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Just curious there was such interest in the water coolers from those who have air to air coolers? Air to air intercoolers posses more cooling potential than an air to water. More cooling capacity.....cooler air charge......more available power. Am I missing something.

On another note, if your turbo can push it, what about using a slightly smaller air to air intercooler that feeds into an air to water on top? Some LARGE industrial applications do this (air to air gets the largest temp drop, then the air to water takes it down a few degrees).

Just thinking out loud
 

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the only reason i want the water cooler is because i dont want to cut the rad. core support on my army truck i,am doing a swap in . why would you want to reheat the charge air from a air to air cooler by running it back to the water cooler ? air to air is far more efficient. this is why modern semi trucks run ata coolers .
bob
 

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I know air to air is more effecient. Thats why semis, light duty, etc run them. I was just curious why large equipment would run both. Your engine water temp should be below 200. The air coming out of the air intercooler is hotter than that so by Fourier's Law (law of heat transfer/radiation) which states heat flows into cooler bodies, it will not heat up, the water will take out heat. The amount the water takes out will be not as large though.

Im not knowledgable about the water units, just trying to apply the physics I do know to them.

Do the water intercoolers use a closed circuit of water, or are they connected to the water from the engine and circulated. If it is a closed circuit, then my question is answered as the water will be above engine water temps. If not then hmmmmmmmmmmmm.
 

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That water is much hotter than ambient air, but it is far more thermally conductive, absorbing a lot more heat than the same volume of air. I think the "air to air intercoolers are more efficient than water to air ones" has more to do with the relative size of each one. The water intercoolers I've seen tend to be tiny, compared to huge air to air ones. I bet a similarly sized water intercooler could outperform an air-air one.

I know air to air is more effecient. Thats why semis, light duty, etc run them. I was just curious why large equipment would run both. Your engine water temp should be below 200. The air coming out of the air intercooler is hotter than that so by Fourier's Law (law of heat transfer/radiation) which states heat flows into cooler bodies, it will not heat up, the water will take out heat. The amount the water takes out will be not as large though.
 

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The only reason I use Liquid Aftercoolers rather than CAC is the physical design of Dodge Power Wagons. Its near impossible to run plumbing for a CAC. Liquid Cooled fit beautiful and problem is over.

Paul
 

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The only reason I use Liquid Aftercoolers rather than CAC is the physical design of Dodge Power Wagons. Its near impossible to run plumbing for a CAC. Liquid Cooled fit beautiful and problem is over.

Paul
Exactly, the packaging of an air/water cooler gives you a lot more freedom to fit them in a cramped engine bay.

Running engine coolant in an air/water cooler is easy but not as efficient. The best way is to set up a seperate circuit with it's own pump, radiator and reservoir.

Radiators that work well are cabin heater radiators, oil coolers and even AC radiators if you can remove the restriction that makes the gas expand.

I made my own air/water system but kept running into walls looking for a good exchanger for the boost/water side. My own devices worked but I couldn't get enough surface area into them.
I looked at running a small intercooler, plating it and welding in some line fittings. But I couldn't find an intercooler which was compact, could handle the flow and had good endtanks. Most of them were odd shapes and many had plastic end tanks.

PWR make some nice looking air/water exchangers with high flow, but they're expensive.
 

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Discussion Starter #9
Thats what I was looking for. Thanks Lee for pointing out the obvious that large stuff doesnt see highway speeds (or parking lot speeds in some cases). And thanks to everyone else for your input as well. Seems there is nothing wrong with the water, just its compact design lends it to cramped engine bays.

I see how the physics does apply and it comes down to design (thats usually the case), since I am not up on the water coolers, I thought I would ask the court.


Thanks all for chasing that rabbit with me!
 

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For those of you that are jumping up & down to put a air/water aftercooler on.. Im running a 4bta with the jwac setup on the intake, my exhaust gas temps went down when I stopped coolant flow through the unit. I intend to try converting to a self contained circulating system, but if this doesnt yield good results I will be going with air/air setup. Hope this helps.
Carl

1979 F-250 crew cab 4 x 4
4 bta
ZF S-42 5 speed
Borg Warner 1356 x-case
Dana 60 rear
Dana 44 front
3.55 gears
255/85R16 tires (33.5x10.5)
Hydroboost steering and brakes
Custom 40 gal. fuel tank
Much more later
 

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small electric water pump

If you are looking for a small electric water pump to circulate the fluid for a air to water cooler then grab one off of a Mercedes 300 diesel.
I know that the 80-85 300 diesel had a small pump located on the passenger fender area that would turn on when you turned on the heater. It may just be the ticket. The junkyards are overflowing with them and they can be had for real cheap. Only 300's diesels had these, not the 190's or 220's or 240's.
 

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I am going to toss in my 2 cents of information. It is my understanding the JWAC was designed to maintain a constant temperature of the air entering the engine from the turbocharger. On the flip side of what everyone is currently looking at is that part of the design is to increase the air temperature entering the engine permitting the engine in a stationary application to decrease warm up time. For example if you have an engine mounted on a wood chipper and it's twenty degrees outside the warm up time to operate the chipper is decreased so productivity of the crew using it increases. So why did the early Fritos vans have the JWAC? I don't know other than the usual unit standardization, availability and price at Cummins verses the demand by Fritos. Remember that this is an industrial designed engine adapted for automotive use.
 

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Cool, thanks Matt for the tip on the water pump. Will definately keep that in mind next time I go scavenging.
You too Bob, I always get a warm, fuzzy feeling when you kinda, sorta, almost agree with me.
Carl
 

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I wonder how long a cheap RV water transfer pump would last?
Carl - I sorta agree, maybe, almost but I'm somewhat not sure.:smile:
 

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This is very interesting and confusing. I have 2, 1999 Recon's CPL 875.
If you look on the data plate its listed as a 4BTA. YEt in the Cummins shop manual it lists a CPL 857 as a 4BT. They both have Liquid/Air aftercoolers.

Were the Liquid Aftercccolers added during Recon thus making them a 4BTA ? Both were out of P-30 Step Vans ? Both these engines are listed as 120 hp at 2500 R's.

Yet the CPL 767 and 1260 engines I have that are CAC out of P-30 Vans are listed in the shop manual as 105 HP at 2500 R's. The CPL 767 is listed as being a 4BT yet the Data Plate says 4BTA. The CPL 1260 is listed as a 4BTA and Data Plate says 4BTA, yet the same 105hp at 2500 R's

Looking at the
 

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Ha, fat finger hit enter by accident.

Yet the shop manual lists CPL's 592 thru 594 as 4BTA's but with low HP, and you dont see HP equal to the CPL 857 until you get way up to CPL 1963 series and 2264. ?

The shop manual does not say which CPL is CAC or Liquid. So wich is Cummins rating the higher HP, CAC or Liquid.

Now I can hit enter ha ha

Paul
 

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I've often thought about dumping my low side A/C through mine. Just a thought thou......Why don't one of you guys try this for me and see if it works. LOL

I've seen school busses with electric aux. water pump to circulate water to the back heater cores.
 

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Subaru fitted water/air intercoolers to some of their legacy/liberty turbo cars.

I have a 12v pump from one of these systems which I used in my experiments. Easy to source wrecker part if your country ever saw these cars sold.

They pull about 5amps and fit 3/4" hose. Small and quiet.
 
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