Hello everybody...
It may look that some oem factory parts don't do much or don't play a major role in a properly operating automotive system such as the coolant system of a car.
In our case we do want to view the issue that JZ (1jz or 2jz) swaps takes a lot of space and limits the radiator area since the IC pipe goes down from the TB of the intake manifold and totally fouls the two or one small secondary stock oem electric fans. With an upgraded big radiator it totally fouls the fan shroud or even the radiator it self. Or any 7M guys that take off or do not use the 2 secondary electric fans...
Since most of the JZ swapped guys have an upgraded thick radiator we can only go one route as I also did, and take two steps.
1)2JZ-GE fan, which will position the offset of the fan blades towards the engine about 1inch. Many guys do cut and mod the upper water neck and cut it 1 inch and re-weld it back to mate with the re positioning of the fan itself.
2)2JZ-GE or 2JZ-GTE fan clutch.
Here you can see my parts, the new rad and the x2 oil coolers 16 row since I ditched the oem small sandwitch/oil filter combo.
The 2JZ-GE fan
A new engine under cover unit
And here is everything installed , as you can take a look , you can observe the modded upper neck being 1 inch shorter and of course the oem 7M shroud on.
My set up is :
New performance 2 row radiator, new oem mechanical fan, new 12'' inch spal electric push type fans behind the radiator, new Toyota red coolant.
Blitz 1.3 bar radiator cap, new oem engine undercover plastic, and new push type 10' inch electric fan on the A/C condenser, and stock fan shroud,
and last an upgraded carbon Stout hood with air ducts to vent the hot engine bay air out.
--------------------------------------------------------------------------------------
So, now we can fit that big radiator in there...but it's not over yet folks.
Since I knew that a big radiator would not do much if other parts and operating systems are not working properly or efficiently.
In my 2nd post I will explain the issues I encountered...
With a 1st look you'll see that everything is perfectly done, and this is what I thought for my self also.
And true I always buy very good performance parts, and usually top brand names. I took every precaution possible and installed everything properly.
The oil coolers over and behind the left and right front fog lights where I have air ducts for cooling them, so they won't get in front of the IC , Condenser and Radiator.
I knew I don't have the two small oem stock electric fans anymore so I did replace this loss with installing 2 big 12'' inch spall electric fans in front of the radiator and between the condenser. It will fit only if you use some slim ones. These fans are push style fans and their rotation can be reversed. This two fans are triggered by a switch via relay/ 30AMP fuse.
The two 12 '' inch electric fans on the radiator
The oil cooler behind the front fog light away from the frontal area of the main radiator.
So, we are all good. But no. In the summer on hot days or idling long time in traffic or with the A/C on the coolant temperature was rising.
Almost every time I was in the 205-215 F' temps zone with the 2 big electric fans engaged of course. Two years on looking and trouble shooting I couldn't find a solution.
Always used Toyota red coolant, Sard 68' Celcious thermostat, new coolant hoses, turbo blanket, titanium heat wrapped down pipe, and thermal coating on my HKS exhaust manifold, and last I got a carbon Stout hood which has air ducts for venting the hot engine bay out and of course it looks nice , and an S2 air duct for the front bumper.
Last I made my custom turbo A duct on the front bumper for more air entry to the radiators...
Here you can see my modded front bumper with the side air ducts and the main turbo A look alike, and of course the Stout hood.
Still the hot coolant temps where present on hot days idling in traffic using my A/C will run hot (210 F -220 F sometimes), after all these mods.
Of course when cruising or pulling on the highway no issues while temps go down around 190. So I thought
- the frontal air stream is not sufficient when idling or doing low speeds
- engine bay heat is somehow disturbing my rad/fan proper cooling.
So, I took a very careful eye shot to my engine bay and discovered some small but very important issues...
1) my oem 7M fun shroud was modified/cut where the two electric fans used to be, leaving all that space uncovered as the Thread starter mentioned is not good and he is totally right about it.
2) the shroud itself has some cracks and it's alignment / seal over the radiator is gone since it was cut and it's structure has softened.
3) the no.2 fan shroud is ACTUALLY missing since for ever. It's the lower piece that mates with the upper round piece.
4) after I installed the Stout hood I never put back the front rubber weather seal on the front of the hood which actually prevents the engine bay 's heat to recycle with the cool air that the mechanical fan pulls through the radiator.
5) last I should engage the two big 12' inch elec. fans earlier and not when I reach the 210 zone, since by that time the heat soak would be at it's peak, and the electric fans would struggle to maintain the temps not to mention bringing them down.
I haven't tried to fix any of these issues since I don't have the part required to solve my issues. But I ordered them today from the dealer. Overnight parts from Japan!
I ordered the single fan MA70 shroud that was used on the N/A 86-88' models, if there where a blanked one I would have got that one...
Anyway, I will try to cover the single hole or maybe I would put a powerful aftermarket pull type electric fan there instead...I will see.
For sure I will seal 100% the perimeter of the fan shroud since engine bay hot air shouldn't go through. And maybe I will make an extension of the circled shroud area towards the upper engine coolant hose to cover completely the fan blades and isolate the cooling process. And last I will put that oem front hood seal back on!
Here is the one hole oem 7M-GE shroud...
On the above picture you can see the plastic line/wall that isolates completely the two areas. Big mechanical fan area vs small electric fan area.
Even that... this setup doesn't have a 2nd small electric fan at the bottom...take a look how that area is used to pull heat from the radiator by the big mechanical fan and is totally isolated !
To resume, as the forum member and OP thread starter mentioned...Close shroud structure is a must! If it has not electric fans the holes should be close and make a vacuum area for the oem mechanical puller fan to extract heat from the radiator. This is proven as the Toyota factory DOES on their shrouds that not use any small secondary electrical fans... Here is a picture of a SC300 fan shroud, almost the same as the mk4 Supra non turbo fan shroud.
I will keep you posted about the results when I am done...and post the results.
Tell me your thoughts, your setup that cools down properly the engine, and works good for you..or any other tips you can share!
It may look that some oem factory parts don't do much or don't play a major role in a properly operating automotive system such as the coolant system of a car.
In our case we do want to view the issue that JZ (1jz or 2jz) swaps takes a lot of space and limits the radiator area since the IC pipe goes down from the TB of the intake manifold and totally fouls the two or one small secondary stock oem electric fans. With an upgraded big radiator it totally fouls the fan shroud or even the radiator it self. Or any 7M guys that take off or do not use the 2 secondary electric fans...
Since most of the JZ swapped guys have an upgraded thick radiator we can only go one route as I also did, and take two steps.
1)2JZ-GE fan, which will position the offset of the fan blades towards the engine about 1inch. Many guys do cut and mod the upper water neck and cut it 1 inch and re-weld it back to mate with the re positioning of the fan itself.
2)2JZ-GE or 2JZ-GTE fan clutch.
Here you can see my parts, the new rad and the x2 oil coolers 16 row since I ditched the oem small sandwitch/oil filter combo.
The 2JZ-GE fan
A new engine under cover unit
And here is everything installed , as you can take a look , you can observe the modded upper neck being 1 inch shorter and of course the oem 7M shroud on.
My set up is :
New performance 2 row radiator, new oem mechanical fan, new 12'' inch spal electric push type fans behind the radiator, new Toyota red coolant.
Blitz 1.3 bar radiator cap, new oem engine undercover plastic, and new push type 10' inch electric fan on the A/C condenser, and stock fan shroud,
and last an upgraded carbon Stout hood with air ducts to vent the hot engine bay air out.
--------------------------------------------------------------------------------------
So, now we can fit that big radiator in there...but it's not over yet folks.
Since I knew that a big radiator would not do much if other parts and operating systems are not working properly or efficiently.
In my 2nd post I will explain the issues I encountered...
With a 1st look you'll see that everything is perfectly done, and this is what I thought for my self also.
And true I always buy very good performance parts, and usually top brand names. I took every precaution possible and installed everything properly.
The oil coolers over and behind the left and right front fog lights where I have air ducts for cooling them, so they won't get in front of the IC , Condenser and Radiator.
I knew I don't have the two small oem stock electric fans anymore so I did replace this loss with installing 2 big 12'' inch spall electric fans in front of the radiator and between the condenser. It will fit only if you use some slim ones. These fans are push style fans and their rotation can be reversed. This two fans are triggered by a switch via relay/ 30AMP fuse.
The two 12 '' inch electric fans on the radiator
The oil cooler behind the front fog light away from the frontal area of the main radiator.
So, we are all good. But no. In the summer on hot days or idling long time in traffic or with the A/C on the coolant temperature was rising.
Almost every time I was in the 205-215 F' temps zone with the 2 big electric fans engaged of course. Two years on looking and trouble shooting I couldn't find a solution.
Always used Toyota red coolant, Sard 68' Celcious thermostat, new coolant hoses, turbo blanket, titanium heat wrapped down pipe, and thermal coating on my HKS exhaust manifold, and last I got a carbon Stout hood which has air ducts for venting the hot engine bay out and of course it looks nice , and an S2 air duct for the front bumper.
Last I made my custom turbo A duct on the front bumper for more air entry to the radiators...
Here you can see my modded front bumper with the side air ducts and the main turbo A look alike, and of course the Stout hood.
Still the hot coolant temps where present on hot days idling in traffic using my A/C will run hot (210 F -220 F sometimes), after all these mods.
Of course when cruising or pulling on the highway no issues while temps go down around 190. So I thought
- the frontal air stream is not sufficient when idling or doing low speeds
- engine bay heat is somehow disturbing my rad/fan proper cooling.
So, I took a very careful eye shot to my engine bay and discovered some small but very important issues...
1) my oem 7M fun shroud was modified/cut where the two electric fans used to be, leaving all that space uncovered as the Thread starter mentioned is not good and he is totally right about it.
2) the shroud itself has some cracks and it's alignment / seal over the radiator is gone since it was cut and it's structure has softened.
3) the no.2 fan shroud is ACTUALLY missing since for ever. It's the lower piece that mates with the upper round piece.
4) after I installed the Stout hood I never put back the front rubber weather seal on the front of the hood which actually prevents the engine bay 's heat to recycle with the cool air that the mechanical fan pulls through the radiator.
5) last I should engage the two big 12' inch elec. fans earlier and not when I reach the 210 zone, since by that time the heat soak would be at it's peak, and the electric fans would struggle to maintain the temps not to mention bringing them down.
I haven't tried to fix any of these issues since I don't have the part required to solve my issues. But I ordered them today from the dealer. Overnight parts from Japan!
I ordered the single fan MA70 shroud that was used on the N/A 86-88' models, if there where a blanked one I would have got that one...
Anyway, I will try to cover the single hole or maybe I would put a powerful aftermarket pull type electric fan there instead...I will see.
For sure I will seal 100% the perimeter of the fan shroud since engine bay hot air shouldn't go through. And maybe I will make an extension of the circled shroud area towards the upper engine coolant hose to cover completely the fan blades and isolate the cooling process. And last I will put that oem front hood seal back on!
Here is the one hole oem 7M-GE shroud...
On the above picture you can see the plastic line/wall that isolates completely the two areas. Big mechanical fan area vs small electric fan area.
Even that... this setup doesn't have a 2nd small electric fan at the bottom...take a look how that area is used to pull heat from the radiator by the big mechanical fan and is totally isolated !
To resume, as the forum member and OP thread starter mentioned...Close shroud structure is a must! If it has not electric fans the holes should be close and make a vacuum area for the oem mechanical puller fan to extract heat from the radiator. This is proven as the Toyota factory DOES on their shrouds that not use any small secondary electrical fans... Here is a picture of a SC300 fan shroud, almost the same as the mk4 Supra non turbo fan shroud.
I will keep you posted about the results when I am done...and post the results.
Tell me your thoughts, your setup that cools down properly the engine, and works good for you..or any other tips you can share!
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