Aftercoolers

[skipm]

Tell me all about them.

[Mistress]

Their purpose?

They cool the aircharge after being heated up by the turbo. This allows more boost, which means more air, which means more fuel can be dispensed without overheating the cylinders. In the automotive world they're called intercoolers..but in actuality, they are aftercoolers.

A rich mixture in a gasser burns cool. A rich mixture in a diesel burns hotter. You can never have too much air pumping through a diesel.

[skipm]

So do they make aftermarket ones?

[Pedlyr]

skip-

First off, aftercoolers typically sit on or in the "V" of the engine. I don't think you can buy a unit and bolt it on, since you typically will have to move some parts to make space.

Of course you might be able to buy one from the engine manufacturer if they offered it for your particular engine as an option and fit it. But now you will also have to change the turbo and air horns. Plus, the fuel settings/ injectors may have to be changed or adjusted.

FWIW, I have hardly seen good luck with salt water aftercoolers. I have witnessed many engines ruined by salt ingestion as a result of an internal leak.

[Mistress]

All the higher output Cummins have them. That's what makes a 6BT into a 6BTA. I suspect to get value out of it though, you'd need bigger injectors, a bigger turbo and injector pump mods or swap. Of course then you need to keep the whole engine cool with more water.

The goal of an aftercooler...like I said, is to get more air at a reasonable intake temp, so you can add more fuel. More air/boost alone, does nothing for generating power. This is a different game than an injected gasser, inwhich if you increase the boost, the electronics correspondingly dump more fuel in order to keep the air/fuel ratio correct. Diesels don't care about air/fuel ratio for the most part. Fuel is power, air keeps it safe.

Turbos have an efficiency map. After a certain point they aren't compressing much and just overheating the air. I don't know about the higher output engines, but the 210 has no wastegate..therefore it is designed to create no more boost than the "system" can handle. My Cummins truck came stock at 20 psi max boost. The turbo doesnt run out of it's mapping until about 35 psi. To turn it up, the truck has oversize injectors, the wastegate has been "tricked" and the electronic injector pump has effectively been reprogrammed. A bigger turbo can pump more air, more effciently, but the trade off is low end boost and turbo lag. Particularly on a mechanical diesel...everything is a sytem. There's no external adjustments on the Lucas CAV pump. The Bosch pump does.

What's your goal?

[skipm]

Well I,m not going to sacrifice 6BT210 reliability for a little more power.Besides I'd have to re-prop, then my idle mph goes up.I'll stay where I am thanks for the help guys.

[Mistress]

I havn't heard of any real problems associated with the Cummins 6BTA250....but requires considerably more than adding the A to get there. That additional 40 hp's would be at least $100 per hp just in parts is my read...prolly more for best longevity. And ya...idling at 5.5 knots is more than plenty...LOL