stock oil heat exchanger from NA8/NB effectiveness?
 

I've been getting some really bad oil heat issues on my turbo NA1.6 in the summer. While I have it in the garage for the winter I'm doing some necessary upgrades and I want to address this. I plan on getting an oil cooler and an aluminum radiator, but before I put out 500+ on a fancy track-rated oil cooling system, I'm wondering if the stock heat exchanger from an NA8/NB is sufficient in keeping temps under control on a street setup. It would be a lot easier on my hands and wallet to be able to pick up a used exchanger if its enough to do the job.

Would a turbo add too much heat for it? I don't plan on ever tracking the car, and I'm aware of the added cooling system impact, all I want is to keep the oil temps down on a hot day.

The oil cooler on the better engines is an oil warmer, not an oil cooler.

A street only miata has no use of an oil cooler.

Its an exchanger, so it does both. And I could very much use an oil cooler.

So why did you post the question if you know the answer?

Fucking dumbass kids...

What? thats not the question.

miataturbo.net be like

"stock oil heat exchanger from NA8/NB effectiveness?"

MT.net - "No, it's functionally an oil warmer."

Fucking dumbass kid - "no, it's an oil cooler."

guess ill just have to wait for a more useful person to come along

It does work both ways. If the water temp is higher, it warms the oil. If the water temp is lower, it cools the oil. So in theory, a better radiator will help cool the oil a little more by providing a higher temperature delta. The MSM also had a slightly larger water/oil heat exchanger for its higher heat load. As for being "enough" for a street car, that's really something you have to test on your own for you're version of a "street" car.

It doesnt cost too much for a second-hand one, I'm willing to give it a try if nobody else has. Ill guineepig it but everyone else will have to wait till the summer for the results.

It works fine for a street car.

Just put Deezums on ignore, he's moody and erratic. :rofl:

Thank you

on that note if somebody has a spare exchanger and filter stud lying around, lemme know

So your "street" car oil is above 280*F?
It does both, but seems more of a warmer than efficient cooler. Just look at the tiny passages.
The coolant lines are more of a PITA than the exchanger itself.

Does the oil need to be above 280 to justify wanting lower oil temperatures? I'm not allowed to be uncomfortable with the oil being under 20 psi on the highway during the summer?

Is your concern "my oil pressure is low at highway cruise during the summer" and did that get you to the statement "I've been getting some really bad oil heat issues on my turbo NA1.6 in the summer.", or have you actually been measuring oil temperature?

Can you help us understand your situation by answering the following?

* What oil brand and weight are you running?
* If you've been measuring temperature, what temperatures are you seeing, when, and for how long?

Just from a theory perspective, the coolant lines to and from the heat exchanger we're discussing are approximately 1/4" inside diameter, IIRC. There's no way those little lines are going to flow enough volume to efficiently transfer the heat away from your oil and into your coolant. You have a shit-ton of oil flowing through the heat exchanger - to strip away heat, you'd need shit-tons of water flowing through too. That is not going to happen.

Which is a long way of saying what's already been said - no, a 1.8L heat exchanger isn't going to do anything for you except add to your misery as you try and plumb it in, and add potential failure points where you made the mods to make it work.

But in the interest of helping you out - please consider answering my questions in the post above.

Thank you.
I'm using T6, not taking measurements but I have excessive degradation and lower than normal pressure in the summer, both of which are not issues during the rest of the year.
This is absolutely not a permanent solution, I do plan on getting an independent cooler, but I've decided that I'm too curious about this to not get one and see what it does. I agree that its not going to perfect, it was more just a curiosity and gathering research. I see a lot of stuff about removing it and questioning its effectiveness, but I cant find anything on purposefully adding it to a motor that never had it to begin with. I wanted to start this thread because I know I wont be the only one with this in mind. For science, if you will.
Besides, I wouldn't mind the oil warming up a little quicker on a cold day.

If you're actually degrading T6 on a street car with good change intervals, I'd say you have a problem that will only be masked by an oil cooler.

I'll let some of the more turbo-knowledgeable folks jump on that.

How are you determining "excessive degradation"?
What turbo are you running?
What engine management are you running?
How was the engine tuned?
What mileage is on the engine?

On my current build I chose not to use the factory heat exchanger because the coolant lines are a liability. Instead, I'm using the FM/Setrab cooler. I also installed the small GM temp sensor in the pan so I can log the oil temps. What I have found is that the oil comes up to temp fairly quickly. Nearly as quick as the coolant so there is not much benefit from the heat exchanger in that regard on a turbo application. The factory unit is probably engineered correctly as far as the ratio of water to oil volume since the heat transfer rate of the coolant is much higher then the oil. I would save up for an oil cooler instead of running the factory exchanger.