Fuel Cooler?

[lumberjack]

My RG85 is my main grinder and it's powered by a Deutz tubocharged diesel with 2300ish hours on it.

The return fuel is fawkin hot, always has been. I saw a tranny cooler in the shop that's never been used and I considered mounting in front of the radiator to cool the return fuel before going to tank.

I know it's common on other diesels and I can't see a way it'll hurt. Anyone see something I'm missing?

 

[stehansen]

I didn't know it was common to cool the return fuel.

 

[Mr. Sir]

I don't see why that wouldn't work.

 

[lumberjack]

What about the supply, Steve?

I didn't think so, Brett.

The fuel has 3 filters before it gets to the motor. The first is a standard inline filter, the second is a fine mesh strainer and the third is a spin on type. The mesh filter is plastic and looked a little distorted, like it got a bit warm. That's what made me think of a fuel cooler.

 

[Wagnaw]

man you guys are way too mechanically inclined for me....

 

[Jonseredbred]

Whats wrong with having hot fuel??

 

[lumberjack]

If nothing more it cools the engine less. Also the fuel tank is plastic so extra heat isn't that great of a thing. The return line doesn't use clamps, and eventually the rubber degrades and they slip off. Trying to get them back on with the fuel near scalding you is a PITA.

If the engine was computer controlled, most ECU's derate the engine when the fuel gets over 175* or so. Mine isn't computer controlled, but theoretically it should make more power, but that's a non issue to me.

 

[stehansen]

I don't know. This is totally out of my area. I would be interested to know what you find out. Some of the older caterpillar engines used to warm the diesel by running it through the water jacket before it went to the injector pump, but I was told that was for really cold climates and was not needed in California. The old cat system didn't return any fuel either. Deutz has a Bosch system right?

 

[lumberjack]

Newer trucks have fuel coolers, typically. In colder climates they need fuel warmers, like you mention.

I'm not sure what kind of pump it uses, but it's a direct injection setup.

I figure I'll get the engine back together, run it and take a temp reading. If it's reasonable, I won't worry about it

 

[Thor's Hammer]

Newer trucks have fuel coolers because the common rail injection systems run at much higher pressures than th eold systems, as much as 35000psi in some systems.
I guess your climate would contribute to hot fuel, I've run a few duetz motors and never had overheated fuel. I do know that heat affects the viscosity, and therefore the atomisation of the fuel within the combustion chamber, but with the kind of temps your talking about, I cant see it being an issue. How about running a coil of pipe and keeping your coffee pot warm on it?

 

[Dave Shepard]

Cummins CR runs 28,000 psi, The Jeep Liberty CR was 31,000. My Dodge uses a fuel heater, but not a cooler.

 

[sawinredneck]

This is all new to me Carl! I have seen hydraulic coolers and I have seen hydrostat coolers, I have even seen intake air coolers, but never heard of fuel coolers?
IF, you were to do something of this nature, the ONLY way I can see a benifit is to cool the incoming fuel, but with the pressures the pumps put out, it would have to be after the pump and before the injectors. Good luck with those PSI's!!
Cooling the return fuel, well, that is what the fuel tank is for! It goes in, hottest sits on top, coolest on bottom and the pick up is on the bottom.
The theory for no clamps is that it's just going into "empty space", so no real pressure is presented to the lines. And it cools quickly as it expands. Much like an air compressor.

 

[sotc]

Cummins CR runs 28,000 psi, The Jeep Liberty CR was 31,000. My Dodge uses a fuel heater, but not a cooler.

I was thinking around 30000 psi also

 

[Dave Shepard]

Your truck has a VP44 Bosch pump that will make up to 17,600 psi. The injectors have a 4500 psi pop off. Fuel delivery is controlled by injection pressure. On a CR system, fuel delivery is controlled by injection duration, which can be in as many as five times per injection cycle.

 

[NeTree]

Carl, if your return fuel is running that hot, it isn't a fuel cooling issue, it's a cooling issue.

The hotter diesel is, the more efficient it atomizes and burns.