SoCalDesertRider wrote:
A long time ago, Detroit Diesels had aftercoolers. I know the TA stood for Turbo Aftercooled.
I assume the aftercooler was placed after the turbo on the intake side? It seems intercoolers must have proven to work better than aftercoolers at cooling the intake air going into the engine? Does anyone use aftercoolers anymore?
Glen, I think there is just a semantics issue here. I'm not sure how you are interpreting my previous post, so let me clarify.
The intercooler on the 7.3L is an "inter-mediary" cooler, hence the name "inter-cooler". It installs in-between the turbo and the engine, "inter-connecting" those two air pumps (the compressor, and the engine).
In my earlier post above, I discussed how the intercooler cools the intake air of the engine. And I meant just that. The engine pump. Not the compressor pump.
The compressor pump heats up the ambient air it compresses, significantly. Then this hot, pressurized air enters the intercooler, which cools down the super heated air. This "cooled" air is still hotter than the ambient air that entered into the compressor, but without the intercooler the air would have been 100 degrees hotter, and thus less dense with oxygen molecules per unit volume that is available in the cylinder.
It sounds like the DD style TA "aftercooler" you are looking for is indeed the self same "intercooler" on the 7.3L. There does not appear to be any difference between the two, from your description.
To understand the semantic difference between intercooler and aftercooler, I'd have to use a non engine example, like my two stage Ingersoll Rand Type 30 air compressor. The two cylinders in the air pump each serves as a separate stage. Air enters into the first cylinder, and gets compressed. Then, before this compressed air is routed to the second cylinder to get even more compressed, it is first routed through an intercooler (a roll of finned copper tubing surrounding the flywheel fan).
After being intercooled, the air enters the second cylinder for the secondary stage of compression. Then, this highly compressed, high pressurized air would normally fill the 80 gallon tank, but instead, the final compressed air is routed to an aftercooler (a radiator like core mounted to the belt guard). So, in the case of this two stage air compressor, there is both an intercooler AND an aftercooler, and they are not the same. One cools the compressed air between stages, the other cools the compressed air AFTER all compressing stages are complete.
This is not the case with the turbocharged diesels having just a single turbo. Whether a manufacturer chooses to call it an intercooler or an aftercooler, in the case of cooling the compressed air for the engine's consumption, the terms (or at least your meaning of the terms as expressed above) are interchangeable when it comes to the 7.3L. Most call it an intercooler.
