Please help me understand oil cooler.

[MarusGTR]

The car will never be a DD. I didn't check to see if the cooler had a thermostat as it wasn't a requirement.
Ideally I'd like to get rid of it to keep things simple, make some space and one less opportunity for leaks or contaminating the oil should the water-to-oil cooler fail.
I'm assuming you were kidding about using it as an additional means of taking heat away from the coolant.

Nope not kidding, seems like Cortex agrees because he just basically said the same thing as me :P

And by DD I meant street since without the thermostat you might not get enough heat into the oil from simply idling. Without enough heat it'll fail to keep at running temp.

Id keep the heat exchanger simply because it uses heat from the water to help heat up the oil faster , once everything is heated up the it alo supplements the oil cooler to help keep the oil temps under check .

EDIT: Yeah ok, I might not have wrote my earlier bit very clearly (I just made a foot long hole out of my Sentra's rocker panel in an attempt to fix it myself since I can't afford bodywork, so I think I'm a bit over my head with it) but yes, if you think of the engine as a thermal system, the engine needs to produce and transmit enough heat to the oil to get to its running temperature (that property is called specific heat). If you cooler has no thermostat and is efficient, it can take most of the heat away from the oil enough so that it'll never reach the required temperature.

With the water to oil exchanger you get an additional heat input into the oil if the oil temp is < water temp. But if the water loses enough heat (high differencial between oil and water) through the transfer its temperature will drop in the process.

[bobbo]

I know "Imation" removed his and I haven't spoken to him to see how it's working for him.
If the norm is to keep the water/oil cooler than I'll do just that. No point in reinventing the wheel.

[cortexx]

Hi Bobbo

There seems to be more reason to leave it there than remove it . In my opinion there are alot of things on these cars that people rip out without giving it much thought . HICAS is a prime example. I'll never remove mine, and if it has a problem then ill fix it not junk it . Nissans design engineers built this car the way they did for a reason .

Iv'e always believed it is important for the oil to reach operating temperature as quickly as possible , this reduces engine wear , reduces drag in the turbo bearings ( i can really tell this on my tomei twins that are journal bearings) , alows it to flow through the system properly and filter more efficiantly .

The head dissipates most of the engines heat , taking the hot water from here and using it to heat the oil and evenly distribute the heat around the engine is good for expansion rates , bearing clearances to name but a few reasons.

[bobbo]

Cortexx,
I agree with you that there surely isn't anyone on these forums that know or understand more than the engineers at Nissan did when developing the car.
On the other side of the coin did the Grp. A cars keep HICAS? Also I'm a big fan of the KISS method of doing things. Over complicating things makes trouble shooting and maintenance more difficult and costly as well as reliability may suffer.
I also agree that oil temps should be at 75 degrees or higher for proper operation. For example I've heard that high rpms on a cold engine can lead to valve spring failure amongst other problems.
On some of the engines i work on one of the permissives for operation is to be at 55 degrees or higher.
Thanks for the input, I appreciate it.

[nimblestix]

Ive deleted my OEM oil/water cooler, fitted an rb20 oil filter pedestal, and a trust cooler kit. My oil temps are consistently around 80°c-90°c when I'm cruising around the city.

Much easier to work on anything under the plenum, looks cleaner, and appears to operate just as efficient, plus as a little bonus oil changes became a little easier to reach the filter.

I previously had a grex filter relocation/cooler kit, but I didn't like the idea of the filter draining back every time I shut off the car, this is a big reason that I decided to try something else, which seems to be working fine.
Just my .02¢

Cheers.

[bobbo]

It's always good to get the input of others however I'm not concerned with temps while "cruising around the city" as no additional cooling should be required. It's under track conditions I'm concerned with.

[PurpleStreak]

All I have to add is that the N1 vehicles do not have this oil/water exchanger and only use an air/air oil cooler.

[bobbo]

Very interesting and thanks for posting that. It certainly gives me more to consider.

[Skym]

There seems to be more reason to leave it there than remove it . In my opinion there are alot of things on these cars that people rip out without giving it much thought . HICAS is a prime example. I'll never remove mine, and if it has a problem then ill fix it not junk it . Nissans design engineers built this car the way they did for a reason .

They designed the stock suspension setup to be stable in a straight line, but had understeer when on 90 degree + corners and didn't want to upset that straight line stability, so only needed to correct understeer when cornering hence HICAS was created (they show this understeer problem in catalogue, with and without HICAS).

Also I found this out after removing HICAS, as noticed understeer on 90 degree + corners (turning at light's, etc) with stock suspension setup. If look at swaybars on R32 GTS-T, the front swaybar is bigger than rear swaybar thus bigger front swaybar = rear wheels get more grip than front hence understeer when cornering (car doesn't want to turn in). Changing swaybars solves the problem. There are other ways to solve this turn in understeer as well, castor arm length, ride height, just to name a few.

A GTR is a bit more tricky, as have to take into account 4wd that creates understeer, so have to counteract that with oversteer with suspension setup (swaybars). It's a combination of suspension, 4wd settings that makes it work.

Iv'e always believed it is important for the oil to reach operating temperature as quickly as possible , this reduces engine wear , reduces drag in the turbo bearings ( i can really tell this on my tomei twins that are journal bearings) , alows it to flow through the system properly and filter more efficiantly .

The head dissipates most of the engines heat , taking the hot water from here and using it to heat the oil and evenly distribute the heat around the engine is good for expansion rates , bearing clearances to name but a few reasons.

Heat exchanger is designed to help get oil up to temp in cold climates (snow, etc). In hot climates or on racetrack it's not needed and actually can cause high oil, coolant temps.

[bobbo]

Heat exchanger is designed to help get oil up to temp in cold climates (snow, etc). In hot climates or on racetrack it's not needed and actually can cause high oil, coolant temps.

This supports my original thoughts.
Skym, I tend to agree with your opinions and generally believe that your comments are based on experience or from documentation from a noteworthy source. Which would it be in this case?
Thanks for chiming in.

[Skym]

This supports my original thoughts.
Skym, I tend to agree with your opinions and generally believe that your comments are based on experience or from documentation from a noteworthy source. Which would it be in this case?
Thanks for chiming in.

You're welcome. Both experience with overheating, running a heat exchanger setup and learnt from old school pro's who mentioned to configure it a certain way and it worked (runs alot cooler).

After learning off the pro's, I investigated it more (as you would) and it's common knowledge with auto transmissions that use heat exchangers in bottom of radiators when car is used in cold environments and rules you follow with heat exchangers when used for performance applications (dragracing, etc) or hot environments. It applies to oil to coolant heat exchangers.

A oil to coolant heat exchanger is designed to raise oil temps quickly in cold environments and make oil temps stay within a certain temp range (close to operating temp for oil) without oil overheating. When you modify a engine with basic breathing mods, boost level rises, cylinders run cleaner thus allow more oxygen into cylinders and engine runs leaner thus get higher cylinder temps (proven by having to change heat range with spark plugs), engine runs hotter.

That heat is transferred to the coolant, oil and thus goes outside what the heat exchanger setup (radiator size plays a role in removing this heat) was designed to handle with heat. Engines have 2x cooling systems (coolant and oil) and they should be separated to run properly. If you separated the oil from coolant, you'll probably find out that the coolant temps drop and don't have to change radiator size. Same result with oil temps when oil cooler is sized correctly.

Also I was told that Mazda has run a similar heat exchanger setup (multiple heat exchangers on engine) as well for oil, etc in cold climates, so it's nothing new that car manufacturers use heat exchangers in cold environments with auto transmission, engine oil, etc. So try researching Mazda engines, heat exchangers and you'll probably find alot of info on the subject.