Cummins Jacket Water After Cooler (JWAC) upgrade

[davegonz]

Just thought I’d post up my water-air intercooler project. I’ve been suffering from really long cool down times before shutting down the engine and have attributed it to the way Cummins cools the JWAC (Jacket Water After Cooler). The stock 4BTA JWAC is cooled via the engine coolant (180-200F). So there is very little temperature delta between the hot compressed air (post turbo) and the engine coolant in the JWAC. So, my plan is to plumb in a dedicated coolant circuit with a front mounted radiator and electric fan.
Here are some reference links that I got info/ideas from:
4BTswaps: 4BTA aftercooler mods?

FirstToy’s post: https://forum.ih8mud.com/80-series-tech/394197-waic-water-air-intercooler-trd-sc.html
My primary parts source has been frozenboost.com. I ordered everything from them and have been happy with the quality, price, and delivery.

Here's a simple block diagram of what I'm doing.

 

[davegonz]

I installed the radiator and the fan. I had to modify the hell out of the grill and the center support bracket, but it fits. Next up will be the Bosch water pump.

 

[gifu]

great work. This is how these should have been done from the beginning.
You might need a secondary water fill point that is higher up in order to get all the air out of the system. Very interested to see before and after EGTs.

 

[davegonz]

The JWAC assembly has a vent on top that you open up when filling. I'm hoping that is enough to get all the air out.

 

[Adam B]

That's funny. Assuming that's the 12x12x2" radiator I installed the exact same unit in the same place. I had to modify the hood support a bit less than you did. I also had a lot of smelly fun with a die grinder removing about 3/4" from the back side of the grille on that side! I ended up using my fan as a puller on the back side of the rad so I probably had to grind more grille than you did.

Nice work.

 

[davegonz]

LOL! Yeah, those nasty fumes from the plastic gave me a headache and possibly lung cancer

I just about got it flush, but will need to grind away a little more.

 

[davegonz]

For reference, here's how the inside of a JWAC looks like (6BT version).

 

[davegonz]

I'm finished! I added a fan controller and wired everything up. My EGT's are way lower and my cool down times were cut by more than half.

 

[PhrogsPhorever]

That turned out real nice That was what I was researching before the Yeti went to Austin. Good to se the EGT and cool down got better

 

[davegonz]

Thanks Alex. All it really needs now is some gears.

 

[cody c]

Where did you get the JWAC from? And is it the same for the 4BT and 6BT? Im guessing the 6BT has a wider intake manifold flange.

 

[davegonz]

Yeah, it came stock on the 4BTA. I think Cummins sells two different versions of the 4BTA. One with the JWAC and one using an air-air intercooler. Scroll up and you can see how a 6BT one looks like.

 

[cody c]

ya I was just looking for aftermarket or NOS products.

My 6BT is out of a 91, so apparently its got slightly bigger injectors then the next couple years, but no intercooler.

I see there is a few at the alibaba site: http://www.alibaba.com/product-gs/339777984/Cummins_parts_water_after_cooler_jacket.html

Water after cooler jacket 6BT Cummins parts - Detailed info for Water after cooler jacket 6BT Cummins parts,Water after cooler jacket,Water after cooler jacket 6BT Cummins parts,6BT on Alibaba.com

It would be a nice upgrade for the 6BT.

 

[davegonz]

Check out this site. I bought most of my intercooler parts from them. They sell air/water intercoolers that will be the same (or better) than the Cummins one.

Air to Water Intercooler

Also, the downside to you retrofitting a Cummins style JWAC is that you'd have to get new fuel lines to route around the Cummins JWAC assembly. With an aftermarket air-water IC, you can use the same intake horn with out any interference with the fuel lines coming from the injection pump.

 

[cody c]

Check out this site. I bought most of my intercooler parts from them. They sell air/water intercoolers that will be the same (or better) than the Cummins one.

Air to Water Intercooler

Also, the downside to you retrofitting a Cummins style JWAC is that you'd have to get new fuel lines to route around the Cummins JWAC assembly. With an aftermarket air-water IC, you can use the same intake horn with out any interference with the fuel lines coming from the injection pump.

Ah crap I didnt even think about the fuel lines, I thought it would be plug and play.

I guess one of the hose places in town should be able to build them but I dont think it would be cheap.