Engine oil cooler
#1
03-03-2010, 07:06 AM
Engine oil cooler
Part1 / Theoretical thoughts
Engine oil cooler
Fighting constantly against engine heat issues and heat related engine failure gave me the idea to share my solutions and thoughts with others.
Theoretical thoughts
According to automotive sources, engine oil in the pan should have a temperature between 176°F (80°C) and 212°F (110°C) depending on engine size and outside temperatures to minimize wear.
Most cars and trucks don’t have an engine oil thermometer anymore. The common driver waits to hit the throttle until coolant has warmed up.
This is a major mistake. It takes up to 20 minutes longer to reach proper operating oil temperatures depending on outside temperatures and engine load.
Oil temperature is a direct indicator for the thermal load or overload of the engine. So an engine oil thermometer is a necessary add on for every bombed truck with more power than stock.
We should have in mind that engine oil has its best lubing abilities around 212°F (100°C).
Anything below 176°F (80°C) increases wear and fuel consumption.
When does heat develop?
Heat develops under load like hard pulling or during speed when the engine has to fight against wind resistance.
A common solution is to add an engine oil cooler in front of the radiator.
This has two disadvantages:
- it blocks the radiator wind flow
- the cooler unit only works with provided wind flow through the fins
Heat also develops due to poor engine design.
Just have a look at that poor Cummins I6 engine air intake design. The front cylinders run with a lot of air and the rear ones are starving for air. Injected fuel is always the same in every cylinder. Air starvation leads to higher exhaust temperatures in the rear cylinders.
You can check that easily with a thermal gun. And you will recognize that the rear runs hotter than the front increasing engine temperatures about 10°.
What about wind flow during pulling heavy loads like a trailer? Or pulling of the highway and decreasing the necessary speed to provide efficient cooling?
We all (equipped with an engine oil thermometer) have recognized that engine oil temps are lowering themselves very slow after a high load (it seems they take forever to reach the usual temperatures again during the summer).
How can we increase cooling efficiency?
We simply have to take out the speed varying air flow of the equitation.
A simple fan with a sufficient air flow can provide constant heat dissipation.
It also makes it possible to locate the cooling unit as short as possible to the engine to avoid unnecessary hose length and to prevent unnecessary oil pressure drop.
Every 45° angle causes a pressure drop of 2 psi and every 90° angle causes an additional 5 psi drop in the oil system.
The fan solution provides a speed independent constant air flow through the cooling fins of the oil cooler.
A second advantage is that the fan activating temperature point and run time can be set independent of influencing factors.
E.g. after a hard step pull up on a hill, the oil cooler remains active until the temperature is quick back to normal.
This also provides a constant equal engine load.
To be continued with Part 2/ the build
Engine oil cooler
Fighting constantly against engine heat issues and heat related engine failure gave me the idea to share my solutions and thoughts with others.
Theoretical thoughts
According to automotive sources, engine oil in the pan should have a temperature between 176°F (80°C) and 212°F (110°C) depending on engine size and outside temperatures to minimize wear.
Most cars and trucks don’t have an engine oil thermometer anymore. The common driver waits to hit the throttle until coolant has warmed up.
This is a major mistake. It takes up to 20 minutes longer to reach proper operating oil temperatures depending on outside temperatures and engine load.
Oil temperature is a direct indicator for the thermal load or overload of the engine. So an engine oil thermometer is a necessary add on for every bombed truck with more power than stock.
We should have in mind that engine oil has its best lubing abilities around 212°F (100°C).
Anything below 176°F (80°C) increases wear and fuel consumption.
When does heat develop?
Heat develops under load like hard pulling or during speed when the engine has to fight against wind resistance.
A common solution is to add an engine oil cooler in front of the radiator.
This has two disadvantages:
- it blocks the radiator wind flow
- the cooler unit only works with provided wind flow through the fins
Heat also develops due to poor engine design.
Just have a look at that poor Cummins I6 engine air intake design. The front cylinders run with a lot of air and the rear ones are starving for air. Injected fuel is always the same in every cylinder. Air starvation leads to higher exhaust temperatures in the rear cylinders.
You can check that easily with a thermal gun. And you will recognize that the rear runs hotter than the front increasing engine temperatures about 10°.
What about wind flow during pulling heavy loads like a trailer? Or pulling of the highway and decreasing the necessary speed to provide efficient cooling?
We all (equipped with an engine oil thermometer) have recognized that engine oil temps are lowering themselves very slow after a high load (it seems they take forever to reach the usual temperatures again during the summer).
How can we increase cooling efficiency?
We simply have to take out the speed varying air flow of the equitation.
A simple fan with a sufficient air flow can provide constant heat dissipation.
It also makes it possible to locate the cooling unit as short as possible to the engine to avoid unnecessary hose length and to prevent unnecessary oil pressure drop.
Every 45° angle causes a pressure drop of 2 psi and every 90° angle causes an additional 5 psi drop in the oil system.
The fan solution provides a speed independent constant air flow through the cooling fins of the oil cooler.
A second advantage is that the fan activating temperature point and run time can be set independent of influencing factors.
E.g. after a hard step pull up on a hill, the oil cooler remains active until the temperature is quick back to normal.
This also provides a constant equal engine load.
To be continued with Part 2/ the build
#2
03-13-2010, 05:19 PM
Diesel Fan
Makes sense
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