Fuel .....hot or cold.....

[NTOLERANCE]

... Assuming your fuel system is healthy, and regardless of fuel type (wvo wmo who diesel), regardless of ambient temp, is it better to have heated fuel (sayrun through the trans cooler on a stick truck) or just ambient temp fuel for regular, for light duty use? Can diesel be too hot? I dont see a reason to run cold/cooled fuel in a diesel where as a gasser prefers it.

Thoughts?


And yes iam considering running all my fuel through the trans cooler regardless of fuel type or air temp.

 

[idiabuse]

I started to collect fittings to circulate WMO through the cooler/heater in the radiator. The thinner the WMO the easier it is to pump, less strain on my electric pump, and also it will get hot enough to steam out any water in the system.
I just need a few more fittings and I can get it going soon.
I notice when the temp drops I lose psi and sometimes it will air lock and have to wait for pressure to build.
I also want to heat the tanks or primary fuel filter to get it started on a cold morning, so I am trying to decide wich system to try.


Javier

 

[homelessduck]

My fuel line runs between the intake manifold and valley pan. I'm sure the fuel gets nice and toasty. My truck loves it.

 

[7.3 powerstrok]

yes diesel fuel can be to hot .....as for running it through the trans cooler this will heat the fuel nicely on a 30 degree day ,however on a 100 degree day to hot ....poor performance decreased fuel mpg ,...also the amount of fuel in the tank will impact the temperture of the fuel ..example less fuel in tank higher fuel temp due to less volume for the warm fuel being returned to the tank ,,realy no reason to heat diesel fuel if air temps are above 0 degrees ,with the exception of at engine start -up ,,,also as for wmo the only reason to heat that is to increase the viscosity thus improves flow ,,,some one will chime in and word this better thanks

 

[MUDKICKR]

yes diesel fuel can be to hot .....as for running it through the trans cooler this will heat the fuel nicely on a 30 degree day ,however on a 100 degree day to hot ....poor performance decreased fuel mpg ,...also the amount of fuel in the tank will impact the temperture of the fuel ..example less fuel in tank higher fuel temp due to less volume for the warm fuel being returned to the tank ,,realy no reason to heat diesel fuel if air temps are above 0 degrees ,with the exception of at engine start -up ,,,also as for wmo the only reason to heat that is to increase the viscosity thus improves flow ,,,some one will chime in and word this better thanks

please explain that again? since the radiator is right at 200 degrees (round about) how will it matter if its 100 degrees outside or 0 degrees outside? yes the fuel will be warmer on the 100 degree day going into the radiator, but when the engine is at operating temp the radiator is going to be at the same degrees either way, its going to come out the same temp on either day. if what your explaining is true, then if you turned the heat on in the summer, you would melt everything around the heater core.

 

[rhkcommander]

when the diesel fuel is compressed by the pump, and in the chamber it heats up to burn... Heat makes it flow better too.

 

[7.3 powerstrok]

yes i agree would be the same degrees ,however on a 30 degree day the fuel would have to be retained in the rad longer than on a 100 degree day ..to be at the same temp ,

 

[jaluhn83]

You want the fuel temp to be around 60* for #2. Too cold and it'll gel and be too thick, but if it's hotter, the viscosity will be too low and more importantly the density will decrease, so you'll be effectively delivering less fuel to the injectors. Same reason why the engine runs better on cooler air than hotter.

Also, remember that the dynamic timing is hydraulic controlled using the fuel, and this system is very sensitive to the fuel viscosity. Changing fuels (ie WVO) completely changes the dynamic timing curve, as does too high or low of #2 temp, though not as much.

Bottom line, there's absolutely no reason to go to the trouble, and you'll see a performance decrease.

 

[icanfixall]

In the bottom of the 7.3 psd filter housings is a fuel heater. The 7.3 idi has the heater in the top of the filter head. So why is the fuel heated.. How warm is it being made. BTW the 6.9 fuel heaters are that wide area in the feed line from the lift pump to the fiter head. So for some reason we run a preheated fuel. Still not sure why or if we really need it.

 

[jaluhn83]

The main purpose of that heater is to mitigate gelling in cold conditions. There should be some sort of a thermostat control built into those, though not sure exactly how.

 

[racer30]

If fuel temp and power were a problem then the Detroit 2 cycle engine would not have been such a good engine. the fuel passed throught he cylinder head to reach the injector the fuel was used as cooling for the injector itself. the return line to the fuel tank would bring up the temp of the tank of fuel also. Anyone that drove one would Know not to pull a long mountain pass on low fuel tanks because it would mean high fuel temps and posible engine overheating. The PSD 7.3 runs the fuel through the cylinder head also and I'm sure they run hotter than 200*. I cant see any problem warming the fuel some if you are running WMO or WVO You could try running it through the trans cooler loop and check the performance. The IP will run pretty hot under normal conditions and it uses the fuel for lubricant and cooling so I don't think you will see any change in performance. Just my 2 cents...

 

[jaluhn83]

Different animal. It's not that heating the fuel is inherently bad, it's that you're departing from the system design parameters. Those engines were designed to operate with fuel at xx temp. The IDIs were designed for xx..... not the same thing.

And yes, it is used for pump cooling, good point. So heating it before it gets to the pump means you're not cooling the pump as effectively too.

Don't fix it if it ain't broke. Chances are, yes it'll work fine. *But*, you're not gaining anything, and adding complexity, in addition to making the fuel system works less efficiently even if you don't actually see a macroscopic performance change.

 

[79jasper]

Maybe someone with a quality timing meter can compare timing with a complete stock setup to running a cooler of some sort.
I think it'd be interesting to see.

Also someone with a pop tester could do the same.
Say the 60°F mentioned above vs whatever the fuel return temp is. To compare pressure and spray pattern.

 

[jaluhn83]

From my BMW 524TD manual:

"The electric fuel heater is standard equipment on vehicles equipped with the 2.4L diesel engine..... Power (approximately 200 watts) is available the the fuel heater whenever the key is in the on position, but is used only the fuel is cold. A bimetalic strip is located below the connector and is exposed to diesel fuel.... the snap switch (bimetalic strip) sense fuel temperature and operates within a temperature range between 30 and 55* F. This means that the heater will be operating at a fuel temp of 30*F or lower, and must cease operating at a fuel temperature of 55* or above."

Not quite the same engine, but it uses a similar injection pump (Bosch VE) and illustrates the general concept.

 

[Hope]

Going to throw this out there. Relatively new to the idi but the simple theory is this. A more complete burn with a diesel will involve more oxygen and a hotter fuel mix. Compression of air heats the air fuel mix hot enough to ignite the mixture and fire the piston. Higher temp fuel will require less compression to ignite and will give a more complete chemical break down of the fuel (provided enough O2 is there). I ran a liquid to liquid heat exchanger into my system yesterday. I have a duralift (12-15psi pump, pumps 8 psi on other side of cooler) pump that send fuel through a heat exchanger and then to the fuel filter. The exchanger exchanges with the hot tranny line from the little trans radiator. Effectively heating my fuel to 130-190 F (best guess I don’t have a temp gauge but it’s hot) and cooling my trans oil down more. Truck still runs, and honesty I think runs pretty well. A a really solid shake to the idle after driving around. I’m not mechanic nor pretend to be one haha. So feedback would be nice.
Point of concern: am I going to burn my ip pump. I shouldn’t think a 90 degree difference will actually matter with the pump. It’s designed to handle a lot of heat, even if it’s range, the materials made for that range will likely greatly exceed its working capacity. The only reason I’m concerned is because it’s cooled/lubed by the fuel. Can’t find how that actually works anywhere. Didn’t blow up after 2 hrs on the road at 60. But I’d like more information before making it a permanent addition.
Note: will decrease fuel density a little but will increase efficiency so they counter balance. Truck has run in a while but I’d say the efficiency out weighs the density in terms of power.
Thanks and gig’em