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Discussion Starter · #1 ·
Ok, so I’m new here but have been around this site for a while ,
I have a 1995 land cruiser with a 4BTA the aftercooler routing is setup strange , I picked this project up from someone else . One of the lines from the aftercooler comes out under cylinder 1 next to the T stat housing and routes up to the aftercooler , the issue I’m having is the way it’s routed it touches the exhaust manifold and is melting the hose, does anyone have a diagram or pictures or info on how I can reroute or fix this issue , I can’t come straight out because the AC compressor and the alternator are mounted next to it . Excuse my poor drawing but the pictures should explain, also the diagram shows the 90* bend that I’m working with . I’m tempted to try and intercooler it and scrap this stupid aftercooler setup.
 

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I'll see if I can help. First off, the plumbing for the aftercooler coolant is metal piping, not rubber. See diagram below. Whether or not they will fit with you custom ac bracket is unknown. Here is another photo from the top. Here is a list of the stock parts and prices from the Cummins store. If those hose parts seem expensive that is because they are high grade silicone rubber.
1 5337075 Hose coupling (old number 3907167) $29.10
2 3914855 Aftercooler tube $73.40
3 3937613 Hose clamp 5 required (old number3918163) $4.83 each
4 3918611 Hose $16.57
5 3918608 Hose elbow $40.35
6 3928909 Hose elbow $45.96
7 3937613 Hose clamp (old number 3934496) $4.83
Human body Gesture Font Auto part Circle

And in the head diagram you'd need part #1 which is 3905639 which is $160.48. That part press fits into a space which normally has a freeze plug.
Font Engineering Gas Cylinder Auto part

You may shop and find better prices. Cummins is never cheap.
 

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Apart from being a little messy you could add a couple of elbows to get it further away from the manifold or go under the engine and back up the other side.
 

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Parts can be found a lot cheaper than the Cummins store prices I posted. For example, part #2 3914855 is on Amazon for $25 Amazon.com: Aftercooler Tube 3914855 for cummins diesel engine : Automotive On part #6 3928909 I didn't find many sources cheaper unless you go overseas. You might contact this one in China. They show it but no pricing. Most of the US sources are in the $45 range. https://www.cumminssale.com/?s=ETFH004 Sort of depends on how quick you need it. That hose part was also used on 6bt engines and even larger models with the aftercooler. Komatsu industrial would have it since they often used Cummins engines but doubt they would be very cheap.
 

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Discussion Starter · #7 ·
thank you. I called my local dealer to see if they can get a hold of those parts , definitely not going to be cheap , but I would rather fix a few hoses than to have to get rid of the aftercooler. I personally am happy with the aftercooler even though I know the intercooler has its benefits.. ordering overseas will be the last resort , especially with everything getting stuck in ports. I’m surprised these parts aren’t more available considering how much these engines are used ,
 

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Well, the aftercooler on the 4bt and 6bt had fairly limited use. On a 4bt you only gained 15 HP and the aftercooler and related part could add a lot to the cost of the engine. It showed up more in industrial engines than road models. You could go to the local Onan dealer and probably find those parts since the were found on generators. Of course Onan is owned by a little company named Cummins. LOL. In reality, the water/air aftercooler is more efficient at removing heat than the air/air intercooler. The intercooler is just a heck of a lot cheaper. All the latest model Ford diesels use water/air type. The big secret that Cummins didn't use is having a separate radiator system for the aftercooler. On the Fords, the secondary radiator is larger than the main one for the engine. That sucker is over 4 feet wide. If you had room in front of your engine radiator to put one that large or larger and run a secondary circulating pump then it could be better. There are also 2 different models of the aftercoolers for the 4bt. Yours is the one we'd commonly see on the CPL 0857 that came in road vehicles. Below is the diagram of a better unit used on industrial engine. That one used the HX30W turbo instead of the H1C on the road engines. Although I've never seen one used, there is even an intake heater for the aftercoolers shown in the second diagram.
 

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Discussion Starter · #9 ·
Thank you for the knowledge! Out of curiosity I know it’s been spoken about a ton already but, how is the aftercooler more efficient than the intercooler when the aftercooler only cools the air to what the engine/coolant are running @ 180-200? When an intercooler is getting ambient air ? That’s the only thing I’m struggling with , I’m about to add an egt/boost gauge because I’m concerned that with my new larger injectors / modified VE that the aftercooler will struggle to keep up . Again, I really appreciate all the help I’ve gotten so quickly !
 

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From my reading on the water/air units, the water absorbs the heat quicker than air so it removes it faster. The Cummins system using engine coolant is not the best idea. In theory you only get down to what engine coolant temp is. The secret of the water/air is to have a separate radiator about as big or bigger than the engine one and a separate circulating pump. As for your concerns about the stock Cummins aftercooler, it isn't the best of units. Most water/air systems have a better heat transfer unit than that one, but that one was fine for its original purpose. There are many aftermarket water/air heat exchangers that are far superior to that unit. You can see why most go with air/air intercoolers. Doing the water/air tends to be much more expensive when done correctly and a bit more complicated. The Cummins version was the cheaper way out and it wasn't cheap. You definitely need boost and egt gauges. Those are a pure necessity. Your power plans will kind of dictate what you need to do for air cooling.
 

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Discussion Starter · #12 ·
I’m going to see where I’m at after I install my gauges in the next week or two, I’m completely happy with the power I’m getting now so hopefully they won’t be too bad to where I need to switch to and intercooler.
 

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Right on! Looking good! I was considering doing an 80 series swap but the price of a clean 80 is just nuts. Plus with a growing family a 1/2 ton American suv was a more practical choice.
Curious what your 80 weights with the 4bt?
 

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Looks good!

Just recently had friend helping with my build mention that could just get some rubber hoses for intercooler and plumbing and thought this seemed odd since every picture have seen they use metal and silicone. Now I see why.

Also, really started getting interested in going with an air/water setup myself since I saw a guy with a similar vehicle as me that went that route and it fit really well too. However, eventually realized there are a ton of websites selling this identical air/water intercooler kit, which guy with similar vehicle used, but after looking into it just did not sound like a very reliable system especially for something you are going to drive frequently or longer distances. Then when I tried to piece together an actual name brand air/water setup its jumps up in price drastically compared to that other kit which was around $500 for everything. Whereas the actual name brand options as char1355 mentioned are quite expensive, for just the air/water intercooler itself starts around $900+ and by time piece entire setup together looking at a hefty cost. Thus, I figured it just be simpler and less that could go wrong by just going with basic air/air setup but sometime in the future would love to try one of those air/water setups. Not to mention can use the air/water ice box reservoir to keep some beers cold if stuck in dire situation lol.
 

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Doc, that's the way is with most people. A good water/air system can be done but it won't be cheap. The Cummins 4bt units were OK but there have been major improvements over the years, Have to remember that design is over 30 years old. The one used in the Ford diesel pickups is vastly better and there are aftermarket replacement parts that even improve that one. It's all a matter of how much power you plan to make and how much money you're willing to spend. Some of the upgrade kits for the Ford run over $5000. Of course when your dealing with an $80,000 or more pickup that might seem small.
 

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Very true Dougal. You only need 2 basic components. A secondary radiator and a circulating pump. The rest is just plumbing. On the Ford trucks they have a second belt driven water pump for that purpose. The electric pump used on the Ford Mustang Cobra is one commonly used for swaps. The radiator will just be how big can you fit in the vehicle.
 
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