How well do our oil coolers, cool.
 

Im just wondering how well they work.

I was thinking, a lot of air must go around the cooler since its so small and there is really no gaurd around it to keep the air infront of it instead of going above or around it. So I wonder if I pay the guy near me to weld on some 1/16" aluminum to the sides of the cooler, and have them angled outward a little to help direct the air flow into and through the cooler?

I was also thinking, with an electric fan turning on or off according to coolant temp and not oil temp (which I wouldn't have the rad fan do anyways), the oil cooler must be getting pretty hot considering the air flow through it must be very minimal?

Any thoughts on this?

I've been wondering about this too. Would putting 2 small high cfm fans on the oil cooler be benificial in anyway? If so, why?

I've even seen people put 2 oil coolers. Is it worth it? Because its really not hard to do.

if you are worried about air going around it why dont you make up some ducting

The first question would be, are you having high oil temp problems?

Setting the fans to turn on\off with coolant temps, means that they will be ON at all times (after the initial warm up period)...

This is the question I have in my head, I don't know if im having oil temp issues. I don't exactly know what to look for if the oil is overheating.

If you were to have fans on the oil cooler, obveously you would use a oil temp switch or sensor and use the Simple Voltage Switch that I hope to get soon for the coolant fan.

While idling, the engine temp heats up and the e-fan eventually turns on and off. but while sitting still there is NO air flow through the oil cooler so how hot is the oil actually getting. This might be another CON with e-fans.

This is what im thinking of doing.

I just wanted to hear from people with oil temp gauges, to tell me what there oil temp is like.

the oil coolers on our cars seem to be vary efficient, all that metal soking up the heat produced in the oil. as long as you have good oil pressure when not moving the oil cooler should function fine. when moving there is a lot of air flow going through the front of your car, that huge fan shroud creates a big ventury and pulls air across the radiator and oil cooler. i seemed to have better cooling when i got rid of my air conditioning, having that air gap bettween the oilcooler and rad. helped alot. i still have hot conditions when runing hard up hills, have so little belt contact in the water pump doesnt help, need to get that yo-ho belt from pineapple racing.

Do you have a FMIC or any other device that WILL block the air?

My suggestion before you do anything, is to get an oil temp gauge. Oil temps were never a problem on my NA or stock mount intecooler days...


Well I was going by what you originally posted:
If this is your plan, then the oil cooler fans WILL be on at all times...

NEVER on my NA or SMIC turbo days; and yes with a FMIC.

nah nah, I don't mean putting fans on the cooler and have them activate by coolant temp. That is just plain dump. If I were to put fans on the cooler then I would have the fans activated by oil temp. The fans would not be on at all times.

Nope, I have a N/A, but air rushing in wont just easily go through the cooler. A lot of it will go AROUND the cooler. Now while you are NOT driving, im wondering how hot the temps would get since there is ZERO airflow through the cooler. I may or may not have oil temp problems, but im trying to think of ways to make it work more efficiant since im seeing how it may not be working to its full potential.

KNONFS, do you have a oil temp gauge?

Thats a problems, that metal socking up the heat then has to be disipated through the fins. Only way that will happen is with sufficiant air flow. Think of how the radiator works. If you don't have any fan on, at idle, you will eventually cook the motor.

The flow of oil will not make the cooler work any better. You simply heating the cooler up that has no air flowing through it at idle or has hopfully enough air flowing through it while driving.

I have a e-fan without a shroud. I am going to make one though. It would probubly work better if I had the cooler ducked straight to the engine rad, since I don't have not A/C, there is a gap there. So if I build a shroud that goes from top to the bottom of the rad and have the oil cooler ducted to the rad and sealed off with some slit rubber vacuum line, I should get some air flow through the cooler, and if I have a shround on the front to direct air into the cooler and keep it instead of having it go around, that should also help.

With the gap between the rad and oil cooler, the fan would simply pull air from around the the oil cooler and very little through it. Air takes the path of least resistance.

With the A/C condenser in place, I forget how close all three heat exchangers were together, but im sure the A/c condenser with the full shround helped to duct some of the air flow through the oil cooler.

As I said, never had an issue with oil temps before the FMIC. I see were you are coming from, but if is not broken why fix it?


Yes, 185F was the max, before the FMIC; I could actually see the oil cooler thermostat opening and closing.



I thought about moving the efan to the other side of the radiator (I am not running the A/C), and make it a pusher rather than a puller. That way the efan will be closer to the oil cooler, sort of pulling air from the oil cooler, and pushing it through the radiator. That's an idea, that probably won't work without some ducting, another idea is to move the oil cooler closer to the radiator, and maximize the radiator's efan pulling air.

I have considered small ATV fans for the oil cooler, but for now I have to finish other things before I can play with that theory...

Ya I suppose it wouldn't be to hard to make some brackets to move the cooler closer to the rad. I have heard and I think this way as well, unles proven wrong, that the e-fan is les efficient at pushing air then it is pulling air.

If you engine is not broken, why make it perform better? :) Same goes for the heat exchangers.

fyi, the skyline guys use our oil cooler as an upgrade

Its not the same, as the oil cooler has an internal thermostat; you can move the oil cooler to the front of the bumper cover opening, the thermostat will always regulate the temp.

Unless you are looking into running colder oil temps, I don't see what good is going to do you; besides cooler oil (under 185F) is not a good thing either.

The bypass valve will regulate the flow of oil to the cooler depending on the oil temp. If the cooler is not working very efficient, the oil temps could get higher and the bypass valve will have no positive effect besides letting the oil pass through the cooler. If there is no air flow or very little of it, we may have an issue. Im not looking to run cooler, just want to make sure if the setup was working good on other FCs as well, especially after or during hard runs.

But with that said, I do like hearing you have or had basically the same setup; no a/c, no FMIC; and had no issues. I will get a Oil Temp Gauge so i know. I recently switched to AMSOIL which performs better then any other oils under high heat so I should be ok there IF the temps are not low enough.

The bypass valve in the oil cooler im sure is primarily there for emmisions so the engine heats up quicker. Once the engine is heated, im sure that bypass valve in the cooler never opens since its rated to start closing at 140-145*F. Now having that said......
What was the lowest oil temp you have seen? Does it really get that low? I can't see the engine oil getting down to 145 while operating since the engine coolant itself runs at 185+, even without a thermostat, I can't see the coolant temps dropping to 145 or below 160, but I don't know this for sure, soon I will though, I think my t-stat is junk.

I Like the conversation :)

I'm pretty sure thats incorrect. The bypass valve you are thinking of is the thermopellet, and it doesn't push oil to the oil cooler... it just releases it back into the pan/front cover area. And for most of us with the thermopellet replacements, the oil cooler would be cooling 100% of the time. Oil has an optimum operating temperature, so this wouldn't be ideal.

I know nothing of how the oil cooler works, but what I'm getting from KNONFS the bypass valve he is talking about is INSIDE the oil cooler and activates at 185F, starting the flow through the cooler finned portion, when its off, it just bypasses the cooling fins and pipes it back to the engine...

I like the cooling fan idea, but only as an additional measure of protection from super-heated oil during hard runs in autoX or what not, but... it might be overkill, expecially for an NA that doesn't have any turbo's to cool/lube.

The bypass valve I am talking about is in the oil cooler. Its called a bypass valve and not a thermostat. It only regulates the flow of oil to the inside of the cooler. After your engine oil reaches 140-145*F, the bypass valve closes and the oil passes through the cooler. I know it doesn't push the oil. Thats what the oil pump does. the one in the cooler is open below 145*F so the oil bypass's the cooler.

I can see where you got confused. When I said it regulates oil TO the cooler. I meant to the inside of the cooler. Where the oil actually has the abuility to be cooled.

The thermopellet your talking about in the center of the main pulley basically does the same thing. I havn't read up on exactly how the one in the pulley works since I don't have it any more. Maybe I will read up on that one just for shits.

Ya I have been doing some searching and it seems normal oil temps are around 180*F but can reach 200*F. So the bypass valve would always stay closed while the engine is running. I wouldn't put fans on the cooler but instead would make it work with the fan that is on the rad and try to direct airflow through it better to make it more efficient.

I understood you correctly.. I just still think you are wrong. Which is okay. Wouldn't be the first time I've been proven wrong.... won't be the last.

I was thinking and it would have been even better to have said, regulates the flow of oil through the cooler

My bad.

We still seeing differently?

I feel the stock cooler works just fine the way it is. My oil temps stay at about 150-160 and whhile pushing it hard up a hill will climb up to about 190. Moves porportional to water temp. Also there is no load on the engines while the car isn't moving and the stock fan moves enough air to keep temps low. I don't get this whole talk about fans, you would only need more cooling when the engine is working overtime so the airflow over the cooler is already greater from 60mph then a fan can provide. Kinda like your rad fan is freewheeling when driving down the highway.

My .02 cents.You don't want the Oil to be TOO cool.Oil is Thinner when it is Hot.That is GOOD.it is able to do it's Job of Lubricating the Parts it needs to get at.The Oil System also acts like a Cooling system too.Since the oil is getting Circulated Through the Cooler to Bring the Temp Down.The Oil cooler on an N/a is a Fair size too,so it is capable of Doing it's Job.In my Opinion Putting On a Fan is just Dead weight,and really,If you have the Underbelly Tray on,then the Cooler is getting sufficient Air to it.(the Engine temps will be Higher without the Belly tray,so it is Wise to keep it ON.)

I dunno if I'd call the FC oil cooler "so small", since it's about the largest OEM oil cooler you'll find. ;) I see the logic of your thinking, but unless you’re actually having an oil temp problem, all you'll be doing is using air that would otherwise go through the radiator to unnecessarily cool the oil. So no real gains but possible losses.

The coolant and oil temps do tend to follow each other somewhat. I once (unknowingly) sucked a plastic bag into the front of my car, which managed to completely cover the oil cooler. I have no oil temp gauge, but instead noticed the water temp would rise alarmingly when any load was put on the engine.

There's also barely any load on the engine, so it's generating very little heat. If this really was an issue, the factory would already have provided a solution. Have you every heard of oil overheating while idling?

You're trying to solve a problem that most likely doesn't exist. If you successfully improve the oil cooler's efficiency, you'll make the oil cooler, and that's not necessarily a good thing. Cooler oil that's too thick can be just as bad as hot oil that's too thin.

True, but this just isn't an issue for the reasons I explained. With the car moving, enough air is being forced through the oil cooler to sufficiently cool the oil.

Well it's not just for emissions, as there are other benefits to heating up the engine quicker. But you're right that flow through the oil cooler is not regulated to control temp like the coolant flow is. The oil cooler is essentially at full flow from the moment to the oil passes ~145degF to when the engine is switched off and the oil is allowed to cool below that. I doubt anything you do to the oil cooler will get the oil temp that low, but you still don't necessarily want to be lowering oil temps.

The oil fed into the eccentric shaft does two things: it lubricates the rotor bearings and it's squirted onto the inside of the rotors for cooling (this is the main reason for the oil cooler). When the engine is cold, a bypass port at the front of the shaft is open, which reduces oil pressure in the shaft and prevents the oil squirters from working. This helps the engine warm up faster. When the oil heats up the thermal pellet expands and blocks the bypass ports, making the squirters functional. Contrary to popular belief, this doesn't cause damage to the bearings, as there's still enough pressure to protect them during the warm-up when you're supposed to be going easy on the motor.

Only at low speed, and only if you can actually find suitable fans. Small-diameter, high-flow, weatherproof, 12V fans are not exactly common...

It would only be worth it if you actually had an oil temp problem, and you'd exhausted all other ways of improving the oil cooler's performance, like proper airflow management. I'm pretty sure you'll find that it's not as simple or easy as you think. It's not like there's a lot of room in there.

See above, oil temp is not regulated like coolant temp.

He's right. You're confusing two separate systems, although both are there for the same reason (faster warm-up).

Your right ,the factory had an a/c condenser on the car and a shroud with a fan that continuously pulls air, not much if the clutch is disengagued but still pulls air. This is not the case with my car at this point. No Mechanical fan, no shroud, no a/c condenser, which I can't decided completly if the condenser between the rad and oil cooler would help direct the pulled air through the oil cooler or not.

No I havn't, but I have seen worried people with oil temps hitting 200+ while driving. Not sure if thats overheating or not. While at idle, your engine can still cook. Your right it doesn't produce a lot of heat, but it will cook its self if there is no airflow through the rad. So it must be the same about the oil correct?

Well thats good to know. I also wonder how much that plastic bag effected the airflow through the bottom portion of the radiator.

Probubly doesn't, but why not make it work more efficient?

I thought I edited that portion you quoted cause I relieazed I said it wrong since it works opposite of what the coolan thermostat does, actually it was the 3rd paragraph I edited, opps.. Anyways, ya im not trying to get the temps that low at all. I just don't see, on my car, how its being very efficient so can only think that it might be getting a little hot. I have to get a temp gauge for this though.

Thank you for clearing that up. I understand that better now. :)

Thats the problem, I don't have the stock clutch fan or shround, I have an electric fan without one. Ya in the beginning I wasn't trying to say I was going ot hook my fan up to the cooler, basically saying, while my e-fan is off at idle, engine coolant heats up, so does the oil cooler, fan turns on, cools the coolant, but not pulling any airflow through the cooler. Maybe a tiny tiny bit but doubt its enough.

This is where you will get different opinions. If the oil is to thin, the oil won't be able to stick to the parts and will easily move off anything its trying to lubricate and can easily get pushed around. Using a heavier weight oil, the oil is able to lubricate better since it can stick to the parts longer and not get thrown off as easily. This is also just my opinion, for fact, well, we will have to wait for someone to cleaer that up.

The paragraph of mine he read did sound like I was talking about the bypass valve in the e-shaft, but I was actually talking about the one in the cooler. His confusion is my fault.

I also feel the need to point out that this is about 1000th time this has been covered in the last 12 months. A search for "aftermarket oil cooler", "oil cooler upgrade" and variations would have turned up the many past threads....

Considering I was not thinking of putting in an aftermarket oil cooler, I had no reason to search for that, same with, oil cooler upgrade. However, I did search for oil temp and found that everyone was staying at around 180 or so for oil temp, BUT that is with stock cooling equipment.

This thread could bring up better points to consider when thinking about oil cooler cooling or swapping to an electric fan or removing the a/c condensor.

So it doesn't close if the oil temp fall under 145F?

I forgot to mention, all of my readings have been with a flex a lite black magic fan; i ditched the stock fan a loooong time ago :)

I'm curious: Is the A/C condenser supposed to have a piece of metal on the bottom it that partially blocks the back side of the oil cooler, and part of the front of the condenser?

Because the one I put on my car from the junkyard does...and it looked like it was supposed to be there, but it didn't make much sense.

OTOH I haven't noticed any temperature or A/C problems even with it on there...

No, it wouldn't help at all.

While this is a logical assumption, it must be incorrect otherwise it would be a very common and well-know problem. There are plenty of people with electric fans and oil temp gauges, but I've never heard any of these people talk about idle oil temp being an issue.

Because if your temps are okay now, even at full load, then improving the oil cooler's efficiency will lower the oil temp, which isn't necessarily a good thing.

Yes it does, but that doesn't happen during driving, it only happens once the engine's been turned off and left to cool. I did say that...

I am confused, I don't get how it *only* closes when the engine is off. Does it works by temp and pressure?

I don't know the exact oil temp, but during winter time; even with a FMIC, the oil temps are considerably lower

It works by temp only. Considering while your engine is running and at operating temps, your oil temp should not get to 145*F, the bypass valve will be closed ABOVE 145*F. When we say closed, we mean that it closed the bypass hole for the oil which if opened, would allow the oil to flow directly through the cooler end tank without flowing through the cooler its self. When the engine is off, the oil will cool to and below 145*F and will open the bypass hole which you does nothing while the engine is off, but when you start the car up next time, if the oil in the engine is cool enough, the oil will flow right through the bypass hole untill it heats up to 145 and then the hole closes off and the oil flows through the cooler.

I suppose, but I havn't seen a whole lot of members with oil temp gauges either. Like I said before, I may not have an issue with the oil temp at all, I just couldn't see how it could be working to its full potential.

I don't think the oil will get to a temp that we have to worry about if we made it more efficeint.

Im still undecided.

hmm, could you take a picture?

Which has a shroud :) I am probubly thinking to hard on this subject.

I understand what happen when the valve closes; the question is when and how, since NZconvertible said that "it only happens once the engine's been turned off and left to cool"

As I stated, oil temps are are way cooler during winter time, unfortunately; I never recorded their readings.

Yes it does, but it only covers 3/4 of the radiator.

The oil temp doesn't cool enough to open the bypass until the engine stops running. How could it? It's circulating through an engine who's coolant never drops below 180degF.

How could something behind the oil cooler guide air that's in front of it? That makes no sense.

No no no, the air that is being pulled, the way im thinking of it is like 2 straws, suck in one and hold the 2nd straw an inch away from the first straws end and put your finger over the 2nd straw, you will feel no suction, now put the straws together or atleast so they are tuching, now the air you are sucking through the first straw is also going through the second straw. I don't know what you would call this, guiding vacuum?

So using the a/c condensor, which I forget exactly how close it was to each exchanger but I would think that it could help guide this.......vacuum? Again don't know what to call it, through the oil cooler, or somthing like that....

Well, on normal spring\fall days, the oil temp does match the coolant temp; however on summer\winter time thats not really the case. For example on a hot summer day, the oil temp will match the coolant temp, and then proceeds to climb above 200F (with a FMIC). In my experience, the coolant temp does not moves from 185F (normal every day reading on the autometer gauge, E6K reads +/- 3 degrees) untill the oil temps reach 210-215F, at that point the coolant temp starts climbing slowly.

On the other hand, during winter timel the coolant temp will reach 185F fairly fast; while the oil temps take its time to rach that level, however as soon as the car starts moving, oil temps go down from its normal readings. On my case, my daily route constitues of small up and down hills. During a 20 mile trip of up and down hills, oil temps do go under 160F (I know they go lower than that, but can't ramember the exact number); while coolant temps stay at 185F.

All readings are based on Autometer's phantom electrical oil\coolant temp gauges. oil temp is measured at the oil filter, and water temp under the water thermostat.

I am not arguing with you, just trying to understand who it works, based on my experience.

You got snow stuffed on the oil cooler during the winter. There is your problem :):):)

JP

You need an oil temp gauge :lol2:

hahaha. :)

It's called making one long straw out of two short ones. As soon as there was any gap between the two straws, the air moving through the second one would drop dramatically because it's much easier for air to enter through the gap than down the second straw.

No, air simply doesn't behave like that. Besides, there is a significant gap between the A/C condensor and the oil cooler.

I'm not saying they do, I'm just saying there's no way the oil is going to get 40degF cooler than the coolant, which is the only way the oil cooler bypass could open when the engine's hot.

You wouldn't able to see if very well if I took a picture of it on the car.

It's basically just a peice of sheet metal that bolts onto the bottom 3 1/2 inches or so of the bottom of the front of the A/C condenser, and has a little lip that sort of catches on the top of the back of the oil cooler.

Exactly, this is why I mentioned the statment about the a/c condenser. Kinda lengthens the straw if you will.

Aight I couldn't remember how much of a gap there was between the 2.

Not to mention the fact there's a block off plate on the bottom of the condensor which would prevent the hot air coming off the oil cooler to be passed through the condensor.

That completly ended my opinion on that subject. So that idea is out the door. Thanks for commenting in. :)

just as a little side note here as i admit to skipping most of these posts.

I look at it this way, LOTS of people with different cars upgrade to our stock oil cooler.

if ours works so good that they upgrade to it, id figure it does a pretty good job.

and like one other poster said, colder oil isnt always the best thing, theres a sweet spot.

kevin.

I have my oil cooler mounted in front of my IC and higher, with a hole in the front bumper, and I experience the same thing you just said. During hot days my oil temps are about 15 degrees hotter while driving. Coolant always stays around 180-185, and oil temps are around 200. Cold winter days the oil coolant shoots up and stays, and oil stays super cool. Now if sitting in traffic, or with blocked airflow on hot days Im seeing maybe 210 for oil which is normal. This is with running a 60-1 which is only oil cooled. Everything this is fine at the moment, but I do want to upgrade to a batter unit. i know we have good oil coolers, but there are better setups out there.

Here's a couple of pics of the stock oil cooler, AC condensor and radiator set-up, showing the deflector behind the oil cooler. The deflector is actually mounted to the front of the AC condensor, and prevents air that's gone through the oil cooler from going through the condensor. All air that's passed through the oil cooler then goes under the condensor and through the radiator. The foam strips on the bottom of the oil cooler and radiator seal them to the undertray so air doesn't go under then instead of through. :)

Thanks NZ! :) Its been awhile since I have seen the a/c setup.