intercooler affect on radiator load (1 Viewer)

[gerg]

I noticed a dramtic decrease in the temps (3b) after my top mount intercooler install, but still struggled with temps towing my trailer (5000lbs) up similar grades like yours in summer. I had a 3 core brass full mechanical fan runing egts around 1200f max. I would look into making sure all of the foam sealing around the rad is in place to prevent it from sucking hot engine air rather than cool outside air. It is common for the foam to disintigrate. Make sure your fan shroud is not leaking that way as well. I was going to go to a mini truck fan but it would need a bit of work to clear the rad hoses as it runs closer to the block than the stock fan. Maybe an 80 series fan would fit better. I never tried it though. Before you add an extra radiator I would look into a oil cooler. I would only do a second rad as a weird last resort. Upping your boost to net lower egts will help with rad temps as you will shed less heat into the exhaust runner. I would think an intercooler would be better though. Remember that front mount intercoolers, although they are great at cooling the charge air, shed that heat directly in front of your rad, making your rad less effeceint just like your ac does. I use to get the very real sence my engine was super heat soaking before my top mount intercooler. My egts after long hauls would climb effortlessly it seemed. After poping my hood I was scared to touch anything int the engine bay it was so hot. Engine ran much cooler later, although I was still pushing it hard and the temps would slowly climb.

Here are a few suggestions I would do in your shoes in order of ease and cheapness fomr a guy who has blattled heat for a long time.

Full mechanical fan (weld.. wire.. zap strap what ever way)

Increase boost a couple lbs with no extra fuel, or decrease fuel a tad (prefered)

check thermostat that it fully opens (boil in a pot of water)

Wrap headers and turbo exhaust housing.

Reroute air box to only draw cold air and no engine bay air

hood louvers

New water pump

Fit a larger fan (either a mini truck or you could try a 80 sereis as they are larger too)

oil cooler

Intercooler

Dont underestimate the effect of louvers and ducting and stuff. I tried an experiment with my 80 as Im getting ready for a vacation drive to Oregon with my trailer. The 1fzfe has a nasty habbit of melting engine harness wires. So last week I took off the rock guard from under the rad, hoping to help the rad breath easier, as well as proped up the hood with a few washers to act as a cowl to draw in cold air off of the windshield cooling exactly where the wires seem to usually melt... well that actually had the net effect of drawing in cold air yes, but it inhibited the rad from drawing in as much air as well. The trucks temp slowly started to climb to where it would have overheated just driving down the freeway unloaded where as I towed my trailer fine the week before with no temp issues at all with everything in place stock.

Do some reading on cooling issues, most dont arise from too small of a rad. Its usually a combination of other things. Keep in mind what Dougal said too. IDI engines shed alot of heat naturally. I hate to say it, but in my opinion your engine probably sheds the most heat per Hp of any engine Toyota mada. I am sure though there is a solution out there for you. Try the simple things first before you make big changes.

g

 

[o8ko8k]

thanks for the suggestions, this is encurraging that there are other alternatives to adding a butt load of radiators to my vehicle =D

For reference here are a list if the things ive already done:

1.heat sheilding the turbo and exhaust pipe in engine bay
2.new Fan clutch
3.SHroud inspection
4.radiator/shroud/radiator/ac gap sealing
5.not running the AC on the hill climbs
6.Running both heater cores full blast with the AC OFF on the hill climb
7.Rad flush
8.Water wetter (coolant cavitation preventative)
9. New radiator (and to satisfy the judging types, the radiator i had b4 was leaking and needed replacing anyways so relax im not crazy people).
10. new hoses


what i have yet to do:
1. thermostat
2. water pump
3. locked fan clutch


here is a list of things i find noteworthy:

1.The FJ60 fan clutch vs HJ60 clutch activation temps are both irrelevent at 210F so if fan clutch is my issue, my 2h has destroyied the new clutch with is awesome torque.

2.The heat imposed into the cooling system from an intercooler is NOTHING THE SAME as the heat introducted by the AC. The net effect of an intercooler is LESS HEAT into the system and even less heat out, because the source of that energy is the ambient air and you wont pass 100% of that back into the water radiator so the net effect is still less input engergy and the greater engine efficiency means even less energy output.

The net effect of the AC however, is MORE HEAT into the system because the source of that heat is coming from additional engine load and the cabbin. Essentially you are pumping heat out of the cabbin and into the engine AND that isnt 100% efficient so the work done to acomplish this is done by the engine as well. super nasty activity in terms of trying to keep your radiator under control.

I apreciate the feed back b/c it helped me model this concept in a way i could understand. Internal combustion theory is based on heat engine theory; Heat in -> work -> heat out. Ratio of in to out equals efficiency. Hot air in means lower efficiency thus total heat out increases. when the air is cooled then the efficiency goes up more work is done per unit heat, less heat comes out. this is percieved by the driver as more power but its coming from efficiency AND as many have mentioned the human desire to put your foot in it more.


3. IIRC the 2h has a pretty substantial oil cooler that runs the legnth of the block... So, I would think that the oil temps would be pretty close to the water temps. in which case,why put another oil cooler on when its already got one? (and if anyone is thinking that the hot water on hot oil is silly, IT ISNT! Adding an external oil cooler is absolutly no different than adding a second water radiator so this suggestion appears recursive to me).

4. greg, so many questions, so little time, can your rig run a hill like i described and keep the the coolant temp at 180F? I could use some examples as a point of reference, as 5000lbs of trailer behind a 2h engine sparks my interest and further encurrages me that there there are alternative solutions i need to consider. what boost to do you run and how much fueling (egts when pulling the hill). Did you upgrade your pistons? (how far did you juice up grampa?)

ANd to be clear, i absolutly intend to fool with the thermostat and water pump first. But i do like to explore out in front of my next move. So rest asured i wont do anything crazy. ok i take that back, ive done a lot crazy... i think you kinda have to be to own one of these things...

and in case i didnt say it, yes stacked radiators are not going to perform as well as ones that arent and heat soaking is a real bummer. But there is only so much room for things and compromises must be made.

 

[o8ko8k]

After installing the turbo, you should adjust your timing. The Toyotalift shop over on 26th Ave might be able to do it if you want a place that knows something about the 2H, otherwise any good diesel shop could probably handle it.

Is it I-17 up to Sunset Point, or is there another one?

Thanks for the recomendation, ill look them up. Ya i have been reasearching a good diesel shop that could asist me with stuff like that

up to Sunset point, the hill over to camp verde and back, the hill up into flag, the hill into payson, the hill from pason to strawberry, practically everywhere that gets me somewhere cool where i would want to camp!

anywhere there is a yellow triangle on this map!
http://www.mountaindirectory.com/sample/arizona-map.html

 

[Dougal]

Get your radiator rodded out. A flush can only do so much, but with a tank removed and the cores physically pushed clean you'll know it's good.

Turbo 2H's are known for being marginal for cooling. But you can be on the cool side of the margin if everything is good.

 

[o8ko8k]

Get your radiator rodded out. A flush can only do so much, but with a tank removed and the cores physically pushed clean you'll know it's good.

Turbo 2H's are known for being marginal for cooling. But you can be on the cool side of the margin if everything is good.

the radiator is new but when i rebuild the engine, i will be rodding out the block and water/oil cooler as best i can...

 

[o8ko8k]

nobody take this the wrong way but if this engine is known for having heat issues, what exactly makes it so crazy to put a larger radiator volume into the equation?

I certainly apreciate all the suggestions as they are all very good ones and im asking for this kind of info and i collected a few things that i missed. Thats what the forum is all about too, others can read this and see the big list there in all its glory.

But PLEASE can someone/anyone take a look at the proposed analysis I did that concluded the stock one is too small and see if the results hold water or needs refinement? I think there is a fantastic argument in this thread that the stock radiator is not big enough for a turbo.

Thanks!

 

[TheBigBoy]

It will need a larger cross sectional area, not a thicker core. So that isnt really going to help much, as the cross section is already as big as it can be. The BEST thing you can do for turbo 1HZ is a really good intercooler. And then dont wind the fuel back in as much. If "hypothetacally" it was running 20:1 before, and now intercooled is running 27:1. Wind it down to 23:1. Sure winding it down to 20:1 will give you say 30% more power, but just be happy with the reliability factor of 23:1 (20% more power). Running higher afr's will result in alot less heat that the engine/radiator has to shed. Problem solved.

 

[ToyRoverlander]

nobody take this the wrong way but if this engine is known for having heat issues, what exactly makes it so crazy to put a larger radiator volume into the equation?

That's kinda what I did. I have a 3B in my Land Rover. In the mountains (on holiday, our country is flat as a pancake) it would get really hot. No power either as it was still NA. Didn't have a decent fan and shroud either.

When I fitted the turbo I wanted to have as much cooling capacity as possible. I knew the old 2.5na diesel defenders have a radiator that's the full width and height of the engine bay. Aftermarket ones are aluminium so that's what I've got. It's way bigger than what was in there.
As there's just no room for a mechanical fan I fitted two 12" SPAL electric fans. I choose those as they are good quality and these move some serious air.
I made sure the air that would hit the front of the rad would actually go through the rad, and not around it, by closing of the sides and top of the rad as much as possible.
There's a coolant temp switch in the bottom rad hose that switches on the fans at preset temps. I also have a switch on the dash to manually turn them on.

There's also an intercooler sitting right in front of the rad that does block a bit of airflow. The 3B runs at max fuel and about 19psi boost. When driving normal boost seldom gets over 14psi.
Truck weighs 4900lbs, 4.1s, 4speed and 33's.

When driving on the highway, 90kph when it's 35degrees C out there the fans don't come on and water temp sits at 90C. When it is 30degrees C, as long as I keep driving at least 30kph the fans don't come on and all is good. Only in slow traffic or when on hills the fans come on.
Cooling capacity has greatly improved over what it was.

 

[gerg]

I use evans waterles coolant so its naturally less effecient than 30/70 regular coolant. Without the trailer I could only get the temp up (215F) pulling the hardest part of the coquihalla doing 55mph with my foot to the floor (egt 1300F). To most other folks its just the steepest part at the end of a very very long steep hill. That hill is like 40kms long and about 8% at the end, roughly. Other than that it was always 190F. I have a Steve Austin grampa 3b runing 25lbs which I stuff as much crack down that poor bastards throat that the stock pump can deliver. It has reinforced ring lands stock with piston squirters. Pistons are also ceramic coated which I dont think makes a huge difference but it sounds cool and I tell grampa that it makes it all ok. Right now im replacing grampa's hip. And...im talkin about the Steve Austin that cost 6 mil, not the lame wrestler. Man I remember when a million dollars was actually alot of money. Here is a grade profile.


They are often working on the road and really chew it up. They post signs so its your own fault if you hapen to fly into the air while driving your snowmachine. And It doesnt look like that guys wearing a helmit.





I would consider putting an intercooler in front of a radiator with temp issues a WIN/loose situation. You would be better off I would guess, but its definately not a win/win. Yes it isnt an AC rad, but it will screw with your radiator effeciency in not a possitive way. This is just one of the reasons I like top mount intercoolers.

Yes an oil cooler will also screw with your rad effeciency if you put it in front of it. I was going to mount mine in my bumper wings or under my winch in a vented box. I forgot to mention that part sorry. I know that might sound weird, but I was toying with the idea of mounting it to my hood which sounds weirder. Im pretty sure my oil was getting just a wee tad hotter than my water.

g

 

[langsen]

1.The FJ60 fan clutch vs HJ60 clutch activation temps are both irrelevent at 210F so if fan clutch is my issue, my 2h has destroyied the new clutch with is awesome torque.

Well there's more to it than just engagement temp. There could also be a difference in the percent of shaft speed the fan turns at when engaged. For example, there are some fan clutches that turn at 40% of shaft speed, and some that turn at 70%. I don't know if the FJ and the HJ clutches are hugely different but they do have different part numbers for a reason. Also, AFAIK those two fan clutches are different lengths, so the position of the fan within the fan shroud could be different. Although this stuff may not make much of a difference it seems like every little bit helps, so I mention it. I know there are some threads on here that recommend adding extra silicone fluid even to new fan clutches if they are to be used in this type of climate.

Was it overheating at all before the turbo install?

How big is that pipe fitting that you have welded to the output flange, and how big is the downpipe?

 

[o8ko8k]

Well there's more to it than just engagement temp. There could also be a difference in the percent of shaft speed the fan turns at when engaged. For example, there are some fan clutches that turn at 40% of shaft speed, and some that turn at 70%. I don't know if the FJ and the HJ clutches are hugely different but they do have different part numbers for a reason. Also, AFAIK those two fan clutches are different lengths, so the position of the fan within the fan shroud could be different. Although this stuff may not make much of a difference it seems like every little bit helps, so I mention it. I know there are some threads on here that recommend adding extra silicone fluid even to new fan clutches if they are to be used in this type of climate.

Was it overheating at all before the turbo install?

How big is that pipe fitting that you have welded to the output flange, and how big is the downpipe?

that thread about the fluid replacement makes a bit more sense now Ive read a few of them and didnt quite get it. now i do. well i cant say for certain but at slow speeds my AC is ICE cold now (it wasnt b4). i have the original fan clutch and it is serviceable, the nappa special is riveted shut so its a pure use and throw away. So i can play with the stock one and not go without... =D

and yes I totaly apreciate it man, good to mention stuff even the little stuff, thats what this place is all about! i had my head so wrapped around engage temps i didnt even think about anything else!

i overheated worse b4 the turbo and the turbo made it LOTS better. Th output flange is 2". downpipe is 2.5"

 

[o8ko8k]

GREG:
WOW that grade profile is insane! your 3b is my hero! i was considering the evans fluid but holding off till a few other items are addressed. ya the intercooler install just has me stumped at the moment, i just keep circling on placement locations....

TOYLANDCRUISER:
totaly dig the radiator man! thanks for the photo. I think i will mock up a cardboard version of what im thinking and post it up. I dont feel like spending anything on the truck this month, as my wallet needs a break, but i think my idea is gonna help the heat big time.

All in all... delicious info folks! nom nom nom, burp, thankyou!

 

[ForealBoreal]

If you want some good reading on top mounts check out ARE out of Australia. They put up some hard numbers of what works and doesn't. Lots of data. Shaker top mount I do believe.

Also consider buying a quality core.
Treadstone performance has some cool baffled end tanks that can get efficiency up to 90%.

 

[Dougal]

A couple more points.

It's unrealistic to expect to keep coolant at 180F (what's that, 82C), it's more realistic to keep it from boiling at the worst case. A radiator system with a 15psi cap won't boil until around 120C (250F). However you need to make sure it dosen't boil in the engine and create steam pockets.
To cool your oil, consider putting fins on your engine sump. It's full of hot oil and exposed to a decent draft the whole time. Won't restrict the radiator.

What are your EGT? A large proportion of a diesel engines cooling is done by the air through the engine. Too much fuel makes this difficult.

Australians overheat these all the time. What solutions do they have?

 

[TheBigBoy]

Australians overheat these all the time. What solutions do they have?

Beer . We drink alot. Seems to fix all problems.

 

[o8ko8k]

Beer . We drink alot. Seems to fix all problems.

this is the best idea ive heard yet!

 

[o8ko8k]

A couple more points.

It's unrealistic to expect to keep coolant at 180F (what's that, 82C), it's more realistic to keep it from boiling at the worst case. A radiator system with a 15psi cap won't boil until around 120C (250F). However you need to make sure it dosen't boil in the engine and create steam pockets.
To cool your oil, consider putting fins on your engine sump. It's full of hot oil and exposed to a decent draft the whole time. Won't restrict the radiator.

First, Ive always been a fan of unrealistic, but regardless, you make an important point. im very much under 250F in all of this so maybe ill back up a bit in my obsessive pondering...

What temp is realistic to achieve in an all-out long hill climb?
And what temp is ideal?

What are your EGT? A large proportion of a diesel engines cooling is done by the air through the engine. Too much fuel makes this difficult.

1250F - 1300F on grade with trailer in tow. I can hardly get the EGT past 1000 when im not towing. and the 1300 happens slowly, 30 seconds sustained foot down (e.g 1000 slowly climbs to 1300), its not like it rockets to 1400+ immediately (like it did b4 the turbo was installed). which is what was leading me down the intercooler path, HOT air compressed to even HOTer, and constant for several minutes.

 

[Jan-78FJ40]

nobody take this the wrong way but if this engine is known for having heat issues, what exactly makes it so crazy to put a larger radiator volume into the equation?

I certainly apreciate all the suggestions as they are all very good ones and im asking for this kind of info and i collected a few things that i missed. Thats what the forum is all about too, others can read this and see the big list there in all its glory.

But PLEASE can someone/anyone take a look at the proposed analysis I did that concluded the stock one is too small and see if the results hold water or needs refinement? I think there is a fantastic argument in this thread that the stock radiator is not big enough for a turbo.

Thanks!

I put a high quality 4 core on my turboed 2H and it definitely helped. Not as much as the welded fan clutch though.

Still, even with all that I had to slow down on the highway when it got really hot outside, or on long inclines.

J

 

[Dougal]

First, Ive always been a fan of unrealistic, but regardless, you make an important point. im very much under 250F in all of this so maybe ill back up a bit in my obsessive pondering...

What temp is realistic to achieve in an all-out long hill climb?
And what temp is ideal?

1250F - 1300F on grade with trailer in tow. I can hardly get the EGT past 1000 when im not towing. and the 1300 happens slowly, 30 seconds sustained foot down (e.g 1000 slowly climbs to 1300), its not like it rockets to 1400+ immediately (like it did b4 the turbo was installed). which is what was leading me down the intercooler path, HOT air compressed to even HOTer, and constant for several minutes.

In metric I'd be happy keeping at or a little over 100C in the worst conditions. Call that 210-220F. But you must have a pressurised system to run that. Otherwise you'll just make steam.

It does sound like your EGT is following head temperature at least a little. Intercooling will help that. How much boost are you running?

I would lock up the old fan clutch and try that first. It's your cheapest and easiest test.

 

[langsen]

That map of the Arizona hills is pretty cool, I never saw it before. Steepest hill I've gone up was the short one from the Tonto Natural Bridge back to the main road. I think it's 14% but only about a mile long.

What speed / RPM are you at going up these hills? With my stock HJ60 I'm probably only going 45mph up a couple of those hills from Phoenix to Flagstaff. Never saw the stock gauge go above half, but I keep it light on the throttle and try to keep it around the torque peak at 2k RPM; I don't think I've ever revved it above 3k. I was planning on putting a turbo on it but this thread is making me worried.

If you decide to go with an oil cooler, the RX7 oil cooler is supposed to be good and has a built in thermostat too.