Fuel Cooler

[Bdsankey]

I don't agree.

You can monitor temp anywhere. Monitoring before the cooler isn't going to provide a realistic temperature for your bulk fuel or supply fuel temperature. The temp of the fuel in the rail is monitored by the factory temp sensor one located in the return circuit at the rail. Monitoring the fuel temperature post cooler but pre-tank will provide you with the temp decrease across the cooler which "should" be the coolest point in the system given you size the cooler correctly. Monitoring fuel temp (besides the factory sensor) on the supply side post lift pump (if installed) will provide you with the most realistic temperature of the fuel reaching the inlet side of the fuel system IMO for an added sensor.


Where would you monitor temperature with an additional sensor then and why? You have more experience in this subject, but based on what I've seen on my personal truck I have formulated the data above.

 

[Chevy1925]

why monitor what you cant control. monitor what you can control and make it as efficient at possible.

after you have made it as efficient as possible, monitoring the temp becomes irrelevant as it has nothing to do with the computer nor will your right foot control it.

i would want to make the tank as cool as possible. its the largest heat sink and cooler on the truck.

 

[N2BRK]

My MITUSA runs the excess pressure right back into the regulator. I always figured it made the fuel really hot before the cp3. Any concern or should I re-route Opie’s design to return back to the tank?

 

[ZeroGravity58]

why monitor what you cant control. monitor what you can control and make it as efficient at possible.

after you have made it as efficient as possible, monitoring the temp becomes irrelevant as it has nothing to do with the computer nor will your right foot control it.

i would want to make the tank as cool as possible. its the largest heat sink and cooler on the truck.

Where do you get your temps from???

 

[Chevy1925]

Where do you get your temps from???

the factory sensor. all i care about is getting that number as low as possible. it will be the highest temp the fuel will see as well. factory power cutting starts at 230* on my LLY ecm and i could hit higher than that with hot outside temps.

adding the cooler/fan dropped about 20-30* at that same sensor iirc. Lift pump return runs through the cooler as well, that helps cycle tank fuel through the cooler and keep temp down.

best way would be to mount your sensor after the cooler and have one prior to the cooler if you plan to put the cooler on the supply side. if its on the return side, you already have a sensor before the cooler to look at. then look at your readings and see if the cooler is really doing its best for you. monitor what you can control (the cooler and the fan)

 

[ZeroGravity58]

What's confusing me is reading the return temps. Wouldn't the supply temps be more beneficial? Am I missing something? Reason I want to add the guage is I've had problems with p0087 codes on long trips. I suspect it's due to fuel temps and I never really paid attention to my fuel level at that point. I've since added a sump and rerouted a bunch of fuel lines. I also thought about adding a heatsink type cooler outside the frame rail on my lift pump return

 

[Chevy1925]

I doubt that’s the issue. I never had that issue prior to my fuel cooler and I would see temps in the 250* area. That’s summer time pulling hills with dual pumps and the lift pump commanding 26k rail

The biggest gain I saw was mpg while towing.

 

[Bdsankey]

What's confusing me is reading the return temps. Wouldn't the supply temps be more beneficial? Am I missing something? Reason I want to add the guage is I've had problems with p0087 codes on long trips. I suspect it's due to fuel temps and I never really paid attention to my fuel level at that point. I've since added a sump and rerouted a bunch of fuel lines. I also thought about adding a heatsink type cooler outside the frame rail on my lift pump return

I doubt that’s the issue. I never had that issue prior to my fuel cooler and I would see temps in the 250* area. That’s summer time pulling hills with dual pumps and the lift pump commanding 26k rail

The biggest gain I saw was mpg while towing.

Like James said, I don't think that is your major issue. If your truck loses rail pressure due to high fuel temp (as long as its not some insane temperature) then you've got weak components.

What are you seeing for fuel temp when this occurs?

 

[Robby Avery]

My MITUSA runs the excess pressure right back into the regulator. I always figured it made the fuel really hot before the cp3. Any concern or should I re-route Opie’s design to return back to the tank?

Me personally I would reroute it back to the tank the mitusa pump churns a lot of volume and fuel. think of the speed the driven cog is turning in relation to the component that's driving it those two timed mesh gears inside generate a tight tolerance which compresses the fuel and heats it up and the housing is cast so it retianes heat much more than an aluminum housing of other pumps design. I have one that I'm going to use on my son's 89 dodge cummins when he and I start restoring it which I will use in a pusher puller pump configuration to supply the p pump swap we will do :thumb:

 

[N2BRK]

Thanks. I picked up an Air Dog return (cut the filler neck) a year ago when I was thinking about this, but never follows through. I’ll have to put it on the list of round-tuits.

 

[Mike L.]

75F is the ultimate fuel temp for diesel fuel. This came from one of the biggest diesel engine manufacurers. This includes land and marine engines. I will not name the company as I used my friends pin # to get this info. We will not see this temp on our trucks. It is a goal to strive for.

 

[Robby Avery]

Thanks. I picked up an Air Dog return (cut the filler neck) a year ago when I was thinking about this, but never follows through. I’ll have to put it on the list of round-tuits.

If you have a sump that has a return fitting use that instead I've never really like the idea that the fuel has to go up a slope to reach the filler neck just seems like trying to push water up a hill rather than use gravity to feed a water wheel and let it flow smoothly back down the hill just a theory or concept to think about :thumb:

 

[juddski88]

If you have a sump that has a return fitting use that instead I've never really like the idea that the fuel has to go up a slope to reach the filler neck just seems like trying to push water up a hill rather than use gravity to feed a water wheel and let it flow smoothly back down the hill just a theory or concept to think about :thumb:

Just an FYI, this idea negates any heat that could be dissipated in the tank

 

[Robby Avery]

75F is the ultimate fuel temp for diesel fuel. This came from one of the biggest diesel engine manufacurers. This includes land and marine engines. I will not name the company as I used my friends pin # to get this info. We will not see this temp on our trucks. It is a goal to strive for.

You are correct mike for diesel and gas is 95.3F or around about iirc at a perfect stoichometric ratio of 14.7 to 1. Just something to think about when running loaded a air to water fuel cooler would be ideal just a cheap igloo with ice melting and use a drain hole in the bed to feed the moroso fuel cooler that carbed hot rodders use to do and allow it to drip on dry ice that might super cool it but the idea here is bringing down temps. I like the ideas of the Allison 6 speed trans cooler for the air to air setup how would one do that setup with quick connects like factory should I rob trans cooler lines and make hybrid fittings or swap out cooler end fittings for dash an fittings I'm a twin cp3 setup and this has alarmed me to address it so as to not cause a loss of power or longevity

 

[Robby Avery]

Just an FYI, this idea negates any heat that could be dissipated in the tank

Just curious Tim you would rather feed fuel uphill in a return rather than have a smooth transition? enlighten me please the sump would be a direct shot to the tank as a heat sink right?

 

[N2BRK]

I have never needed a draw straw or a sump with my mitusa. I’m thinking if you’re returning at the sump and then drawing at the sump, aren’t you pulling back some of what you just returned? Putting it in at the filler tube would allow it to mix with cool tank fuel long before it’s sucked back up.

 

[Chevy1925]

If the cooler is on the return side, heat back into the pickup is a non issue.

If the cooler is on the pickup side, what ever little extra heat was drawn into the pickup will be quickly wicked away at the cooler as the efficiency of the cooler should be well overcoming the amount of heat being put back into the tank.

Otherwise in either case, you never cooled your fuel.

 

[Bdsankey]

Just an FYI, this idea negates any heat that could be dissipated in the tank

To an extent. A sump with a return pipe to move the return higher into the tank will likely not have this issue. A sump with both ports next to each other will 100% have this problem as fuel will return and be immediately sucked back down into the suction line. I am curious what the fuel flow path inside the tank looks like with a sump that is both a feed and return.

 

[ShopSpecialties]

What's confusing me is reading the return temps. Wouldn't the supply temps be more beneficial? Am I missing something? Reason I want to add the guage is I've had problems with p0087 codes on long trips. I suspect it's due to fuel temps and I never really paid attention to my fuel level at that point. I've since added a sump and rerouted a bunch of fuel lines. I also thought about adding a heatsink type cooler outside the frame rail on my lift pump return

The high fuel temps could be the result of your injectors returning to much fuel which is the reason you get p0087. The hotter the fuel gets the worse the symptoms.

 

[juddski88]

Just curious Tim you would rather feed fuel uphill in a return rather than have a smooth transition? enlighten me please the sump would be a direct shot to the tank as a heat sink right?

If you physically take the return fitting off the cooler or the bulkhead on the tank while it's running (especially with bigger pumps and injectors) you'll see why I'm not concerned with that. If you are returning into the sump, either by itself or into the supply sump, you are working against the head pressure of the fuel. Not to mention that you are just recirculating the same fuel right back to supply suction if it is sharing a sump.