DIY Oil cooler setup?

[Spartarus]

Originally Posted by DAEMANO

About the area behind the fog light bezel.

I prefer that area too so that the hot oil cooler doesn't interfere with a FMIC and is less susceptible to damage from impacts to the plastic tray or debris coming straight in. The question that has been asked a couple times (a few by @CSG_Mike ) is in regards to that being a relatively low pressure area, so where will the hot air being generated by the oil cooler be vented out to? Would it vent back up into the engine bay (no bueno), or somehow underneath the car or perhaps even someplace else?

I really like the idea of a setup like the P&L oil cooler kit that uses a thermostatically switched Setrab FanPack-like radiator to either continuously push air through the front or pull hot air off the back of the radiator (instead of airflow being speed dependent).

Few things. First, I left space behind mine for a fanpack, as I like the concept, but I didn't buy it right away because I wanted to evaluate the need. Cool idea, but there seems to be no need. My oil always heats to T-stat equilibrium and holds there. 181 deg F is where it wants to live.

If you don't have sufficient speed to cool oil, you probably aren't making enough power to heat up the oil. I will note that this may change if you put it behind the fogs, but I doubt it. I'll note that mine is placed so that the radiator fans pull air across it, but it stabilizes at the same temp regardless of whether the radiator fans are on. (That's the thermostat doing its job). If the operating temperature stabilizes at or below thermostat full-open, adding more cooling capacity will just close the thermostat further: you aren't going to change or lower equilibrium temperature without changing the thermostat. The only time you need to add cooling capacity is if temperature in the desired operating state exceeds equilibrium temp.

As far as where the heat goes, it's not incredibly important. It's just hot air, it'll find its way out. Plenty of real world proven kits use the area with no special means of extraction. Not many of us are engineers, so concepts can be posited and argued all day, but results obtained under real world conditions is all that really matters.

Even if it's going into the engine bay, excess heat in the bay from an oil cooler core is negligible, here's why: You're already introducing all the hot air from 3 radiators into the bay anyway (Radiator, AC condenser, Intercooler) That's a lot of hot air. All that air moves through the bay and carries radiant heat away with it. Hotter air carries away less heat, but it's still carrying heat away, as the air will be colder than the radiant components in the bay. As long as you're not adding another source of radiant heat in the bay itself, it's negligible. Your intercooler contributes WAY more to that problem. The best thing you can do for engine bay heat is venting the bay better, and ducting all the radiator airflow around/out of the bay separately a'la C7 Corvette.

[Calum]

Why do most of these kits put the cooler on the far side of the car from the plate? I keep thinking it would be safer to have shorter lines and put the cooler on the drivers side but I haven't had my front bumper off.

[DAEMANO]

Originally Posted by Calum

Why do most of these kits put the cooler on the far side of the car from the plate? I keep thinking it would be safer to have shorter lines and put the cooler on the drivers side but I haven't had my front bumper off.

The giant windshield washer fluid reservoir is on the driver's side.

[go_a_way1]

I am looking at building my own oil cooler, but I can’t seem to find athermostatic sandwich plate with a 3rd port for my oil temp sensor and I don’tknow if I should stack sandwich plates? Anyone know of one?

[DAEMANO]

Originally Posted by Spartarus

Few things. First, I left space behind mine for a fanpack, as I like the concept, but I didn't buy it right away because I wanted to evaluate the need. Cool idea, but there seems to be no need. My oil always heats to T-stat equilibrium and holds there. 181 deg F is where it wants to live.

What radiator were you running again? Was it a Setrab 6 series or another?

Glad to hear that there is enough room behind the cooler to place a fan back there in a "pull" configuration if need be.

If you don't have sufficient speed to cool oil, you probably aren't making enough power to heat up the oil.

Not so sure about this. Willow springs and Auto Club Speedway out here in California can easily be above 105 F in the shade and 120 F on the track. With ambient temps that high pushing crazy amounts of heat into the oil can happen while simply warming up.

If the operating temperature stabilizes at or below thermostat full-open, adding more cooling capacity will just close the thermostat further: you aren't going to change or lower equilibrium temperature without changing the thermostat. The only time you need to add cooling capacity is if temperature in the desired operating state exceeds equilibrium temp.

Out here, running too cool is rarely an issue outside of starting the car, but I can see how in a place like NY, it might be.

As far as where the heat goes, it's not incredibly important. It's just hot air, it'll find its way out. Plenty of real world proven kits use the area with no special means of extraction. Not many of us are engineers, so concepts can be posited and argued all day, but results obtained under real world conditions is all that really matters.

Even if it's going into the engine bay, excess heat in the bay from an oil cooler core is negligible, here's why: You're already introducing all the hot air from 3 radiators into the bay anyway (Radiator, AC condenser, Intercooler) That's a lot of hot air. All that air moves through the bay and carries radiant heat away with it. Hotter air carries away less heat, but it's still carrying heat away, as the air will be colder than the radiant components in the bay. As long as you're not adding another source of radiant heat in the bay itself, it's negligible. Your intercooler contributes WAY more to that problem. The best thing you can do for engine bay heat is venting the bay better, and ducting all the radiator airflow around/out of the bay separately a'la C7 Corvette.

Not so sure about the theory that where the heat gets dumped into is unimportant. A good example is the radiant heat from the exhaust header being wrapped around the oil pan heating that up. Still, agreed that a vented hood is a very good idea to round out one's cooling approach.

[Ultramaroon]

Originally Posted by Spartarus

My oil always heats to T-stat equilibrium and holds there. 181 deg F is where it wants to live.

I will ask here because I have the lazy. What exactly is the optimum oil temp? Folks cite the necessity to go above water boiling temp but I'm not sure that's absolutely necessary. The crank case is a little <1 atm, vapor pressure, Dalton's law, blah blah...

[Hyper4mance2k]

Originally Posted by DAEMANO

The giant windshield washer fluid reservoir is on the driver's side.

more pictures of that DC2ITR!!

[Spartarus]

Originally Posted by DAEMANO

The giant windshield washer fluid reservoir is on the driver's side.

Beat me to it. I considered welding up a smaller tank and mounting it on that side. There is an off-the-shelf small washer tank that can accommodate this solution, but I saved that area for turbo intake, better!

http://www.ptuning.com/subdir/itemde...&ModelDesc=FRS

That's the washer tank if anyone is interested

Originally Posted by DAEMANO

What radiator were you running again? Was it a Setrab 6 series or another?

Not so sure about this. Willow springs and Auto Club Speedway out here in California can easily be above 105 F in the shade and 120 F on the track.
...
Out here, running too cool is rarely an issue outside of starting the car, but I can see how in a place like NY, it might be.
...
Not so sure about the theory that where the heat gets dumped into is unimportant. A good example is the radiant heat from the exhaust header being wrapped around the oil pan heating that up. Still, agreed that a vented hood is a very good idea to round out one's cooling approach.

Ok 3-part answer,

Core is Earl's temp-a-cure 34-row narrow core. 10.5" body height but only 5.125" between the fitting centers.

Yes sir, It's NY and the hottest I've seen all year is 90. That and I was in Alaska before NY. Higher OAT just means a lower temp differential between the oil and air, necessitating more cooling capacity, but higher ambient temp will not affect the equilibrium temperature. It may drive up your stable temps, but that only means you're operating above the thermostat equilibrium temperature, and your cooling is being limited/regulated by the limit capacity of the system, and not the thermostat. A properly constructed system will always be regulated by the thermostat, not the limit capacity. That's the point of a thermostat.

On the radiant heat example, the your example is totally different than mine. It's not where heat is being dumped, it's air. I said that dumping hot air is negligible and not detrimental, and adding sources of radiant heat is detrimental. Hot radiator air is warmer than ambient, but still colder than the components it's passing across, therefore it's still serving to cool the components in the bay, just less so. It is still a net subtraction of heat. Adding sources of radiant heat inside the bay add heat in the bay that must be removed via cooling airflow. This is a net addition of heat without a corresponding addition in cooling. That's a brief explanation, but I can support the theory with more facts and data if you don't buy it. It isn't really a theory, it's physics, and it's a fact.

Originally Posted by Ultramaroon

I will ask here because I have the lazy. What exactly is the optimum oil temp? Folks cite the necessity to go above water boiling temp but I'm not sure that's absolutely necessary. The crank case is a little <1 atm, vapor pressure, Dalton's law, blah blah...

Fair question. The answer is there isn't one answer to that. Depends on lots of variables. Optimum for me is cold enough to maintain necessary pressure, but hot enough to evaporate water. You are correct; the boiling temp argument is based on a fundamental misunderstanding of physics. Boiling =/= Evaporation. Water will always evaporate in air that is less than 100% humidity. That's why puddles dry up. Adding energy to water accelerates the rate at which it evaporates. The longer you run the engine, the more water leaves, regardless of oil temp. As long as you're exceeding the rate of condensation in the crank case, which you always are while the car is running. I keep the temp low because this car has massive issues with low oil pressure spinning bearings, and I'm turbocharged. Oh, and I haven't spun a bearing.

The Dalton's law argument is a rare one, I haven't heard that one often. Fact is, the crankcase pressure varies, especially when boosted. Enthalpy of vaporization controls the rate of evaporation. Basically what it boils down to (lol), is pick some objectives that make sense and knock yourself out.

[zeal86]

Originally Posted by Ultramaroon

I will ask here because I have the lazy. What exactly is the optimum oil temp? Folks cite the necessity to go above water boiling temp but I'm not sure that's absolutely necessary. The crank case is a little <1 atm, vapor pressure, Dalton's law, blah blah...

+1

This topic came up in another thread...would love to hear more insight on this as well.

I have a Mishimoto oil cooler installed... I've noticed coolant temps of 190-194F (Mishimoto performance radiator) and oil temps of 183-190F (Eneos 0w-20). I reach these temps in @20 mins of normal driving... normal driving meaning city driving, no more than 50 mph. Temperatures here in Texas have ranged from 97 to 101 degrees in recent weeks.

I have not noticed my oil temps go above my coolant temps... not that it hasn't happened. I use a p3cars vent gauge to read my temps.

Btw, my 86 is naturally aspirated.

projekt zeal86 build

[zeal86]

I did a smaller windshield washer reservoir mod... if you are interested here is the link:

Windshield Washer Reservoir Mod
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projekt zeal86 build

[DAEMANO]

Originally Posted by Spartarus

Beat me to it. I considered welding up a smaller tank and mounting it on that side. There is an off-the-shelf small washer tank that can accommodate this solution, but I saved that area for turbo intake, better!

http://www.ptuning.com/subdir/itemde...&ModelDesc=FRS

That's the washer tank if anyone is interested

Thanks for taking the time to explain your position. A couple of questions. The P-Tuning washer tank looks tiny (whichi is GREAT). Do you think the space made by installing it would leave enough room to install the Earl's radiator you noted below?

Core is Earl's temp-a-cure 34-row narrow core. 10.5" body height but only 5.125" between the fitting centers.

Assuming this one (or its' silver variant)...
http://www.jegs.com/i/Earls/361/2340...ductId=1675460

Yes sir, It's NY and the hottest I've seen all year is 90. That and I was in Alaska before NY. Higher OAT just means a lower temp differential between the oil and air, necessitating more cooling capacity, but higher ambient temp will not affect the equilibrium temperature. It may drive up your stable temps, but that only means you're operating above the thermostat equilibrium temperature, and your cooling is being limited/regulated by the limit capacity of the system, and not the thermostat. A properly constructed system will always be regulated by the thermostat, not the limit capacity. That's the point of a thermostat.

On the radiant heat example, the your example is totally different than mine. It's not where heat is being dumped, it's air. I said that dumping hot air is negligible and not detrimental, and adding sources of radiant heat is detrimental. Hot radiator air is warmer than ambient, but still colder than the components it's passing across, therefore it's still serving to cool the components in the bay, just less so. It is still a net subtraction of heat. Adding sources of radiant heat inside the bay add heat in the bay that must be removed via cooling airflow. This is a net addition of heat without a corresponding addition in cooling.

So essentially your meaning is that subtraction of heat whether the heat is being "moved" from OEM oil system/engine to an aftermarket cooler located someplace else in the bay is still a net gain. Correct?

[Spartarus]

Originally Posted by DAEMANO

So essentially your meaning is that subtraction of heat whether the heat is being "moved" from OEM oil system/engine to an aftermarket cooler located someplace else in the bay is still a net gain. Correct?

It's the black one, and what I meant is, a fixed amount of energy will be transferred from the hot oil to the ambient air based on the temperature differential and cooler surface area. That warmer air will pass into the bay, but it will be cooler than the components in the bay (especially the sources of radiant heat in the bay), so it will continue to warm up as it cools the components in the engine bay, eventually leaving the car much warmer than it was when it came in, and carrying away energy with it.

For the sake of argument, even if the bay was somehow colder than the air coming off the oil cooler core, which it isn't, the air will not find equivalent surface area to transfer all the energy back into the components. As I said, the air is still colder than the surrounding components, especially once they're heat soaked, so that's a moot point. It just helps to illustrate what I'm saying.

[DAEMANO]

Originally Posted by Spartarus

It's the black one, and what I meant is, a fixed amount of energy will be transferred from the hot oil to the ambient air based on the temperature differential and cooler surface area. That warmer air will pass into the bay, but it will be cooler than the components in the bay, so it will continue to warm up as it cool the engine bay, eventually leaving the car much warmer than it was when it came in, and carrying away energy with it.

For the sake of argument, even if the bay was somehow colder than the air coming off the heater, which it isn't, the air will not find equivalent surface area to transfer all the energy back into the components. As I said, the air is still colder than the surrounding components, especially once they're heat soaked, so that's a moot point. It just helps to illustrate what I'm saying.

Ok I think I got your meaning. Thanks!

[Ultramaroon]

Originally Posted by Spartarus

The Dalton's law argument is a rare one, I haven't heard that one often. Fact is, the crankcase pressure varies, especially when boosted. Enthalpy of vaporization controls the rate of evaporation. Basically what it Boyle's down to (lol), is pick some objectives that make sense and knock yourself out.

You confirm my understanding of the application. Thanks.

I wasn't really clear. I cited Dalton's law in support of evaporation rate being independent of concentration of other gases. Kind of a dumb point but, meh, you kind of know where I was going, right?

oh, and fify.