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Diesel Fuel Preheating

From the preheating threads and Squirrl22's reply in the engine mod thread got me searching.

Quote:

Originally Posted by squirrl22 (Post 531834)

I modded the fuel injection on my 1986 1.6 IDI VW diesel - pretty easy to do - just advanced the timing, modified the Fuel injection governor so that it no longer limits the fuel over 3000 RPM, installed new, more precise Bosio fuel injectors- Also wrapped electrical heating element around injection lines- preheats fuel to abt 180F -hot fuel atomizes better, runs better esp when engine is warming up. Also inflated the tires to max sidewall PSI, dropped the suspension by 1 1/2 inches w some GTI springs and Bilstein shocks to improve handling and reduce air resistance over 55mph. Bumped my MPG from 44 to 60. (at a steady60MPH), bumped my top speed from 82 to 107MPH, improved my acceleration-still not quick, but at least I can keep up with traffic now.

I found this from VWRacer

Quote:

Originally Posted by http://vwdiesel.net/forum/index.php/topic,738.0.html

All you guys up in our Great White North Neighbor can probably benefit from somewhat heated fuel. Diesel fuel ranges from a carbon number of C9 to C23, centered on C16 (gasoline ranges from C3-C10, centered on C8 ). All hydrocarbons solidify at a rate proporsional to their carbon number, with the higher diesel compounds solidifying (freezing) as high as 15C (60F). By -5C (~20F) half of diesel compounds are near or below their freezing point, and the fuel can really benefit from external heating.

Conversely, diesel compounds have quite high boiling points, ranging from 175C (~350F) for the lightest compounds to more than 370C (700+F), so even if it's heated to the standard operating temp of a TD (95C or 200F) it is just slightly thinner, but in no danger of boiling. There isn't much change in volume as diesel heats up, so that isn't much of an issue, either. (The coefficient of thermal expansion for diesel is 0.0046 per degree F, so heating a gallon of it from 32F to 212F (0C to 100C) increases its volume to just 1.083 gallons.) Moreover, heated diesel has lower drag in fuel lines and injectors, makes for a better spray pattern, and ignites easier in the cylinder.

In a normally running diesel engine, all the conponents heat up to operating temp eventually, so once the engine is thoroughly warmed up, there is probably little need for additional fuel heating, but it won't hurt any.

I might think about using a counter flow chiller to heat diesel with coolant by installing it between the filter and injector pump. The hard part will be installing a tee in the coolant path to and back for flow.

Has anyone tried some thing like this on a TDI or any other direct injection diesel? Do you see any down sides or issues to look for?

I will need to figure out my transmission issues before I start doing work like this though.

that shows a great deal of promise. I have 3 diesel rigs, and this week I was operating my truck in 5 F temperatures. The fuel and IAT temperatures were far from optimal :(

Cummins marine advises against heating fuel beyond 125°F and actually recommends keeping the fuel close to 75°F to prolong injector pump life and the best fuel economy.
You don't need to heat the fuel since the injectors are screwed into the cylinder head. So by the time the fuel is injected it's already at cylinder head temperature.

I have an artic fox fuel heater to install. I'm going to limit it's temperature to around 100°F.

Ask the svo guys. They are in to fuel heating.

Quote:

Originally Posted by oil pan 4 (Post 532075)

75F is probably a lot easier on my CP3 high pressure pump too. That 5 F stuff has to be hard on a 18,000 PSI pump.

I have a tentative plan for tapping into my heater core coolant hoses, and making a heat exchanger that has about a pint of volume. Get it as close as I can to the engine mounted filter/water separator.
I don't know if my OBDII give me fuel temps or does anything with them, But it seems that 75 F fuel could never hurt, and may help.

The only diesels I know that run fuel that is even kind of heated up are snow cats. They heat the fuel to 120 to 125°F. That's just so the fuel doesn't gel in -40 temperatures with 80mph winds.
But they don't use CP3 pumps.