Anyone Install a Fuel Cooler?

This is the problem, people just don't understand the "hot fuel" issue at all. Yes it matters when buying the fuel, but after you've bought the fuel the total BTU content does not change. If the fuel expands 1%, the BTU density drops 1%, but you still have the exact same amount of BTU's in the fuel. That's science/physics.

My point is after you've bought the fuel, cooling it does not change the BTU content. Period. Adding coolers to alter that is just a fools game.

That being said there may be some benefits to cooling the fuel in very specific cases, but these cases are the exception not the rule. I'd say less than 1% of trucks on the road today would benefit from a fuel cooler. And it wouldn't be fuel mileage.

I could see it benefitting a mechanical engine where there's no fuel temperature compensation. But the benefit would be very small, and no different than "turning it up" 1%.

Or on an engine with the "fuel temperature sensor" mod. Trick the computer into thinking the fuel is hot, while keeping it as cool as possible. You might get 1-2% more power doing that at most.

 

Fuel cooler has been on my "to do" list, have been gathering info for awhile, hoping to do it where it will benefit the most. Couple of points to make;
(1) Three different techs have advised to do so- these are local guys, VERY Cat savvy, all gave the same reason, hot fuel will shorten Cat injector life- the performance gain is a plus. They also agree on the cooler being on the return side, IF mounted where good air flow is available.

(2) Best air flow naturally being in front of the radiator makes me think that reversing the direction of fuel flow to the injectors would make this a pretty neat job on a C-15 equipped truck. Someone had posted the fuel flow reversal thing on You Tube, and IIRC couple of guys here had done it.

(3) If someone were to use an automotive tranny cooler, I think care should be taken to use one with large enough tube size; I wouldn't use smaller than 1/2", and that may not be large enough- Cats circulate a lot of gph!

(4) An alternative to the thermostat equipped cooler is to use a three way valve at the cooler inlet; this would allow you to direct fuel flow thru the cooler, or bypass it. Ohio Valve Co is one manufacturer of such a valve, available in stainless and 3/4".

No matter how and where a cooler is mounted, I really think that with todays hotter running engines, a fuel cooler is money well spent.

 

You're the one that doesn't understand. You just stated that as the fuel heats up it loses 1% of BTU's per gallon - common sense tells a person if a gallon of fuel as it expands has less BTU content per gallon that it's going to take MORE of it to get the SAME power out of the motor. That's why ECM's compensate for hot fuel. That's why my CAT with a fuel temp mod runs like a raped ape when I start it up after it's been cold overnight for about 30 minutes until the fuel heats up.. and then you can feel a noticeable loss from hotter fuel with less energy content.

 

Does anybody make a direct bolt on fuel cooler with the right size tubes and fittings for what we need?

 

buddy of mine got his a kw dealer trans cooler think around $150.00 came with mounting brackets and fittings now mine im cheap i took mine off a wrecked truck for a couple bucks

 

Again you're missing the boat. That fuel has also expanded 1%. The total BTU content in the tanks is the same. And again the engine compensates for this. Your cold cat running good is also because the engine is cold. You do not "gain" BTU's by cooling off the fuel, only BTU density, and very slight at that. If you want to gain 1% HP by cooling the fuel and doing the wire trick that's fine by me. But you're also putting 1% more fuel into the engine. You certainly aren't gaining any MPG doing this.

Your engine runs snappier when it's cold because it's cold. The CAC hasn't warmed up, etc.. So it's able to gulp more air easily. Our diesels are also more efficient and make more power when it's cold out, because you have more air per unit of fuel.

On top of this, how does the fuel get to the injector? Through the head, don't you think the head is going to heat up the fuel massively? I'll bet adding a cooler makes very little difference to the actual temperature at the injector.

If it's the cats ### why don't any OEMs have fuel coolers? I've never seen one. Yet every truck I've owned has had fuel heaters. Current truck has a Davco coolant heated fuel filter:

http://www.davco.com/DFP-_fp382.htm

Previous truck had a 12V element in the primary fuel filter.

My point is that there's better ways to improve the efficiency and power of our engines. This is just about the most time consuming and least rewarding "mod" I can think of. A lot of the discussion here is reaching for things that just aren't there.

Fuel injectors are primarily cooled by coolant.

 

Many Kenworths DO in fact have fuel coolers from the factory - unfortunatley mine doesn't. It is an extra option on any truck a person wants - it doesn;t just come that way from the factory (they try to be competitive and keep costs down) but if a person wants one they can spec it. The reason your "logic" is wrong is from your own lips. I only use your 1% number because I don;t know what the actual number is but I do know that if a person heats up 1 gallon of diesel fuel it will expand by a certain amount. Just for the sake of discussion lets say we take a gallon of diesel at 60* F and warm it up to 100* F so now what we have at 100*F is 1.05 gallons of diesel fuel instead of 1 gallon. Are you with me so far? So that 1% loss of BTU's left the original 1 gallon of diesel and is now in the .05 part of it at 100*. You said it yourself, "it only loses about 1%", well Einstein if a gallon loses some of it's punch (BTU's) then it obviously is not going to be as efficient and it HAS to go somewhere, do you think that might be where the .05 gallon comes into the picture. Common sense, logic, and science is with me - it will take MORE fuel at 100* F to get those 550 horses out of my motor pushing me down the road than it will at 60* F. Denser cooler = better fuel. Hot expanded fuel spreads the BTU's out and makes it have less energy per gallon, less efficient - comprende?

 

That is precisely why the fuel wire works so well. Trick the computer into thinking the fuel is warm, therefore it will inject more each time. However the fuel is actually cold, the power difference is huge. allan5oh, I don't know what you drive, but if it is a cat, you would do well to try the fuel temp wire out this winter, especially being from Winnipeg. Then perhaps you will understand.

 

Its not less efficient. That's what you seem to not understand. It still takes the same amount of BTU to go down the road. Cool fuel does *NOT* make the engine more efficient. You still have the same amount of BTU's available.

If you cooled off the fuel, then measured it, then ran it through the engine yes it would appear to be more efficient. But we don't measure fuel at the engine, we measure it at the pump. How much it expands and contracts between fuel ups is actually irrelevant, because the amount of BTU's hasn't changed.

If density increases 1%, you now have 99 gallons instead of 100. Your BSFC drops 1%, but you have 1% less fuel to burn. You're not magically creating BTU's anywhere here.

 

I agree you will get more horsepower. No argument whatsoever from me. But that's simply because it's injecting more fuel. Nothing more nothing less. I'd rather focus on making my engine actually more efficient then just throwing more fuel down its throat.

An aftermarket ECU makes the "fuel temp sensor" mod irrelevant anyways.