Pre cooler....

Are you referring to "pre-cooling" a reefer trailer?

 

If this is in relation to a turbocharger having a precooler this thread should be moved to the garage section. The turbo is warmed by the exhaust. When you compress air, it gains heat as well. If you precool the air before it gets into the engine you will do several things. Air becomes more dense when it is cooled. Cool compressed air in a diesel engine will make more horsepower than air coming straight out of the turbo or atmospheric air. Diesel fuel has been found to burn better the more air you can get into the chamber the better. If you have black smoke coming out of a diesel you are not getting a good complete burn. So the idea is to get the most air into the cylinder for combustion to give the best horsepower / mpg for the fuel.


I hope that answers your question.

 

The location of a precooler is in front of the radiator. It looks exactly like a radiator, except that it has warmed air in it instead of coolant. As the truck goes down the road the truck uses windchill to help further cool the air.

 

I thought that was the charge air cooler or the air to air cooler .
Hmm learn something new everyday!!!

These new fangeled terms LOL .
I guess we don't use dinosaur treats get the truck to move anymore either huh ?

Boy those were the days when you squeezed your fuel right out of the dinosaur yourself !!!

 

The precooler has many other names. As posted by Marmonman "charge air cooler". Another name is the intercooler.
The picture below shows the edge of the precooler. It has the blue rubber hoses connecting it to the chrome pipe. (just an image I googled)

 

The precooler has many other names. As posted by Marmonman "charge air cooler". Another name is the intercooler.
The picture below shows the edge of the precooler. It has the blue rubber hoses connecting it to the chrome pipe. (the image came from Kustom Truck website)

 

If you are talking about an ACERT cat then the precooler does mean something different, there is a small cooler that the air right out of the turbo goes through that uses engine coolant to give the cooling a head start before it enters the air to air.

 

The thing in front of the radiator is a CAC, charge air cooler, also known as the air-to-air cooler. In light duty they're known as intercoolers. They can be called a pre-cooler to, but it's not a common name for them.

A pre-cooler is a liquid (antifreeze) to air cooler up stream of the CAC. Cat Acerts are the most well known for them and are mounted right behind the water pump. Hot compressed air from the turbos goes through the pre-cooler, which is similar to a heater core, to reduce temps a bit so that the CAC can be more effective.

 

I knew a guy with a Ferrari that had twin turbo intercoolers. One bad motor. They help removed the waste heat. The cooler the air the more dense it is which improves combustion.