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Geek time for engine coolers

 

In racing applications engine oil coolers are used because the oil is higher temp than the water (higher delta t to the air cools better per cfm air used). They are also used if the oil temp to water temp diff is too great (oil too high, cooking the oil when the water temp is fine). You can often have higher fin density in an oil cooler, because the pump pressure is much higher. This can make the oil cooler more efficient per cfm air than a water cooler alone. 

 

Most racing rads are sized to either be very low cg, short and thick, for lower speed cars, or very efficient (big and high fin density) for big aero cars. Nascar "aero" rads are 30 lbs and require 60ish mph static pressure to even cool at all due to the fin density. Ironically champ guys often pay points for lower fin density "performance" rads vs the oem, mainly because the thinner fin density have thicker walled tubes that can take more damage. 

 

If you aren't chasing the CG or the aero (champ guys have grill opening sizes that clearly scream "don't care that much about aero"), then you should only need an oil cooler because your oil vs water temp split is too high, or you cooling system and ducting is not enough to cool the engine on the water side alone (both run high but split in oil to water is normal 30-50 deg). The engine design will dictate how well the oil temp makes it into the water (usually thru the block and head). OEM applications often use water cooled oil coolers to lower the temp difference, and if you have reserve water cooling capacity (get your ducting right, majority of cars have tons of reserve) and aren't restricting the rad air to the point efficiency matters that much, it can be an easy safe way to close the delta temp. I would use the oe S10 oil cooler loop and watch the oil to water temp delta before going non oe cooler

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1 hour ago, mgoblue06 said:

 

So looking at our radiators we have the one shown above that includes hookups to cool two oil fluids along with the water, and the original AC condenser.

 

I think we will set it up like this, please let me know thoughts?

 

AC Condensor - Engine oil (sits in front, and if we keep this the coolest it will be easier to cool the others via radiator)

Radiator - Rear Diff on one side, transmission on the other side

 

The above would be 0 points correct using all OE coolers? Any disadvantages to this system?

 

Efans will probably be used as well

 

 

   How are you going to get the rear end fluid to the cooler and back, circulate, pump = points 

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16 hours ago, Black Magic said:

Geek time for engine coolers

 

In racing applications engine oil coolers are used because the oil is higher temp than the water (higher delta t to the air cools better per cfm air used). They are also used if the oil temp to water temp diff is too great (oil too high, cooking the oil when the water temp is fine). You can often have higher fin density in an oil cooler, because the pump pressure is much higher. This can make the oil cooler more efficient per cfm air than a water cooler alone. 

 

Most racing rads are sized to either be very low cg, short and thick, for lower speed cars, or very efficient (big and high fin density) for big aero cars. Nascar "aero" rads are 30 lbs and require 60ish mph static pressure to even cool at all due to the fin density. Ironically champ guys often pay points for lower fin density "performance" rads vs the oem, mainly because the thinner fin density have thicker walled tubes that can take more damage. 

 

If you aren't chasing the CG or the aero (champ guys have grill opening sizes that clearly scream "don't care that much about aero"), then you should only need an oil cooler because your oil vs water temp split is too high, or you cooling system and ducting is not enough to cool the engine on the water side alone (both run high but split in oil to water is normal 30-50 deg). The engine design will dictate how well the oil temp makes it into the water (usually thru the block and head). OEM applications often use water cooled oil coolers to lower the temp difference, and if you have reserve water cooling capacity (get your ducting right, majority of cars have tons of reserve) and aren't restricting the rad air to the point efficiency matters that much, it can be an easy safe way to close the delta temp. I would use the oe S10 oil cooler loop and watch the oil to water temp delta before going non oe cooler

 

So is the reason a cost saving?

 

If the car has an oil cooler the manufacturer can save cost with:
- have a smaller rad  (size and cost)

- have a suboptimal oil->water "heat transfer". Makes manufacturing cheaper?

 

If the government banned oil coolers (why not), the manufacuterers would have to run mega sized radiators and very complex cooling channles in the block?

 

(I do think they also have water to oil exchangers to heat up the oil quicker for emissions)

 

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6 hours ago, turbogrill said:

 

So is the reason a cost saving?

 

If the car has an oil cooler the manufacturer can save cost with:
- have a smaller rad  (size and cost)

- have a suboptimal oil->water "heat transfer". Makes manufacturing cheaper?

 

If the government banned oil coolers (why not), the manufacuterers would have to run mega sized radiators and very complex cooling channles in the block?

 

(I do think they also have water to oil exchangers to heat up the oil quicker for emissions)

 

 

For OEM applications? 

 

If the oil to water temp delta (difference) wasn't greater than desired, there wouldn't be enough justification to build oil cooler lines and the cooler for OE application. This obviously depends on the design performance envelope (grandma car or designed as a track car). The "water oil coolers" also help get the oil up to temp, again the goal being to keep the water to oil temp split lower. Oil temps that are too cold leave lots of moisture and crap in the oil, too hot and you kill the durability of the oil. Those are the main goals for OE. 

 

Since engine block designs tends to have very long runs, it is pretty unlikely the OEMs would be able to accurately predict oil heat rejection to the water for all combinations of final engine build. Consider most of our cars OE blocks were designed either before or during the dawn of thermal CFD, and you can see why oil coolers on some street cars pop up. Redesigning the block to have more oil paths near more coolant paths would be a major expense, and given some casting quality a major risk. About the best you can do is try to reduce the amount of oil splashing on the piston back sides, well except for those turbo applications where the OE design adds piston squirters ....

 

Looking at "water oil coolers" on newer cars that sandwich to the oil filter, they only require 2 external coolant lines to be run (typically t off the heater core hoses) and offer a cheap way for OEMs to replicate "adding more cooling channels in the block (for oil to water)". If these were somehow banned than yes, you would see them built into the pan or block. Interestingly you typically see these added to engine blocks that have had significant power\boost added since the original engine was designed. 

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