Have you checked out frozenboost.com ? they have a lot interesting things going on for air-water aftercoolers...

 

I just looked now and the kit for the 350 hp has a intercooler that looks exactly like mine. Their radiator looks to be twice the size of mine. So it may be that I’m undersized in that area. I wish I had known about them before, I would have just bought that complete kit. I may still buy the radiator although I’m tight for space.

 

As a thought, these may help get additional cooling capacity in a tight space 10'', 14'', 17'', 20'' or 25'' Single Pass Clear Anodized Heat Sink Coolers . You could mount that along the chassis rail and plumb it so that the coolant goes through that before the radiator.

 

If you look at the late model Ford diesels that use water to air intercoolers, the radiator for those is huge. It's core is like 40"x 21"x1.75" and those engines are in the 475 HP range. That intercooler radiator is literally bigger than the engine cooling radiator. And there are aftermarket upgrades that are even bigger. Mostly in thickness and cooling tube area. That is one area of cooling on a diesel where there is no such thing as too much.

 

Up date,

So I decided to do some testing on my intercooler in effort to lower EGTs. First I drove down a local road to get a baseline EGT. I was going about 60 mph and the EGT went to around 1000 for a short time and then slowly backed off to about 900. I did this with a cold truck. The course was 1 mile of dirt road at 30 mph and 3 miles out and back on a two lane black top. When I turned around and excellerated, it went back up to a 1000 and then down again as I just cruised. It never went below 800 and the water temp was up to 210 at the end of the run.

I removed the cork gasket in my intake system. I feel that cork is not appropriate, but the gasket looked fine and I don’t believe it was leaking any boost.

I made a new gasket from that blue material you see.

Next I cleaned out a five gallon bucket and drilled a couple holes. That and some heater hose gave me my test kit.

I had installed some cut offs on the intercooler set up last time I worked on it. They made it easy to do this without draining the whole radiator.

Then it was a simple job to unhook the hose from the suction side and return side of the pump and plumb the five gallon bucket in and separating the whole system from the radiator. This picture shows the setup in the back of the truck.

Obviously, I spilled a ton of water getting the system primed and pumping. I also got a mouth ful of coolant. I can say I would rather drink gas than coolant. This was very difficult and I wonder if it was ever primed before. That pump loses its prime in a NY minute.

On to the test. Again, the truck was dead cold and the temp outside was pretty close to the same as the baseline. I put about 4-5 gallons in the bucket. I drove down the dirt road slow so I didn’t upset the unsecured bucket. At the end I stopped and checked that it was fine.

I headed out on the black top briskly to 60 mph. The EGT went to 1000 again at 17-18 inches of boost. I stumped the pedal for a brief period and got the EGT up to 1300. Let it slow back to 60 and the temp went back to 800-900 just as before. I turned around and repeated the return trip. When I got back to the dirt road I noted the water temp was 200-210.

Before driving back the mile to my house, I climbed in the bed and felt the bucket. To my surprise, it was hot as hell. I’m not saying you couldn’t touch it, but you weren’t going to lift the bucket with your wrists “Kung Fu” style. (for You young kids that don’t know what that means, it was hot) I crawled under the truck and felt the intercooler radiator. It was blowing warm air out. I drove back to the house and got the lazar temp gun out. The bucket was 120 degrees, but it felt like it cooled some from earlier. (Not any boost heat on the dirt road)

So now what to make of this?

 

I have a couple of observations from my air to air setup, in the winter when it's in the teens/twenty's under low loading with the heater on the thermostat almost never opens fully for me. However when pulling a interstate grade at speed my coolant temp will quickly reach 210/220 and just bas quickly drop after the crest, that tells me that the amount of heat removed from the charge air and passing through the radiator is substantial for it too affect the coolant temp that quickly.

 

I didn’t realize that much heat was made there. I plan to do a longer test drive. I kind of afraid to just drive a 1/2 hour straight. Maybe the water would start melting the bucket. It would appear that my intercooler radiator is too small. Even so, the EGT went to 1000 when the water must have been cold. That doesn’t really make sense. I’ve heard that it’s not hot unless you see black smoke. My exhaust comes out high on the pax side. My pax mirror looks right at it. The only time it is a little black is when I’m right on the floor and the EGT says 13-1400.

 

1,000* pre turbo under acceleration is OK and 700* +/- 50* cruising on level ground is about right with "bricks" like you and I have...$.02

 

Yes, your EGT is unusually high. 1300-1400 is in the danger zone. 1000 at cruising is way above normal with your low boost level. Several possible causes. One is too much fuel but you're not seeing a black cloud out back all the time so that's not a likely suspect. Second is pump timing is retarded which will create more heat. And third to not enough cooling capacity in the intercooler system which is the prime suspect. When under boost, that air gets very hot very quick. 300-400 deg F are quite possible. When your boost was 17-18 PSI that is about a stock engine level. Engines turned up to around the 200 HP level are going to hit around 30 PSI.

 

More data,

I drove out to the black top. About one mile of dirt. I kept the boost 2 psi or less. I checked the bucket temp with my lazar gun.

79 Degrees. I drove 4 miles at 60 mph. Checked the temp again.
108 Degrees. I drove back the 4 miles. Checked again.
130 Degrees. Repeat the 4 miles.
140 Degrees. Repeat.
148 Degrees. Repeat.
150 Degrees. Repeat.
152 Degrees. At that point, I figured it wasn’t going significantly higher, so I drove back to the house. When I got back, I checked one more time and it went down to 133. It seemed like a short time for it to go down that much, but I guess there’s not much heat at low boost. Question for anyone, does a turbo diesel intake manifold ever go in to vacuum? If it did, would the intercooler be getting cold?

As far as this test, funny how the highest temp is about what I figure the cold side of my radiator. It would seem that both my intercooler and it’s radiator need to be bigger. The IC I have is taking heat out, but not enough to effect the EGT. The very first run when it was 79 had just slightly lower EGTs. After that, they were pretty constant.

 

diesel motors do not create vacuum as they have no throttle valve... rpm and hp and controlled by the amount of fuel injected into the cylinder... the turbo charged diesel motor is a marvel and is the most efficient internal combustion motor ever created... imo 😁

 

In your driving test, you see the water temperature in the bucket slowly rising. Now imagine that if you had that much coolant in a radiator to cool it down it might never rise much over 100 deg or even less. The trick is you want the intake air to be cool but the engine coolant temp not too cold. The 4bt that had the water aftercooler used engine coolant which limited the cooling ability. Newer engines use two separate radiators and cooling systems. This is often a problem when fitting a system to an older vehicle in trying to find room for 2 radiators. Also, with water to air unit the efficiency of the heat exchange unit can vary by design. Many of the aftermarket units are designed for gas engine applications where boost level is much lower. They often rate them on HP which doesn't really tell you anything. Need to know how much heat they extract. You're taking a good scientific approach to see where you problem area is.

 

It seems truly load based for me around town and on trails I spend a lot of time below 1,500rpm and making 6-12 psi and will see 900*/1,000* and a slight haze.
AT 65mph on level ground it will be turning 1,800rpm and I will see 22/25 psi and 800* +/- 25* pushing my rig beyond 65 requires a lot more running 75mph is 2,150rpm and requires 25/30psi resulting in 950* EGT's +/- 50, and I pay a 2mpg surcharge for that 10mph.

 

At 1800 RPM you engine is at it's peak torque and running very efficient so your EGT is lower.

 

I wonder if that’s my problem. I’m running 2260 rpm at 60 mph. I realize that is not the most efficient, but I don’t understand why it would make higher EGTs. Everything I’ve read says high EGTs are often from lugging the engine.

 

Just thinking out loud but 2260 at 60mph is way too high IMHO, I would expect that you are taxing both your cooling system as well as your charge air cooling and with them tied together they are compounding the issue...$.02

Don’t have much choice. I’m running 4.88 gears. When I first built the truck, it had 3.73 gears and it would not climb a steep hill. (The torque converter would slip) if 2260 is too high, why does anybody put in higher rpm gov springs?

 

I will rev to 2,500 now and then in 1st through 3rd but not in direct 2,250 is about it and in OD 2,350/2,400 is about where the wind wins but that is north of 85mph so...
The stock spring is a 2,500 spring but de-fueling starts closer to 2,300 so the 3,200 spring helps there for me. I know very little about autos behind the 4BT
but IMHO a 4BT with a hx30 and decent charge air cooling should move your rig in top gear below 2,000 rpm. A 4bt with a VE/he221 did fine in my truck geared like that.
I'm puzzled IIRC you are using engine coolant from the post radiator port on the block so you only run one pump, then it passes through the small radiator to the heat exchanger and back to engine radiators inlet. If this is so then a larger secondary radiator might help but still be less that ideal I think, so a stand alone charge air system might be called for.
Does your trans mission have it's own cooler or is it's heat load also shared by the engine radiator?

 

RPM's too high...doubtful lugging is in the equation.

That was my point.

Get a low stall -400rpm torque converter, as for the converter slip on hills, the clamping force is too low or the converter is going south.

The Torque converter is brand new and specifically for a diesel.

 

The Torque converter is brand new and specifically for a diesel.

"Specifically for a diesel"...is a broad statement, since stock stall is generally above the diesels peak torque rpm, higher stall is generally for diesel hot rods, and low stall is below the diesels peak torque rpm engaging below the diesels peak torque rpm...
Your converter maybe "brand new" however, you mentioned it slips on hills, or is it the trans slipping?

 

So I got my temp probe setup.

The instructions are typical Chinese BS. Add the fact they are using this for a bar-b-que and I can’t make heads or tails of them. The small box has sockets for the probes and if you plug one in and turn it on, you get temps. The large box connects wirelessly and when you turn it on and start punching buttons, you eventually get the same readings as on the small box. It’s very hit or miss.

First I attached two probes to the air inlet and outlet of the intercooler. Then I attached one probe to the cold water side of the radiator. I attached the final probe to the water inlet side of the intercooler.

I was thinking that the under hood temperatures might be skewing the readings, so I put some insulation over the probes.

Closed the cover with the small box outside.

Funny how the readings were slightly different when the truck was stone cold. Turned on the wireless box up by my front seat and it appears to work.

Took it out for my 4 mile test run. Right away I started having problems. The wireless part wouldn’t work in the cab rolling down the road. I figured maybe the cab was acting as a fare day cage. (Kind of nice) So I removed the rear window/hatch.

You would think it could work with that hole, but no luck.

So I made another run and got out and ran back to just see what the readings were on the small box. It appears that when the water temp on my dash gauge says 185, the outlet temp on the rad is 170 and the inlet temp at the intercooler is 155. At the same time, my air inlet temp on the intercooler is 178 and the outlet is 165.

Not very impressive numbers. I will say that when it’s idling, they are all coming down rapidly. I would really like some “real time” readings. Im going to have to get someone to ride in the back and record the temps. My Son in law is coming over later today to install a lift kit on his truck. I will probably take him for a ride.

Side note, that’s the first time I have driven 60 mph with the back window/hatch removed. Can you say loud?

 

Ok, I forgot to post this on this site.

I finally got my son in law to ride in the back and take pics of the temp box at speed. It was very interesting.

First, the air going into the intercooler was as high as 276. That was at about 15-17 psi boost. I guess that’s about in line with what people were telling me on here.

The real shocker, the water going into the intercooler was hotter than the water going out of the cold side of the motor rad. This would mean it heated up in the IC rad. Obviously, that could not be. After much head scratching, I figured out the engine drivin water pump will over power the IC pump at high rpms. This causes the water to be drivin backwards through the IC. That means I was getting the hot side of the motor water to the IC. Lol.

Thats not quite as bad as it sounds because the hot side of the motor is still cooler than the 276 of the air, but no wonder I wasn’t getting much help from the IC.

Right now I’ve rigged the 5 gallon bucket back up separate of the motor and I’m going to drive it like that until I get a better setup. It’s kind of tough to to do experiments now because we got a cool spell here now.

 

I have been mulling around your chassis being exposed, and think you would be better off placing inexpensive covers attached to chassis rails over most everything, if done right, it will reduce some of that drag and tweaked to allow for better cooling too.

 

Slight update. I’ve been running the 5 gallon bucket for the last few days while I build a dedicated resivour. The bucket is not much help for EGTs, but I notice that my engine water temp seems to be running cooler. Now I wonder if the hot water running backwards through the intercooler was short cutting the main radiator, sending hot water back to the engine. I guessing the engine water pump was over powering the IC pump around 2100 rpm. Below that, it worked as designed. That’s why it seemed like the minute I slowed down, the engine cooled off quick.

I was thinking it was an aero-dynamic problem above 50 mph. Lol. Of course, this is only a theory right now.

 

Just a thought but with the second pump in the circuit I wonder if it's "suction" is affecting the balance of your whole cooling system now?
I would isolate the IC circuit and see how that changes things, if you now plan for a separate reservoir for it no reason to have them connected...$.02.

 

Trying to get my head around the backward flow situation. The OEM Cummins aftercooler doesn't suffer from that issue. As far as I know there is no check valve in the system to prevent it so its flow loop must work. Cummins uses the same basic flow loop for air compressors on the engines and they don't flow backward. Where are the exact points on the engine where your flow path originates and ends? If your cold side is on the output side of the water pump there is no way its going to flow backward against that pump. The two flow points after the coolant is heated are either on the head on the passenger's side, rear side of the head on the driver's side, or back of the block just below the head. Your cold origin point must be on the cold outlet side of the water pump. One thing that gets in the way on your setup is the thermostat. Until it opens, the heated coolant can't flow back to the radiator. It keeps circulating inside the engine until that opens and lets the hot water out which should occur around 160 deg F. This is assuming your thermostat is working correctly. Until that happens there could be no low cooling point in the aftercooler or engine. This is one of the drawbacks of not having 2 independent cooling systems. On your testing, do you have the ability to check the temp of the cooled water entering the engine?

 

I suspect, "DRAG" starts around 40 to 45 MPH on your rig, using what I like to call the brick theory...under body panels can reduce it some.

 

Trying to get my head around the backward flow situation. The OEM Cummins aftercooler doesn't suffer from that issue. As far as I know there is no check valve in the system to prevent it so its flow loop must work. Cummins uses the same basic flow loop for air compressors on the engines and they don't flow backward. Where are the exact points on the engine where your flow path originates and ends? If your cold side is on the output side of the water pump there is no way its going to flow backward against that pump. The two flow points after the coolant is heated are either on the head on the passenger's side, rear side of the head on the driver's side, or back of the block just below the head. Your cold origin point must be on the cold outlet side of the water pump. One thing that gets in the way on your setup is the thermostat. Until it opens, the heated coolant can't flow back to the radiator. It keeps circulating inside the engine until that opens and lets the hot water out which should occur around 160 deg F. This is assuming your thermostat is working correctly. Until that happens there could be no low cooling point in the aftercooler or engine. This is one of the drawbacks of not having 2 independent cooling systems. On your testing, do you have the ability to check the temp of the cooled water entering the engine?

Charley, I was not using the ports you told me about. (Obviously, I should have) What I did was weld threaded bungs on the stainless hardline that went from my rad to the engine. If you look in this pic on the right, you can see the port on the stainless rad tube. (Below the 3” intake tube) There’s a plug in it here.

Just a thought but with the second pump in the circuit I wonder if it's "suction" is affecting the balance of your whole cooling system now?
I would isolate the IC circuit and see how that changes things, if you now plan for a separate reservoir for it no reason to have them connected...$.02.

The IC system is separate now and is going to remain that way. I’m in the process of removing the 5 gallon bucket and replace ing it with a smaller resivour.

I suspect, "DRAG" starts around 40 to 45 MPH on your rig, using what I like to call the brick theory...under body panels can reduce it some.

Yea, when I made a trip at about 50 mph, my mpg was above 15. At 60-62 mph, I get just under 14. So either the engine doesn’t like the high rpm or the drag gets serious.

 

I finished the IC resivour mount.

Resivour mounted and plumbed. Not sure if the sight glass is a good idea, but I can plug the openings if it gives me trouble. The heat shield is probably not needed, but the hoses are kind of close to the turbo/exhaust and I had it on hand.

I turned on the IC pump and I can see the flow through the cap.

Again this is not going to help with temps, but it gets rid of the 5 gallon bucket in the bed. I’m scoping out bigger IC rad locations. It appears I can only fit a 12” width, so I will probubly be looking at 12” by 12”. That would be twice the size of the current one. I feel like that’s not going to be enough. I guess anything that Is an improvement is better. I could probubly fit a 12” by 14-15” , but not sure if that’s really any benefit because the fan can only be 12” diameter.

 

Yes, your limited space makes things difficult. I wondered whether you could mount a large radiator in the bed behind the cab instead of the large reservoir and have electric fans to cool it. Not all that sure of the vehicle layout. Your fuel milage is not good. Something is amiss there. Even the old delivery vans probably got better than that and they were like driving a cement block. Of course they topped out at 55 MPH. Now high RPM is death on fuel mileage on the 4bt. Once you pass 2000 RPM it can drop like you flushed a toilet. The torque goes down and the HP goes up and fuel mileage goes down. That's 2 negatives and 1 positive. That's why most try to keep the engine speed in the 1700-2000 RPM area. You've just got a unique vehicle that's hard engineer for. Trial and error are the best options.

 

The new reservoir is not large. (As compared to a 5 gallon bucket) Might be a gallon. I haven’t noticed any increase in temps. If I put a radiator behind the cab, I’m sure it could work good. I just don’t want one there. I’m not worried about mileage. It would be nice if it were better, but my main concern is nearly a 1000 EGT in cruise.

I have a larger IC rad coming. We’ll see.

 

New parts in the mail. Here you can see the new intercooler rad next to the old one.

I wanted the new one to fit in place of the old one and even be able to swap back in if needed for some reason. But this little ring for the duct was a PITA to make the first time. So I drilled the rivets out to use in this build.

The cooler will have to be mounted sideways to fit, so the shroud is slightly different.

The mount will use the same holes as the old cooler, but I up sized them to 5/16” from 1/4”. This mount hangs off the back of the T-case crossmember. It’s made from the AR500 I used for the skid plate. PITA to drill and tap, but should be strong enough.

Shroud and cooler on mount.

Hard to take a pic. It blows on the T-case and it’s adapter.

The last thing I did was put a screen on the front of the duct. When I took the old cooler apart, I found a bunch of dragonflys smashed on the cooler. I wonder if they were blocking air flow. At least it proves I’m getting some ram air from the duct. Theair has a straight shot at it, but wasn’t sure if the axle tubes were not disturbing the airflow. If Draggonflys smash on this, I can clean them off easier.

I did a short test of the system while driving to the store to buy some electrical connectors I needed for this installation. (I rigged the connectors for the test) It appeared to lower EGTs by about 50 degrees. Half way there the temps went back up 50 degrees and I was like WTF. I checked underneath at the store and found that my rigged setup fell apart.