, I’ll even pay shipping!

 

[Feistl]

As above you need to sort the heater hose.

Secondly, a pair of electric thermofans instead of the mechanical one will help however it has to be setup properly. Measure the radiator core size then head to a wreckers and find something with twin thermofans that will cover that area. You need to seal the shroud as much as possible...

Also look at getting a pwm controller (say 40amps) and wire the thermofans up to always be running at a slow speed (adjust the speed with the pwm controller so it's as fast as possible without being able to hear it during normal driving).

The other question is how good are you with a welder? I fabricated up a new radiator mounting system so I can run a much larger radiator (from a gtr skyline actually). I can post some pics if you're interested.

Cheers

 

[workingdog]

Yes, I'd like to see the pics - what is a GTR skyline?

I'll work on the heater.

And, I am aware that mechanical fans are sacred here. But ....