Air-water CAC/intercooler on an IDI?

jaluhn83

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Did it on mine. HX35, running up to about 20 lb boost. Never put any instruments on it to see how effective it was, but seemed to work out ok.

Biggest thing I found is that it was difficult to keep the system full of coolant, I think because there was no expansion volume and no vent off the top of the radiator.


https://www.oilburners.net/threads/air-to-water-intercooler.67709/#post-794885
 

Fision

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Did it on mine. HX35, running up to about 20 lb boost. Never put any instruments on it to see how effective it was, but seemed to work out ok.

Biggest thing I found is that it was difficult to keep the system full of coolant, I think because there was no expansion volume and no vent off the top of the radiator.


https://www.oilburners.net/threads/air-to-water-intercooler.67709/#post-794885
Thanks for the feedback and link.
You also have my curiosity up with the hx35. How do you like it? Do you have a build thread?
 

Booyah45828

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Did it on mine. HX35, running up to about 20 lb boost. Never put any instruments on it to see how effective it was, but seemed to work out ok.

Biggest thing I found is that it was difficult to keep the system full of coolant, I think because there was no expansion volume and no vent off the top of the radiator.


https://www.oilburners.net/threads/air-to-water-intercooler.67709/#post-794885

That's one of the cleaner installs that I've seen yet.

I don't like seeing the intercooler right on top of the engine, and I would think a person would have a hard time bleeding the air out of it mounted high like that.

How you have yours mounted looks like it wouldn't have that issue.

Where is everyone mounting there pump in these things? Is it mounted off the tank and pushes coolant through the radiator and then intercooler?
 

jaluhn83

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Thanks for the feedback and link.
You also have my curiosity up with the hx35. How do you like it? Do you have a build thread?

I like it. Seems to spool up well and easily gets to 15-20 psi. Not sure if it would go higher with wastegate adjustment or not (set as the stock cummins setting, which IIRC is about 18 psi). My setup is a fully custom mount/piping and while it fits well there, I think you'd have clearance issues on a standard aftermarket turbo mount/up-pipe.

That being said, there's seem to be a lot of people who will claim it's a bad choice, however I think that's all based on folks who think they're book smart and haven't actually used on. My $0.02, it's a good setup. I have no EGT issues and feel like it gave about 50% power improvement over a Banks WG setup. Never run on a dyno, but I can do 55-65 on a 4-5% grade at ~15k gross and 40-45 on a 5-6% at ~20k gross. That's with a Typ4 cam, ~0.015" decked & ceramic coated pistons & studs but otherwise stock 6.9. Had to pull the engine at about 75k due to a cracked piston (plugged oil jet, probably shortly after the rebuild) and the internals were all in good shape.

Probably is a build thread somewhere on here, but not sure where.
 

u2slow

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What would concern me is the overall sizing of the cooling system with the addition of the air/water CAC. Especially if an auto trans in competing for cooling. IDIs by nature are 'hot heads' and need a larger system (radiator) than a similar-sized DI engine.
 

jaluhn83

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The air/water intercooler is a separate radiator, so no direction additional load on the cooling system. Admittedly you're limited by the same amount of air flowing through the radiator/cooler stack on the front of the truck, but you have the same thing with an air to air cooler. Air/water could actually help that because it gives you somewhat more flexibility in mounting the radiator.

I didn't have any cooling issues with my rig, and did a number of heavy trips over socal mountain passes in the summer. That being said, I also have a full lockup electromagnetic fan clutch, so part of that may be the ability to manually lock the fan on at the bottom of a hill instead of waiting to hit 220. I think max coolant temp I would see was about 225 at the top of a hill. It would steadily and slowly go up though, so on a very long grade it might get to where you'd need to come off the throttle some, but was never an issue for me.
 

u2slow

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The air/water intercooler is a separate radiator,...

Interesting arrangement. I'm used to seeing them piggybacked into one large cooling system.

Is the CAC loop thermostatic? Dedicated loop? or constantly exchange water in/out of the main radiator?
 

jaluhn83

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Most of the stock aftercoolers do use a similar system, with the cooling system then sized to accommodate the added heat load. Downside is you're not cooling air below coolant temps, on the flip side it's simpler and more space efficient than air to air.

The air to water uses a fully separate loop with it's own pump & radiator. The radiator on mine is 24x24x1" thick IIRC - pretty similar in size to the AC condenser. No real analysis on if it's the right size, nor was I ever able to take measurements on it in operation but that's the largest they had IIRC. The pump is a small electric pump, maybe a boat bilge pump? Control is a bit harder, I was going to make up a IAT controlled system but never did and it was always just on a switch for me. You do probably get some thermostatic flow with the way it's setup, but probably not enough to do much.
 

ocnorb

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Towcat put my original install in the IDI Tech Articles way back in the day.

https://www.oilburners.net/threads/idi-in-the-fast-lane-or-water-air-intercooler-report.51320/


Separate cooling systems means the IC doesn't have to try and shed engine heat- which makes it more efficient. I also chose to run a different color antifreeze in mine so I can tell right away which system is leaking if it happens.

The pump has been very reliable. I just have it on a relay wired to igntion 'ON' so it is always running whenever the truck is.

My next experiment is to add a small aluminum tank on the frame rail to "store" some of that cooled water to see how much the extra capacity helps.
 

Fision

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I like it. Seems to spool up well and easily gets to 15-20 psi. Not sure if it would go higher with wastegate adjustment or not (set as the stock cummins setting, which IIRC is about 18 psi). My setup is a fully custom mount/piping and while it fits well there, I think you'd have clearance issues on a standard aftermarket turbo mount/up-pipe.

That being said, there's seem to be a lot of people who will claim it's a bad choice, however I think that's all based on folks who think they're book smart and haven't actually used on. My $0.02, it's a good setup. I have no EGT issues and feel like it gave about 50% power improvement over a Banks WG setup. Never run on a dyno, but I can do 55-65 on a 4-5% grade at ~15k gross and 40-45 on a 5-6% at ~20k gross. That's with a Typ4 cam, ~0.015" decked & ceramic coated pistons & studs but otherwise stock 6.9. Had to pull the engine at about 75k due to a cracked piston (plugged oil jet, probably shortly after the rebuild) and the internals were all in good shape.

Probably is a build thread somewhere on here, but not sure where.

I cheated- went to your profile page and found the threads you’ve started. Haven’t had time to get far into ‘em. Nice write up on “hx35 results”. From many things I’ve read Holset makes an excellent, responsive turbo. I’d love the range and output of the HE 351VE, but it’s huge and actuating the vanes accurately would be tricky. But it has been done.
 

Fision

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Thanks for the link ocnorb! Also a very informative write up. For some reason I couldn’t get the pics up, but prob something I’m doing wrong.
Y’all are solidifying my inclination to go air-water. I’m glad to know it’s been done on our trucks with good results.
I believe each of the previously posted threads cover the same kit (DIY 600hp kit) from Frozen Boost. As reported It does seem like a larger CAC or “radiator” (or both) is needed to get temps closer to ambient. Air-water should be more effective than air-air, assuming all is properly sized, designed, etc., and able to cool very close to ambient. Frozen Boost does have a larger system available now and I might try it. Gotta get my engine built first...
 

u2slow

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Is there really not enough room for the usual air/air CAC? (assuming the 'square' radiator vs the wide rectangle)

When I had my '95 F350, it seemed to me a 2" body lift (custom of course) and moving the batteries out would open up all kinds of space for a number of things.... intercooler, exhaust, transmission re & re, etc.
 

Fision

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Is there really not enough room for the usual air/air CAC? (assuming the 'square' radiator vs the wide rectangle)

When I had my '95 F350, it seemed to me a 2" body lift (custom of course) and moving the batteries out would open up all kinds of space for a number of things.... intercooler, exhaust, transmission re & re, etc.
There are a number of examples of air-air installs, so it definitely can be done. Air-water seems the best way to meet the objectives of minimal pressure drop and maximum heat removal. You do have to deal with two separate heat exchangers to get the job done, plus a pump. But each of those components can be smaller. And its easier to snake ~3/4” flexible lines Past the core support, as opposed to ~3+” pipe.
 
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