Charge Air Cooler?????????

jackhartjr · August 05, 2009, 03:01:33 PM

Hi folks, without sounding like an idiot, (Be nice Kyle)...what is a Charge Air Cooler...and what does it do?
Thanks in advance!
JAck

John316 · August 05, 2009, 04:03:47 PM

Jack,

I really don't know, BUT I will take a guess. My guess is that it is the air cooler for the turbo. In ours it looks like a radiator, but somehow cools air for the turbo....

I really don't know though. I just thought that I would put my guess up, to see if I was correct.

God bless,

John

belfert · August 05, 2009, 05:17:15 PM

John is correct. Air going into the engine is cooled through the CAC or intercooler. Cooler air is more dense and has more oxygen.

jackhartjr · August 05, 2009, 06:24:01 PM

Ok, good so far.
How does it cool..in other words does it use air or some sort of fluid to cool the air?
Thanks
Jack

luvrbus · August 05, 2009, 06:48:39 PM

Jack, I'll try and help on the Air to Air the air goes from the turbo at about 500 degrees through the cooler that is cooled by the outside air and then to the engine at around 200+ degrees.
It just uses the air like a radiator only without water.
On the aftercooler it uses water to cool the air after the turbo.
Have you ever noticed when you are driving your rig how in the rain and at night how much more power you seem to have , cooler air makes more power clear as mud huh

good luck

NewbeeMC9 · August 05, 2009, 06:56:22 PM

Jack! Don't make me go Wiki on your a$$!!

http://en.wikipedia.org/wiki/Charge_air_cooler

Same as Intercooler but generally different in size.

Thanks Jack for a little learning

jackhartjr · August 05, 2009, 07:46:57 PM

Starting to make sense now, thanks to all who answered.
Clifford, yep, they do run good cold!
The one I drive now LOVES the air at about 70 degrees, purrs like a kitten!
Jack

pato-06 · August 06, 2009, 05:53:09 PM

For every pound of boost you create 12 degrees of heat over ambient temperature. Example 100 degree day 20 pounds boost ,you would have 340 degee going into intercooler. I can get my intake temp. to 40 degrees over ambient. Pat

Utahclaimjumper · August 06, 2009, 06:50:13 PM

I have a ummins ISC 8.3 with turbo and Charge air cooler, the air is drawn into the air cleaner, then to the turbo to be compressed, then thru the GAC (its mounted in FRONT of the radiator) then into the engine, works great .>>>Dan

TomC · August 07, 2009, 08:26:56 AM

To show how well air to air intercooling works, virtually every Diesel engine in vehicles now (and for many years past) is both turbocharged and air to air intercooled.

When I turbocharged my 8V-71N, I had a custom air to air intercooler made for infront of the radiator (helps I had about 8" to play with). Don Fairchild, who had been working on 2 stroke Detroits most of his life, did the work and was the first one he had done. It works so well, Don has done numerous additional ones for other busnuts.

Bottom line- Turbocharging and air to air intercooling a 2 stroke Detroit REALLY wakes them up. Going to Las Vegas from L.A., I pull the Cajon pass and Baker pass 10mph faster, and they are the only two hills I have to down shift on. All other hills the bus goes over without down shifting-compared to numerous slow downs and down shifts before the turbo. Good Luck, TomC

Michael_e · August 07, 2009, 10:46:06 AM

I curious now. I've got an 8V92 Turbo aftercooled engine. Can a charge air cooler be installed to this setup and would it do any good? Would it be better to remove the aftercooler portion and just run the engine with the air charge cooler setup? Should i just back away form the keyboard and go back to yard work? Thanks, Mike

luvrbus · August 07, 2009, 11:14:12 AM

Mike, that was a option for the 8v92T from the 80's really brings them to life with more power more torque and better fuel mileage.
There are 2 of us I know of now doing that, I had to have the manufacture redo my air to air because of space and because I didn't want fans on mine.
And yes you do need to remove the after cooler and install a air defector in place of the after cooler some don't add the defector but I am going to add it just like the book shows.
Space for the air to air is a problem on older buses but the manufactures can work it out and give you enough air flow and if you don't mind fans they are easier to install.
FWIW mine and JIm's air to air units were around 1000 bucks plus piping

good luck

NJT 5573 · August 07, 2009, 11:34:09 AM

Michael,

Its probably about an equal trade off.

The intercooler sits in front of the radiator and the heat is released into the air around the radiator fins, slightly increasing the air temp hitting the radiator.

The aftercooler sits under the blower or in the intake airstream after the turbo, (4 stroke), and uses coolant to transfer the heat from the intake airstream into the coolant.

When aftercoolers and intercoolers first hit the market, the mechanics used to tell me I didn't need one with straight pipes because I didn't have a heat build up as I had no back pressure on the exhaust. I never proved or disproved that, but I think there is some truth to it.

Aftercoolers are usually aluminum and rarely leak air. Air to air intercoolers are generally plastic and have a lifespan that sometimes requires replacement. The intercooler will also be a little more maintenance sensitive because you have to keep the clamps/pipes etc. tight or you will not have any boost when it gets back to the engine.

Both can give you some free horsepower and improved fuel mileage.

luvrbus · August 07, 2009, 11:49:43 AM

Mike, everyone does it their way the aftercooler on the 2 strokes are not real efficient the one on a 8v92 is 4 inches wide , 12 inches long and 3 inches deep.
You don't get much cooling from a cooler where it sits down in the block between 2 heads and are level were the combustion takes place and water is 180+ and that is a small area plus going through the blower and making more heat.
Our air to air units are made from aluminum

good luck

belfert · August 07, 2009, 11:58:21 AM

The intercooler/CAC on my bus is metal, probably aluminum, and it is almost as big as the radiator. Mine is in front of the radiator and it is a factory install. It somehow had some holes in it when I got the bus and a local radiator shop patched it up.

I have had to remove the intercooler two or three times to work on the engine (mostly cooling stuff) and I can get the intercooler out in less than an hour by myself. The intercooler is designed to be easy to work on unlike other things like the radiator! (It took half a day or more to remove the radiator.)