Oil Cooler question

[CJK440]

I've got a 97 Mustang Cobra, it has been modified including a supercharger (self contained oil system). These cars came from the factory with a pancake style oil to water cooler located right under the filter. Problem is the addition of an aftermarket front K-frame doesn't leave enough room for the OE cooler and a filter. Right now, I am running a regular mustang oil filter adapter without an oil cooler but think I should add one.

Other than not installing a cooler, I think I have two options. 1- Install a factory oil cooler with a remote filter kit. 2- Install an aftermarket oil to air cooler along with a remote filter. I'd rather not deal with oil hoses but either of these options require them.

My question is this, what are the pluses and minuses of air cooling and water cooling? One other thing to consider is I think my cooling system is a little taxed and I wonder if water cooling the oil might add to this. But then again in the front I have a PS cooler, air to air intercooler, A/C condenser and finally the radiator.....

 

[CATERHAM]

I doubt your cooling system is taxed.
The advantage of an oil to water system is that it regulates the oil temperature more effectively, plus allowing the oil to heat up faster.

The first thing I would install if you haven't already is an oil pressure/temperature gauge. It's unlikely you're seeing excessive oil temp's unless you track your car and at the very least you'll know.

 

[rslifkin]

Caterham is right about the benefits of oil to water compared to oil to air.

I'd personally run the factory oil to water and just relocate the filter. Also, if you can't relocate the filter, and can't fit the full FL-1A sized filter (L30001), a Purolator L14670 is the shorter version of the same filter.

 

[CJK440]

That makes sense about regulating temperature. The car is not a track car and to be honest the biggest reason that is motivating me to put a cooler on, is the factory thought it to be a good idea with a stock Cobra.

I do have a real pressure gauge and get a large pressure drop when hot. 100+ psi cold to 25psi at hot idle which is the same when the rebuilt motor was fired up.

As for the cooling issue, in the summer the coolant temp can climb to 250 (aftermarket gauge) on the highway with the A/C on. I am not sure of the cause but I am not the only one with this issue. Could be obstruction from the intercooler, who knows.

The filter issue is not length but diameter. I'm not too thrilled with oil hoses for whatever reason. Almost makes me want to notch the K-frame for clearance rather than install a remote setup.

 

[galaxy]

I don't know why you're so anti-remote filter. I run them on every single car I've ever owned and have never had a problem. If you're concerned about something happening to the hose and loosing oil, use a stainless braided hose with AN fittings. Bullet proof and looks super-cool! A way much better option that notching your subframe just to retain the stock filter.

 

[4ever4d]

Originally Posted By: galaxy
I don't know why you're so anti-remote filter. I run them on every single car I've ever owned and have never had a problem. If you're concerned about something happening to the hose and loosing oil, use a stainless braided hose with AN fittings. Bullet proof and looks super-cool! A way much better option that notching your subframe just to retain the stock filter.

+1 Notching the frame will weaken it,this could come back to bite you in the back side at some point in time,as for the high temps at highway speed a coolant additive may help,they do work i have seen them drop temps by 20 degrees on stock vehicles.Water Wetter,Purple Ice...etc i think could help,and you very well may be restricting air flow with everything stacked in front of your radiator.

 

[dwendt44]

Quote:
in the summer the coolant temp can climb to 250 (aftermarket gauge) on the highway with the A/C on.


That doesn't sound right to me. At highway cruise, the temp should be the lowest, right at the thermostat rating.
How clean is the inside of the radiator?
You might consider a 180° thermostat.

 

[Gary Allan]

I agree that the coolant temp isn't right. If you removed any panels in the alterations you performed, replace them. Routing through the radiator may have been affected.

Nothing much to do about the filter.

 

[CJK440]

Originally Posted By: dwendt44
Quote:
in the summer the coolant temp can climb to 250 (aftermarket gauge) on the highway with the A/C on.


That doesn't sound right to me. At highway cruise, the temp should be the lowest, right at the thermostat rating.
How clean is the inside of the radiator?
You might consider a 180° thermostat.


You'd think.

I have a 180 stat in there now. The car has 50k miles, I did not peek inside the rad but I'm guessing its clean. Been through a couple complex "burping" procedures, am already running Water Wetter. Fan low & high turn on speeds have not been altered to match the stat though. They have high set points. 208 low speed 228 high speed and idling in the driveway, it sits a 210 or so, but that doesn't help the highway issue.

Nothing has been removed such as air dam etc. The only thing is that big intercooler in front of the radiator. I simply think the airflow thru the rad on the SN95 (96-98) cars just sucks and the IC doesn't help. The 96 Cobras promptly had a TSB put out to modify the cooling system.

 

[CJK440]

Originally Posted By: galaxy
I don't know why you're so anti-remote filter. I run them on every single car I've ever owned and have never had a problem. If you're concerned about something happening to the hose and loosing oil, use a stainless braided hose with AN fittings. Bullet proof and looks super-cool! A way much better option that notching your subframe just to retain the stock filter.


The car is a plumbing nightmare already. Intercooler hoses, hydroboost and PS cooler lines, convoluted radiator hoses, A/C stuff etc. etc. Didn't want to add one more thing, trying to keep it simple as possible.

 

[CATERHAM]

So adding an oil cooler is not a solution, you have a radiator and/or air flow through the rad' problem and that is where you should concentrate your efforts.
As mentioned with a 180 degree t'stat, at highway speeds the coolant temp should be under 200 degrees even on the hottest days.

 

[umungus1122]

Run a bit thicker synthetic in the 40 range to deal with extra oil heat as long as it's not excessive.

 

[CATERHAM]

Originally Posted By: umungus1122
Run a bit thicker synthetic in the 40 range to deal with extra oil heat as long as it's not excessive.


That's not where the OP should be looking to make a change, he should solve the excessively high coolant temp' not try to live with it.
Having said that, we don't know what oil the OP is currently running but the hot idle oil pressure of 25 psi if fine which indicates the oil viscosity is not too light.

 

[galaxy]

Originally Posted By: umungus1122
Run a bit thicker synthetic in the 40 range to deal with extra oil heat as long as it's not excessive.


Someone correct me if I'm misspoken, but a heavier oil is not the correct answer to a (assumed) high oil temp issue anyways. An oils advertised viscosity is usually measured at 212*, and I'm willing to bet even with his high coolant temps the oil is not running that hot. A 40 weight doesn't "deal" with higher oil temps any better or different than any other weight.

 

[Gary Allan]

Originally Posted By: galaxy
Originally Posted By: umungus1122
Run a bit thicker synthetic in the 40 range to deal with extra oil heat as long as it's not excessive.


Someone correct me if I'm misspoken, but a heavier oil is not the correct answer to a (assumed) high oil temp issue anyways. An oils advertised viscosity is usually measured at 212*, and I'm willing to bet even with his high coolant temps the oil is not running that hot. A 40 weight doesn't "deal" with higher oil temps any better or different than any other weight.


No, but if one finds themselves outside the acceptable range of visc due to higher coolant temps, that would be a way to compensate.

Oil temp is somewhat tied to coolant temp. The oil is reading and creating thermal back pressure. What is outside of the control range of the thermostat MUST go somewhere. It's either (mainly) the exhaust and the oil. If you're above 195F (or whatever the thermostat set point is) there's no two ways about it, the oil is hotter too. Assuming the cooling system is of ample capacity, the oil will rise above coolant temp with more load, but will never go beyond(something like) 220F since it will create more thermal "back pressure" and more and more btu's will be seeking escape via the path of least resistance, the rad. Once you exceed the excess capacity, that will no longer be possible. As the coolant temp rises ..so does the oil's appearance in terms of an escape hatch for heat.

In most engines higher sustained oil temps just mean you age the oil quicker. That's why a SBC ..that pulls fully loaded trailers up 6-8% grades ..with the coolant temp going up (not out of control, just up) recommend a shortened drain interval NOT a higher visc oil. They've factored the visc needs with the OEM spec.

 

[CJK440]

I'm running the recommended 5w20 dino oil for now since the motor is recently rebuilt. Will be switching to full synth soon. Some people advise against any viscosity changes due to hyd lash adjuster pump up issues at high RPMs.

I realize there is an airflow issue with the car and am unsure how to fix the flow issue with all the [censored] in front. Some people had success with simply going with an aftermarket radiator, others lower the fan turn on temps to force airflow thru the rad regardless of vehicle speed. The later needs to be done regardless. This will be addressed one way or the other soon.

As for the original question, thanks for explaining the difference between air and water coolers. My goal with the cooler wasn't to lower coolant temps of course, I merely wanted to place a cooler back into service since the factory thought it was a good idea. Perhaps since its not driven hard for extended periods, I can simply get away with getting a handle on the coolant temps and letting the oil dissipate heat thru the all aluminum engine.

 

[CATERHAM]

CJK440, that's what I would do. Good luck.

 

[SteveSRT8]

despite popular opinion I recommend the much simpler flat plate oil cooler plumbed right into the filter mount adapter. A thermostat is readily available if needed. Packaging is critical on a smaller car and flat plate coolers can be small but effective.

It is FAR simpler and "Rube Goldberg"-like than the oil to water types, and it eliminates some possible failure points.

 

[Gary Allan]

oil:water coolers are much more compact. Air rads are poor conductors of heat in comparison. I think you'll exchange potential failure points.

He may be able to fit the filter with a sandwich adapter installed and the cooler removed. I'm not sure how thick his exchanger is ..and they can vary quite a bit (out of those Ford used over the years).

That said, once his coolant temp issues are solved, it becomes a non-issue.

 

[SteveSRT8]

Say all you want, I've used both and my experience is you tap into MORE places to install the water/oil type. Simply more points to fail or leak both coolant AND oil!

And putting more heat into an overtaxed stock cooling system on a high output motor is an issue to consider.

The last sandwich adapter I just put on a 6.1 Liter Chrysler product was only about 3/4 inch thick, and a solid piece of billet aluminum. Stock filter still fits easily in very confined space. Just two small armored hoses and you're already done.

The modern flat plate designs are extremely small and very efficient with excellent performance and near zero pressure drop. They generally surprise people at just how well they work when they are really small!

My favorite is a GM part and is less than 100 bucks with a nice bracket, easy to fab up whatever you need.