Intercooler and aftercooler?

[NIsaacs]

Does anyone know why this is coming about? I have noticed big trucks are using this combo now, but I don't know why.

My brother just bought a 2019 Ford F-250 and it has both. He asked me why and I couldn't tell him. He did say he thought the intercooler was kind of small compared to the older trucks.

I do know that back in the day, Cummins continued with an aftercooler, long after everyone else went intercooler. They claimed the intercooler was actually too cold at times and was hard on valves and seats.

 

[NIsaacs]

Misdiagnosis, too much junk under the hood. It has an aftercooler only. The intercooler is a second radiator for the aftercooler and engine oil cooler, not an intercooler at all. Very similar to the Cummins big cam 4 system.

 

[bigceltic]

I had never heard the term "aftercooler" so I had to look it up. Learned a lot!
https://www.quora.com/What-is-the-difference-between-intercooler-and-aftercooler-in-engine

"In the past, aircraft engines would run turbochargers in stages, where the first stage compressor would feed the inlet of the second stage compressor that would further compress the air before it enters the engine. Due to the extremely high pressures that would develop, a charge-air cooler was positioned between the first and second stage compressors. That cooler was the "Intercooler".

Another charge-air cooler would be positioned after the second stage, which was the final compressor stage, and that was the "aftercooler". An aftercooler was the cooler whose outlet fed the engine.

This term is now considered archaic in modern automobile terminology since most forced induction vehicles have single-stage superchargers or turbochargers. The term intercooler is widely used to mean in-between the Turbocharger and the engine. Both terms, intercooler or aftercooler, are correct, but this is the origin of the two terms that are used interchangeably by all levels of experts."

 

[BSeyler]

I had never heard the term "aftercooler" so I had to look it up. Learned a lot!

I guess those terms date some of us! Many years ago they were called air to water/air to liquid aftercoolers and air to air aftercoolers. That’s how I still refer to them. My son just rolls his eyes when I say my Cummins has an aftercooler. My two stage shop compressor has a cooler after the first stage and a cooler after the second stage. In the owners manual it refers to the first one as an intercooler and the second one as an aftercooler.

 

[TFucili]

You're right. Intercooler has become a catch-all name, it seems. I am as guilty as anyone. I'll revert to CAC, Charge Air Cooler

 

[Wayne M.]

The ford 6.7 has a CAC just like all diesels have today. The confusing thing, Nick is that it’s not a air to air heat exchanger. It’s a air to water heat exchanger, just like the ‘80’s engines indeed had, at the cylinder head, and they were called aftercoolers. That hunk of aluminum packed next to the left battery is indeed the CAC. That engine has 2 cooling systems with 2 tanks and belt driven water pumps. It’s a complicated system.
Regarding the intercooler being too cold for the engine, I remember certain ‘80-‘90’s Mack arrangements had intercooler bypasses. Air cylinder controlled valves that routed the charge air around the intercooler, and right into the engine.

 

[NIsaacs]

Thanks Wayne, for the Ford lesson 101 I don't think I would even open the hood if it were mine. The belt is 141" long, that's more than the wheelbase of my '01! Two alternators, two water pumps, power steering pump, fan, crank, A/C and belt tensioner, did I forget any, lol The belt drives on both sides. Two thermostats, one is 201* and one is 194*, not sure which is which.

Do you know why Ford went to water cooled CAC v/s Air cooled CAC?

 

[JR]

Fords messed with liquid to air chargers prior to the 6.7, I remember seeing certain SVT models (Lightening, Cobra Terminator) Implementing them in the early 2000's. The Shelby GT500 also uses one, so I think its kinda just a Ford thing. Supposedly they are more efficient than air to air and require less space, but it also adds in complexity.

 

[TFucili]

Two water pumps, like a flathead. Can you get Offenhauser heads for them?

 

[NIsaacs]

Two water pumps, like a flathead. Can you get Offenhauser heads for them?

You failed to mention Ford V/8 or Lincoln V/12, just flathead don't get it

 

[Wayne M.]

Thanks Wayne, for the Ford lesson 101 I don't think I would even open the hood if it were mine. The belt is 141" long, that's more than the wheelbase of my '01! Two alternators, two water pumps, power steering pump, fan, crank, A/C and belt tensioner, did I forget any, lol The belt drives on both sides. Two thermostats, one is 201* and one is 194*, not sure which is which.

Do you know why Ford went to water cooled CAC v/s Air cooled CAC?

View attachment 110149

Yes the belt is very long! The 6.7’s are actually better thought out than the previous ‘strokes. That said, it’s still tough getting some basic things done underhood. Undress to operate is still the motto. I do not know the real reason for the cooler design, has to be space issues.

 

[Ozymandias]

Nowadays are many car engines around with 2 and even 3 Turbo chargers (BMW), so, well, the term inter- and aftercooler makes sense again.