Normal Operating Temperature for RB25DET

[streeteg]

Just curious as to what the normal temp is for an RB25det. WHen im cruisin on the highway it stays roughly at 180, but in traffic it can get to about 200ish.

This is on an autometer gauge hooked in line with a custom heater hose on my 74 260z...

TIA

Eric

[BoostFab]

200f is on the high side. idling should be closer to 180f. how's your fan setup ?

[l0nestar]

As Stated Previously:

170*f / 77*c Thrilled 180* / 83* Happy 190* / 88* Content 200* / 93* Eek +* +* Sad

[streeteg]

Twin electric fans, suck through.... dont have much way for heat to escape.... as FMIC is taking up all front air dam space...

I do however have a funky hose setup---- because the RB has hoses for inlet/outlet on the same side and my radiator has the inlet on the top passenger and outlet on the bottom driver. not sure if that matters

[neonbomb]

Your fans should be cooling that reguardless of your hoses. Since you probably have no front air dam left, make a shroud and that will help a lot. As a last resort, or the non-free route, get an oil cooler or a vented hood . You can run an rb with one fan fine if you have a vented hood believe it or not. (DD that is)

[streeteg]

Hood actually has a scoop in it, and a vent over the turbo.... Its a custom piece to fit the other body modifications so I am not really a fan of modding more. Heres a picture....

[Makenski]

you done any ducting work to prevent air to go anywhere else cept through the rad?

[streeteg]

hmmm not a bad idea... but at cruising its perfectly fine... its when it sits @ idle....

Is it too outlandish to put I/C Sprayers on my rad?? ha anything to keep her safe

[l0nestar]

How big is your FMIC? Have you checked the piping on your FMIC to see if you even need to worry about the temps? Is it warm / hot to the touch? I assume you are looking into heatsoak.

[streeteg]

intercooler temp is cool as a cucumber even after some heavy boost. Im jsut more concerned about the health of the motor under such temps

[rb25drag]

Go to your local parts store and get a bottle of be cooling for your radiator, Its suppose to drop temps way down in the coolant. This should help you out alot.

[HxC_Nismo]

try to make ducts from your intercooler to the outer edges of your radiator so you don't have any air going elsewhere. and go with a coolant additive like rb25drag stated, i personally use redline water wetter

[Kansei240sx]

It depends on how much rust and **** has built up in your coolant jackets over time as those JDM motors sit forever in wrecker yards.

I have a single row Koyo SR20DET copper radiator, FAL 220's pulling through and a thermostatic controller for them so they kick on as needed and i run around a 85*C average. Which is around 180ish.

Sitting around it drops even cooler to about 80*C.

200*c is a tad on the warm side, but depending on where you're at the pressures above sea level and your radiator cap can raise the boiling point of water up to 240-250 degree's and the boiling point of ethylene glycol ( antifreeze) is a little higher.

[streeteg]

So after redoing coolant lines, and a flush I drove the car around for a little bit and it didnt want to stay sub 200. The best i could get was 195 while cruising but I still cant figure out why its running so hot-- I will try to rebleed again this weekend but its realy bothering me- The last thing I want to do is pop my motor from overheating.

It was getting to 210+ when sitting. Granted it was 95 degrees out but still--

[USMCgetsome]

something is wrong with the fans and also what type of oil are u running? 10/30 15/50? I'd check to see how fast those fans are spinning and check the voltage going to the fan. Your alternator may not be able to support the voltages needed for the fans to keep spinning quickly at idle. I also agree about bleeding the coolant system repeatedly. last but not least has the headgasket ever been changed?

are u using the stock oil cooler? i agree with above post of implementing an oil cooler.
Modified by USMCgetsome at 11:21 PM 8/17/2009

[Thanielson]

you mite want to try geting a nismo low temp t-stat to i have one and mine run's 160 at the hotest on a 90 to 100 deg day normal for mine is like 150.

have a nismo low temp t-stat and 2 10in fan's pulling no hood vent's oem 240sx radiator.

[GTS-T 240]

also make sure you cooling system is bled good, i was having problems getting the bubbles out of my system till i put on my greddy intake.

[streeteg]

Low temp thermo ordered--- I might be worried about cold winters here in the northeast --- but it still cant hurt.

[eh?]

Do you have a pic of your engine bay? Do you have pushers or pullers? What which radiator?

[Neejay]

A lot of guys recommend against it. Check out this thread I made:

http://www.skylinesaustralia.c....html

[streeteg]

Do you have a pic of your engine bay? Do you have pushers or pullers? What which radiator?

I have an aftermarket radiator with Pullers. 2 with no shroud--

[streeteg]

A lot of guys recommend against it. Check out this thread I made:

http://www.skylinesaustralia.c....html

I read the thread and it didnt really have too many people going against itjust that there were other ways to keep temps down. Which for me are not working. I will be using an additive, making a shroud, and potentially getting bigger fans. On top of that bleeding the system.

Like the thread says I crammed a big motor into a bay that was not supposed ot have it not to mention have a restrictive front end when it comes to air passing through.

[eh?]

I have an aftermarket radiator with Pullers. 2 with no shroud--

You need to upgrade those baby fans dude. Upgrade to some flex-a-lite 220 or altima fans. At least get some sort of fan that is shrouded. I can guarantee a big drop in temps with the fal 220.

[S14-NEO]

i am running a set a FAL 240 series i believe which are pusher style not pullers...mine mount in the front of the radiator instead of the normal location. I live in florida where it gets balls hot outside with insane humidity and my car runs just fine.. onlt time it gets on the warm side is when i am pushing it really hard in the heat of the day or if i am on the interstate . my temps are usually in the 85c range in town and that is very good. on the highway it can get up to the 90c range which i dont like but again thats also in the heat of the day too... at night it wont get that hot , tops 87c.

[streeteg]

You need to upgrade those baby fans dude. Upgrade to some flex-a-lite 220 or altima fans. At least get some sort of fan that is shrouded. I can guarantee a big drop in temps with the fal 220.

Ya that I definately knew. I have to take measurements this weekend and then I will get some beefy fan(s) to improve airflow.

[eh?]

How does the radiator look inside? I used this kit and got a ton of junk out of the radiator and engine

[streeteg]

Ive never seen that before... how does it work. That would be a good thing to have this weekend when I do the thermo, rebleed, and add water wetter...

[eh?]

You would use it in conjunction with their flush treatments. Basically you place the tee in the line that goes to the heater core and the yellow spout goes in the radiator neck. You connect a garden hose to the tee and with the engine running you run fresh water through the system.

[streeteg]

Ya I am definately going to do that this weekend. I am sure with new fans, a shround, additive, a flush, and a low temp thermostat my car will be good to go for a while....

Thanks for the help guys--- im shooting for 175-180

[gawdzilla]

you mite want to try geting a nismo low temp t-stat to i have one and mine run's 160 at the hotest on a 90 to 100 deg day normal for mine is like 150.

have a nismo low temp t-stat and 2 10in fan's pulling no hood vent's oem 240sx radiator.

i'd check the accuracy of your gauge