1JZ s13 cooling issue. Opinions and tips welcome.

[EthanR]

Hey guys, I BELIEVE I'm in the correct section, if not feel free to move/close it.

I have a 1JZ hatch, non VVTI. Some relevant (to this thread) mods are:

Big Mishimoto radiator
ISIS FMIC
AEM Standalone
Brand new water pump
2x Electric fans
DEFI Water temp gauge with DEFI probe

I'm having an issue to where when I come off the track from a run, my temperatures are extremely high. The DEFI gauges read in Celsius and typically the temp is anywhere between 100-110 (Rougly 212 - 230F) after exiting the track. That temperature is with me not running a hood or a front bumper. I've had it get to about 100 cruising around town too, bumper on with hood. We have it tuned to where the car will shut off after anything over 230F, it hasn't shut off yet but I have had my gauge read higher than 110C, all the way up to 115 once. The only things so far that have helped is to turn the car off almost immediately, or to throw ice cold water into my e-fans.

Part of the issue may be the e-fans, they are what I believe to be pullers, however they are mounted to the front of the radiator as pushers (they turn the correct way however). I can not fit any sort of electric fan in front of my engine however, or else I would run them as pullers.

So what are my options? I've tried water wetter (with absolutely zero result). I suppose I could cut into the core support to move the radiator forward to attach fans to the back, but I wanted to get some input. I'd like to run a bumper and hood again.

[BigPawr]

Well I'd first make sure you know what you have and that they are indeed working correctly. You stated you have efans that are pullers, but mounted in front of the radiator and operating as pushers. So that means you don't have puller fans. They sell fans that are only one type or both types depending on how you wire them. So if you aren't sure what you have and how they are working, clear that up first.

Second, if they are indeed pushing air through the radiator and still not getting the job done, you could invest into larger and or more effecient pusher fans. Something with better CFM rating.

Third you can reposition the radiator, whether that be cutting the core support to move forward, or buying a different size radiator that will mount more forward inside the core support. Keep in mind of the AC condenser if you are running that. If not then you have more room to play with. I'm planning to possibly run a scirocco style racing radiator inside my core support to allow room for puller fans with my 2J in an S14. That is just an idea of something that would possibly work in this scenario. You'll have to do measuring to make sure you pick a correct radiator to fit the way you need it.

[jr_ss]

Do you have any ducting what-so-ever? Track cars require proper ducting to stay cool.

Also sounds like to need high CFM fans and perhaps a folder T-stat to get the coolant flowing sooner through the engine.

[Kingtal0n]

Move the engine back some and re-think the configuration of the cooling system. Fit some fans behind the radiator and create some proper ducting. The height of the vehicle may come into play.

also consider your engine may be improperly tuned. Maybe the timing is retarded and the EGT's are blazing hot leaving your cooling system to take up the slack. Do you have an EGT gauge?

[EthanR]

Well I'd first make sure you know what you have and that they are indeed working correctly. You stated you have efans that are pullers, but mounted in front of the radiator and operating as pushers. So that means you don't have puller fans. They sell fans that are only one type or both types depending on how you wire them. So if you aren't sure what you have and how they are working, clear that up first.

Second, if they are indeed pushing air through the radiator and still not getting the job done, you could invest into larger and or more effecient pusher fans. Something with better CFM rating.

Third you can reposition the radiator, whether that be cutting the core support to move forward, or buying a different size radiator that will mount more forward inside the core support. Keep in mind of the AC condenser if you are running that. If not then you have more room to play with. I'm planning to possibly run a scirocco style racing radiator inside my core support to allow room for puller fans with my 2J in an S14. That is just an idea of something that would possibly work in this scenario. You'll have to do measuring to make sure you pick a correct radiator to fit the way you need it.

Thanks for the smaller radiator idea, that's something I (stupidly enough) didn't consider. I just have to figure out what will fit in there. As far as my current fans go, they are wired up correctly and are pushing air. I've heard two things however, I don't know if you can confirm or debunk these though. Since my fans were originally supposed to be pullers, they won't work as good as ones that were MEANT to be pushers. Can you confirm? Also, I've heard that pullers were way better than pushers as far as cooling goes.

Do you have any ducting what-so-ever? Track cars require proper ducting to stay cool.

Also sounds like to need high CFM fans and perhaps a folder T-stat to get the coolant flowing sooner through the engine.

No ducting, since I run no front bumper and usually no hood there isn't really anything I can duct, if that makes sense. I.e. - no body work to attach the ducts to. I do want to make a plate that goes from my front mount to the bottom of my core support though, from what I hear there's a low pressure area that causes turbulence, and I'm sure the fans do the same.

Move the engine back some and re-think the configuration of the cooling system. Fit some fans behind the radiator and create some proper ducting. The height of the vehicle may come into play.

also consider your engine may be improperly tuned. Maybe the timing is retarded and the EGT's are blazing hot leaving your cooling system to take up the slack. Do you have an EGT gauge?

Engine tune is great, I do have an EGT gauge en route but it isnt here yet

[jdm styles]

v mount took all my problems away 1j s13

[jubee-s13-g35]

Hey you can pm me if you have more questions but I may have your solution. I had a 1jz in a s13. I am now moving it into a s14 chasis. I am in miami. My build post is coming as soon as I finish it but back to the question at hand. You cooling issues can be solved. I would buy a thermostat that opens cooler. When you get it pm me so I can show you a trick. Also I would get actual spal pusher fans. Spal have about the most cfm that I have seen in slim fans. Compared to the ones you can pick up at autozone or discount and others that summit or Murray's sell. After you get the thermostat and do the trick try the fans after. But I'm sure the thermostat would help. I had he same problem with my 1jx inside a s13 hath with a/c tripple core champion radiator with the support cutbacks bit and flex a lites. Your radiator is smaller and i dont think you have ac so ou should be fine. Pm me if I sound too confusing.

[EthanR]

v mount took all my problems away 1j s13

Thats the plan for this winter :) Or rear mounted radiator if I want to get crazy, but for this season I just want to be able to drive. I don't have any welding/fabrication skills so I would have to outsource. Unfortunately that takes too much time right now!

Hey you can pm me if you have more questions but I may have your solution. I had a 1jz in a s13. I am now moving it into a s14 chasis. I am in miami. My build post is coming as soon as I finish it but back to the question at hand. You cooling issues can be solved. I would buy a thermostat that opens cooler. When you get it pm me so I can show you a trick. Also I would get actual spal pusher fans. Spal have about the most cfm that I have seen in slim fans. Compared to the ones you can pick up at autozone or discount and others that summit or Murray's sell. After you get the thermostat and do the trick try the fans after. But I'm sure the thermostat would help. I had he same problem with my 1jx inside a s13 hath with a/c tripple core champion radiator with the support cutbacks bit and flex a lites. Your radiator is smaller and i dont think you have ac so ou should be fine. Pm me if I sound too confusing.

Well, I will try to find me a lower temp thermostat. As for the fans you have, what model are they? Pushers or pullers?

[d_nice]

^^^ that what I was think was the thermostat. let me know if that works,

[fliprayzin240sx]

What kind of fans are they? Are they the generic basket style fans? If they are, try going with some shrouded dual FAL fans, put them in front of the rad and make sure they're absolutely sealed around the radiator.

[EthanR]

What kind of fans are they? Are they the generic basket style fans? If they are, try going with some shrouded dual FAL fans, put them in front of the rad and make sure they're absolutely sealed around the radiator.

Yeah I'm fairly sure it's some ISIS shit, but shrouded? Will-do. Tbh I don't know anything about cooling so I thought the more air that is able to pass through the radiator the better - a shroud would only limit it through those two holes right?

I know it sounds stupid but it's a question I have to know haha.

[EthanR]

Also, a friend told me this but can anyone confirm? he said that typically fans with curved blades are meant to be pullers.

So if I'm looking for pushers, I'm looking for straight-blades?

[Zerolift Autolab]

Maybe I missed it in the thread history.
But, what radiator is it? For KA or for SR

If its for KA with the 2 outlets on the same side the JZ motors will
have cooling issues due to not using the full surface of the radiator to cool.

If its a SR Rad you should have a cross over hose from driver to passenger side
for the upper water neck, and the radiator will use its full surface to cool side to side.

We recently finished a 2JZGTE VVTI S13 project using a Koyo N Flow Radiator with a set of the Flex A Lite 420 puller fans. We also installed an upgraded thermostat for good measure.
This setup has no overheating issues what so ever.

Feel free to contact me at [email protected] if I can help with anything.
Thanks

[EthanR]

Maybe I missed it in the thread history.
But, what radiator is it? For KA or for SR

If its for KA with the 2 outlets on the same side the JZ motors will
have cooling issues due to not using the full surface of the radiator to cool.

If its a SR Rad you should have a cross over hose from driver to passenger side
for the upper water neck, and the radiator will use its full surface to cool side to side.

We recently finished a 2JZGTE VVTI S13 project using a Koyo N Flow Radiator with a set of the Flex A Lite 420 puller fans. We also installed an upgraded thermostat for good measure.
This setup has no overheating issues what so ever.

Feel free to contact me at [email protected] if I can help with anything.
Thanks

Thanks for the response. It's an SR rad, whatever mounts came with the swap position the engine just a bit too far forward to mount pullers =/

PRETTY sure it's a Tech2 kit, not sure though.

I'm going to get a low-temp thermostat and form FAL shrouded pushers and see how it works. thanks for all of the help everyone :)

I'll report back afterwards.

[thefro526]

I'm having an issue to where when I come off the track from a run, my temperatures are extremely high. The DEFI gauges read in Celsius and typically the temp is anywhere between 100-110 (Rougly 212 - 230F) after exiting the track. That temperature is with me not running a hood or a front bumper. I've had it get to about 100 cruising around town too, bumper on with hood. We have it tuned to where the car will shut off after anything over 230F, it hasn't shut off yet but I have had my gauge read higher than 110C, all the way up to 115 once. The only things so far that have helped is to turn the car off almost immediately, or to throw ice cold water into my e-fans.


Quick question, do have data from a track session where you've run with a hood and bumper? IMO, that might be part of your problem, but it's hard to tell. If you can imagine, while your car is in motion, a hood and bumper act as this sort of air duct to keep air moving over the radiator which will help to remove some heat. Without a hood in place, it's very likely that some air is hitting the radiator and going around/over it rather than through it.

Although, with that being said, if your heating situation worsens when running with a hood, then that means that your engine bay is too cluttered/tight to allow a smooth path for air flow - which seems to be pretty common with I6 S-Chassis. If this is the case, an easy way to try reduce the under-hood temps is to space up the rear of the hood, which should give the air that's gone through the radiator somewhere to go.

Vented hoods are also a solid option too, a good one helps to draw through the radiator when the car is in motion.

When I started doing research for my swap way back when, a lot of the JZ guys were having similar heating issues, most of which seemed to be a result of physically not being able to remove enough heat through the standard radiator without a pretty beefy fan setup or something else. One thing that I've seen that will help, or is said to help, is deleting the stock oil cooler and running an external cooler.

From the factory 1JZ's (and 2J's I think) have this weird oil cooler built into the filter housing. It taps into the main external line that runs around the block from the water pump to just above the oil filter outlet on the block. Before the line goes into the block, it goes through the oil cooler, which should 'in theory' cool the oil down some, but if you can imagine, hot coolant doesn't really cool hot oil that much, and if anything the hot oil is heating the coolant more. The idea is that a separate external cooler will help to remove heat from the system by essentially adding an additional smaller radiator, and the oil won't be 'forced' to heat the coolant... Or something like that.

Also, FWIW, like a bunch of people have said before, Ducting seriously makes a difference. I mocked my ducting up on the car a while back, and noticed huge gains in negative pressure in front of the car with the fans on. Prior to the ducting, I setup a series of tape strips at the lower opening of my bumper (pignose) and in the upper openings (cutouts) to see what kind of air my fans were drawing. As far as I could tell, the tape didn't move at all when the fans were turned on - after adding the ducting the same tape strips moved in towards the radiator noticeably, maybe ~.5" - .75". This meant, in a round about way, that any air that entered the cutouts in my front bumper was forced to go into the radiator (ignoring any leaks).

Any who, this post was way longer than I planned, sorry... Lol.

[EthanR]

Quick question, do have data from a track session where you've run with a hood and bumper? IMO, that might be part of your problem, but it's hard to tell. If you can imagine, while your car is in motion, a hood and bumper act as this sort of air duct to keep air moving over the radiator which will help to remove some heat. Without a hood in place, it's very likely that some air is hitting the radiator and going around/over it rather than through it.

Although, with that being said, if your heating situation worsens when running with a hood, then that means that your engine bay is too cluttered/tight to allow a smooth path for air flow - which seems to be pretty common with I6 S-Chassis. If this is the case, an easy way to try reduce the under-hood temps is to space up the rear of the hood, which should give the air that's gone through the radiator somewhere to go.

Vented hoods are also a solid option too, a good one helps to draw through the radiator when the car is in motion.

When I started doing research for my swap way back when, a lot of the JZ guys were having similar heating issues, most of which seemed to be a result of physically not being able to remove enough heat through the standard radiator without a pretty beefy fan setup or something else. One thing that I've seen that will help, or is said to help, is deleting the stock oil cooler and running an external cooler.

From the factory 1JZ's (and 2J's I think) have this weird oil cooler built into the filter housing. It taps into the main external line that runs around the block from the water pump to just above the oil filter outlet on the block. Before the line goes into the block, it goes through the oil cooler, which should 'in theory' cool the oil down some, but if you can imagine, hot coolant doesn't really cool hot oil that much, and if anything the hot oil is heating the coolant more. The idea is that a separate external cooler will help to remove heat from the system by essentially adding an additional smaller radiator, and the oil won't be 'forced' to heat the coolant... Or something like that.

Also, FWIW, like a bunch of people have said before, Ducting seriously makes a difference. I mocked my ducting up on the car a while back, and noticed huge gains in negative pressure in front of the car with the fans on. Prior to the ducting, I setup a series of tape strips at the lower opening of my bumper (pignose) and in the upper openings (cutouts) to see what kind of air my fans were drawing. As far as I could tell, the tape didn't move at all when the fans were turned on - after adding the ducting the same tape strips moved in towards the radiator noticeably, maybe ~.5" - .75". This meant, in a round about way, that any air that entered the cutouts in my front bumper was forced to go into the radiator (ignoring any leaks).

Any who, this post was way longer than I planned, sorry... Lol.

Thanks for the response! :)

TBH I don't have any data at all anymore, it was all deleted - however I don't really remember if I had the same issue with a hood or not. Next event I'm definitely going to try to run a hood with the rear spaced up, though I will say when I was cruising around town with a hood and bumper I was having an issue for sure.

An oil cooler was another thing I was thinking of, if I remember correctly the stock "oil cooler" runs under the block or something crazy. I think that deleting it will make a huge difference if I run an aftermarket one. Thanks for the suggestion!!

[thefro526]

Thanks for the response! :)

TBH I don't have any data at all anymore, it was all deleted - however I don't really remember if I had the same issue with a hood or not. Next event I'm definitely going to try to run a hood with the rear spaced up, though I will say when I was cruising around town with a hood and bumper I was having an issue for sure.

An oil cooler was another thing I was thinking of, if I remember correctly the stock "oil cooler" runs under the block or something crazy. I think that deleting it will make a huge difference if I run an aftermarket one. Thanks for the suggestion!!

Not a problem, I kind of nerd about things like this.

Sounds like you've got a plan though, try out different things under the same or similar conditions and see what they do. Each setup is a little bit different, so what works for some may not work as well or at all for you and visa versa. Also, change one thing at a time if you can - some people get caught up changing 2 or 3 things at once, and then you never really know what 'fixed' the problem.

Here's a random picture from the net that shows the oil cooler block and oil filter pretty well: (Intake manifold was removed)

http://i28.photobucket.com/albums/c239/cfinch702/P6120167.jpg

To eliminate the cooler, you can more or less just loop the water line into the block without ever going through the cooler assembly - from there you can run a sandwich plate or whatever to run the external cooler.

If you want to eliminate the cooler assembly entirely (worthwhile, IMO) then you'll need to find a pass through stud for the oil outlet in the block. IIRC, it's a 3/4-16 Thread, and needs to be approximately 1" long with ~12-13mm hole (1/2") through the center. There's a ford part number that fits the bill - it's E8ZZ-6890-A, or you can make your own like I did:

http://thefro526.files.wordpress.com/2010/11/img_0625.jpg?w=640&h=478

If you've got access to a lathe or similar, making your own is trivial, I bought a 12" long threaded rod and had it all done for less than the cost of the ford part.

[EthanR]

Not a problem, I kind of nerd about things like this.

Sounds like you've got a plan though, try out different things under the same or similar conditions and see what they do. Each setup is a little bit different, so what works for some may not work as well or at all for you and visa versa. Also, change one thing at a time if you can - some people get caught up changing 2 or 3 things at once, and then you never really know what 'fixed' the problem.

Here's a random picture from the net that shows the oil cooler block and oil filter pretty well: (Intake manifold was removed)

http://i28.photobucket.com/albums/c239/cfinch702/P6120167.jpg

To eliminate the cooler, you can more or less just loop the water line into the block without ever going through the cooler assembly - from there you can run a sandwich plate or whatever to run the external cooler.

If you want to eliminate the cooler assembly entirely (worthwhile, IMO) then you'll need to find a pass through stud for the oil outlet in the block. IIRC, it's a 3/4-16 Thread, and needs to be approximately 1" long with ~12-13mm hole (1/2") through the center. There's a ford part number that fits the bill - it's E8ZZ-6890-A, or you can make your own like I did:

http://thefro526.files.wordpress.com/2010/11/img_0625.jpg?w=640&h=478

If you've got access to a lathe or similar, making your own is trivial, I bought a 12" long threaded rod and had it all done for less than the cost of the ford part.

Awesome!! You've been a huge help! One question though, right now I'm already running a sandwich plate at the moment for my Oil Temp and Oil Press. gauges, do you think eliminating the stock cooler is necessary? Or would it be okay to just run it off my existing sandwich plate?

[fliprayzin240sx]

Well, dunno if 1JZs have the same issue as RBs but the oil filter snout is pretty short. When you use a sandwich block in between the filter and the filter block, the piece you thread on has a tendency to only thread on to a few threads. I have snapped the stock snout, filter fell off and loss all oil pressure before.

This is how I deleted the stock oil filter block...
Installing an oil cooler on an RB25DET (http://www.nicoclub.com/archives/rb25-oil-cooler-installation.html)

[EthanR]

Ah, I see what you're saying - but I actually have tons of room before I run into any sort of issue with that (surprisingly).

[thefro526]

Awesome!! You've been a huge help! One question though, right now I'm already running a sandwich plate at the moment for my Oil Temp and Oil Press. gauges, do you think eliminating the stock cooler is necessary? Or would it be okay to just run it off my existing sandwich plate?

I've seen dudes run a sammich plate and filter on the stock cooler before with no issues and others run the same setup with an external cooler off of the sandwich plate and it seems to work. Personally, I'm all for cleaning stuff up wherever I can, so that's why I removed the stock cooler in favor of an external, but it isn't really 'that' big of a deal.