Extreme Heat Transmission Cooler

[MikeE024]

Case in point the Ford Ecoboost oil cooler mod. I looked it over but didn't see any data supporting it's installation other than claims of improved fuel mileage...which might have come from other mods like a tune, ceramic coating the exhaust and intake and an electric fan.

Nonetheless I pressed on. I installed the oil cooler and I installed a glowshift oil pressure and temperature sensor.

I've tracked enough data at this point to know the mod does more oil heating than cooling...I haven't removed it yet because I'm still researching whether or not that's a good thing or bad...but absolutely zero change in fuel mileage.

-Mac

I saw a GM study that showed piston wear increased as coolant temps (and oil temps) dropped.

It showed that coolant temps at 240 was better than 230, which was much better than 210, which was better than 200 and so on.

From that info, I assumed the 195 thermo stat might be a balance to get the coolant and oil temps up to reduce wear but low enough to not cause other problems like blown head gaskets, etc.

I don’t know if that’s that case, but that’s where my head is currently at on it.

All that to say maybe adding the cooler/heater helps reduce engine wear? I’m in no position to have a planted stance, but it’s something to possibly consider as you evaluate this.

As long as your coolant temps aren't over heating, I can’t think of why having the oil heat up sooner and remain a bit higher (more towards your ECTs) would be a bad thing.

 

[Rickyd]

I saw a GM study that showed piston wear increased as coolant temps (and oil temps) dropped.

My question for them would be what piston to bore clearance and piston material are they using? Oil composition probably plays a role as well.

I can think of situations where that could be true or not depending on how the motor is set up

 

[mrblaine]

Not only that, the thought that slowing the liquid flow allows it to dissipate more heat is flawed, and goes against the laws of thermodynamics that show faster flow transfers more heat. This is why “high flow” water pumps cause an engine to run cooler - they push the coolant through the radiator faster. You never see a company marketing a “low flow” water pump for a reason.

That fully ignores every single aspect of how the thermostat functions.

 

[mrblaine]

Otherwise you actually have no idea if you’ve made it better/worse/same, and you end up fighting the internet.

Or common sense. But hey, lots of folks took Jerry's word for the "awesome" fan driven Derale under the tub. He had no idea how well it did or didn't work since he didn't and wouldn't run a temp gauge, but here we are.

 

[KennethS]

I cannot recall a single thread in any auto forum over the decades where some dude removed his thermostat because his engine was running to hot thinking thats the ticket. The typical response is removing the thermo causes improper engine temps and to much flow from little dwell time in the rad causing reduced heat transfer rendering the idea worthless. So whats the truth on thermo dynamics and real world use?

I have removed the thermostat on several vehicles, including the TJ. The result was the coolant temperature stayed around 140ºF. This was all in areas with very hot summer temperatures.

The reality is the laws of thermodynamics show faster flow = greater heat transfer.

 

[KennethS]

That fully ignores every single aspect of how the thermostat functions.

I'm not following. The thermostat regulates the flow through the radiator in order to speed the initial coolant warm-up and afterwards maintain a minimum operating temperature.

 

[mrblaine]

I'm not following. The thermostat regulates the flow through the radiator in order to maintain a minimum operating temperature.

That is correct and if the flow increase from a "higher volume" through the radiator increases cooling, then the thermostat closes in response to restrict flow. The dwell time in the heat exhanger is controlled by the thermostat. If you had the materials and the lake nearby with a consistent 40 degree endless supply of water and a 1000 gallon per minute pump hooked up to the engine and no radiator, the flow would be regulated to the temp rating of the thermostat even without a radiator.

 

[astjp2]

I'm not following. The thermostat regulates the flow through the radiator in order to speed the initial coolant warm-up and afterwards maintain a minimum operating temperature.

Well the 32 rh I have maintained temps when it was 105 degrees out without going through the radiator, that was in 09, don’t remember what it was, but it was Lower when bypassed but still over 200 and I had a gauge in the pan.

 

[Steel City 06]

Case in point the Ford Ecoboost oil cooler mod. I looked it over but didn't see any data supporting it's installation other than claims of improved fuel mileage...which might have come from other mods like a tune, ceramic coating the exhaust and intake and an electric fan.

Nonetheless I pressed on. I installed the oil cooler and I installed a glowshift oil pressure and temperature sensor.

I've tracked enough data at this point to know the mod does more oil heating than cooling...I haven't removed it yet because I'm still researching whether or not that's a good thing or bad...but absolutely zero change in fuel mileage.

-Mac

The Ecoboost mod won't increase steady-state fuel economy, but will likely have a very small increase in startup fuel economy. Unfortunately its effect is small enough that the gains would be very hard to detect in just a single experiment.

There are a number of laboratory tests that show the gain, but a lot of them also show that the oil to exhaust heat exchanger is even better. The numbers I saw in most laboratory tests were in the range of 3-5% reduction in startup fuel consumption (SFC) for the oil-to-coolant, but possibly 8-10% reduction in SFC for the oil-to-exhaust heat exchanger. (The disadvantage of the oil-to-exhaust exchanger is that it is an oil heater only, and does not double as a cooler.)

The main benefit is the extended oil life and reduced degradation from having a more consistent temperature. When oil is too cool, it accumulates volatiles and water vapor, which can react with the oil and reduce its lubricity. When it is too hot, it breaks down significantly faster. The cooler simply clamps the oil temperature to coolant temperature, so it is neither too cold nor too hot. (Hence why you can get 10,000+ mile oil change intervals on the F-150 and other similar vehicles.)

The more consistent viscosity also might have a beneficial effect on reducing engine wear, but this is even harder to quantify.

 

[Steel City 06]

Not only that, the thought that slowing the liquid flow allows it to dissipate more heat is flawed, and goes against the laws of thermodynamics that show faster flow transfers more heat. This is why “high flow” water pumps cause an engine to run cooler - they push the coolant through the radiator faster. You never see a company marketing a “low flow” water pump for a reason.

Really what high flow pumps are doing is maintaining a more consistent temperature around the block. The thermostat controls flow, and will react to changes in pump speed by counteracting the increased flow due to the feedback effect.

Basically, a portion of the water gets circulated through the heater core at all times and back through the block. This is the bypass flow. The thermostat allows a portion of the water to flow through the radiator based on the temperature of the water flowing through the housing.

What the pump will do is push a greater volumetric flow rate of water through the block and through the bypass. The flow through the radiator and the associated delta T won't have appreciably changed due to the thermostat. But since the water is flowing through the block and bypass faster, it has less overall delta T through the block, and mixes more thoroughly with the radiator return water.

So effectively, the mixed water (from the radiator and the bypass loop) going into the engine is closer in temperature to the block outlet water, and also moving through at a higher flow rate. So as a result, the temperature across the entire block is more uniform, and hot spots are reduced.

I suspect in the TJ that the coolant temperature sensor happens to be near a hot spot, hence it will show lower temperature at higher pump flow rates, even if the temperature across the block on average is largely unchanged.

 

[Steel City 06]

It is what it is and your flawed theory, "The ATF is slowed down and has more time in each cooler dissipating more heat..." . You keeping hot oil in the trans longer hurts what you are trying to achieve.

In the OP's case, it actually doesn't matter in terms of cooling capacity if he uses two in series versus two in parallel. Both will have approximately the same cooling power. (I do agree the OP's theory is flawed, though.)

He has roughly the same flow rate and the same dissipative surface area through the entire system regardless of whether they are in parallel or series, so cooling capacity is not changed by choosing either parallel or series. The net dwell time of the fluid in the exchangers is also unchanged.

The only advantage that parallel might have over series is less total pressure drop through the system, which reduces the pumping power required to move a given volume of fluid. (Depending on how the transmission actually pumps the fluid, the slightly lower pressure drop of parallel vs series might actually slightly increase flow. )

 

[MikeE024]

I have removed the thermostat on several vehicles, including the TJ. The result was the coolant temperature stayed around 140ºF. This was all in areas with very hot summer temperatures.

My results were very different last summer when I drove the TJ without a thermostat between system flushes. While it took the coolant temps longer to warm up, the temps were near enough to normal range when driving on the highway and in general sustained driving.

The radiator fan would drop the temps a bit at times when in idle or putzing along in town, but normal sustained driving would heat the temps back up.

 

[JPHikr]

https://www.pegasusautoracing.com/document.asp?DocID=TECH00133
The air temperature difference also means that if we run two oil coolers, they should be plumbed in parallel, rather than in series. If you run two coolers in series, the oil in the second cooler would be cooler (closer to the air temperature) than the oil in the first cooler, making it much less efficient. Another bonus to plumbing in parallel is that it has the same effect as adding more rows to the cooler: Less flow restriction for an even happier oil system.

 

[mrblaine]

https://www.pegasusautoracing.com/document.asp?DocID=TECH00133
The air temperature difference also means that if we run two oil coolers, they should be plumbed in parallel, rather than in series. If you run two coolers in series, the oil in the second cooler would be cooler (closer to the air temperature) than the oil in the first cooler, making it much less efficient. Another bonus to plumbing in parallel is that it has the same effect as adding more rows to the cooler: Less flow restriction for an even happier oil system.


View attachment 628594

Not that I inherently distrust Pegasus but I can't get my head around how air temp affects the efficiency of a heat exchanger. That should be built into the cooler via design and unaffected by temps. What am I missing?

 

[JPHikr]

The air temp affects the amount of heat the cooler can remove from the fluid.
That is why truckers cover the grill of there trucks during the winter.

https://alaquainc.com/6-factors-influencing-heat-exchanger-efficiency/

https://www.sciencedirect.com/science/article/abs/pii/S0306261916305372

 

[mrblaine]

The air temp affects the amount of heat the cooler can remove from the fluid.
That is why truckers cover the grill of there trucks during the winter.

https://alaquainc.com/6-factors-influencing-heat-exchanger-efficiency/

https://www.sciencedirect.com/science/article/abs/pii/S0306261916305372

They should be using effectiveness instead of efficiency.

 

[JPHikr]

Numbers are just for comparison not actual amount of ATF from trans:
ATF is moving at 1gpm from trans. to the coolers.
If that is split into two coolers parallel each is getting .5 gpm,
That is a reduced flow of 50% with less resistance, this means the ATF is spending an increase of 50% longer time as it flows thru each cooler.
Still flowing 1 gpm back to trans.

More time the ATF is in the two parallel coolers the more heat removed as each cooler is the same inlet temp of ATF.
Rather than two in series where the second cooler is getting a lower inlet temp of ATF which will not have as much heat remove because of that lower temp and going thru the two coolers at 1gpm which the ATF is not spening as much time having heat removed.

Think of it as Dwell time when the piston is at TDC and spark has ignited the air fuel mixture which burns not explodes, the longer that burn takes place the more force is pushing the piston down.

 

[Steel City 06]

Numbers are just for comparison not actual amount of ATF from trans:
ATF is moving at 1gpm from trans. to the coolers.
If that is split into two coolers parallel each is getting .5 gpm,
That is a reduced flow of 50% with less resistance, this means the ATF is spending an increase of 50% longer time as it flows thru each cooler.
Still flowing 1 gpm back to trans.

More time the ATF is in the two parallel coolers the more heat removed as each cooler is the same inlet temp of ATF.
Rather than two in series where the second cooler is getting a lower inlet temp of ATF which will not have as much heat remove because of that lower temp
and going thru the two coolers at 1gpm.

Think of it as Dwell time when the piston is at TDC and spark has ignited the air fuel mixture which burns not explodes, the longer that burn takes place the more force is pushing the piston down.

Dwell time is the same overall in series and parallel. Say each cooler is 1/6 gallon in volume. In series, the fluid stays in the first cooler for 10s, then in the second cooler for 10s, for a total of 20s. In parallel, with half the flow, the fluid spends 20s in either cooler. Both ways, you have fluid in coolers for 20s.

The decay gradient of temperature across the length of the coolers is exactly the same between the two setups except for the factor of two relative to length. The first cooler will remove more heat than the second cooler in the series setup, but the total heat rejection is the same in either case. (Same way the inflow side of a single cooler rejects more heat than the outflow side.)

 

[CMBD]

All this theory talk is just jerking off in the wind and speculating if you are not measuring any actual temps. What temp are you chasing? What are you trying to solve?

How is the spin on filter effecting cooling in the OPs setup? (If you don't know, just ask)

 

[JPHikr]

The filter is not rejcting any heat as it is in the hot engine compartment.
I have actually thought of putting a coozy on it to insulate the oil filter from the radiator heat.
It is there to allow me to change a quart od ATF everytime I do an oil change plus filtering the ATF.
The ATF goes from the radiator to the spin on filter, this is also where the fan switch is located. Then to the Derale 20561 and out to the two frame rail coolers mounted ont the front grill for maximum air flow.

Carroll Smith Tune to Win
"When using multiple heat exchangers remember that the greather the difference in temperature between the liquid to be cooled and the air that is doing the cooling, the greater will be the temperature drop across the cooler. First, plumb multiple coolers in parallel rather than in series. Second, do not mount your oil coolers directly ahead of or behind your water radiator. The air coming out of the water matrix is just about at water temperature and won't do much of a job of cooling the oil and vice-versa."

This is why I mounted the in front of the grill rather the right in the AC condenser. by have the stand off on the grill the heat rejected from the coolers has more air flow mixing with the incoming before it reaches the AC conderser.

My goal is to have the lowest trans temp as I can on 115-120 days.