Fuel temperature question

[cranetruck]

It should start to get warm in some of the South/Southwestern states by now and I have a question for you deuce owners in those areas;
How warm does the fuel get in the deuce fuel tank after sitting at idle in the sun for a while? Would you mind grabbing a thermometer and help me find an answer?
This is a standing question with Kenny in Florida, but the more inputs the better.
Even at fairly cool ambients here in Virgina, the temp hit 90F or so in less than an hour. The heat from the returned fuel helps to heat the fuel in the tank.

Thanks,

 

[Polverone]

Bjorn,
Rain here tomorrow but should be able to attempt your experiment on Wednesday - if I see the goldern orb in the sky.

 

[Boatcarpenter]

Bjorn, I realize I'm not in the area you want to study, but I was dubbing at the house today writing estimates, weeding the winter's collection of crap out of my work truck, etc., so I thought I would get you some numbers. I'm curious myself anyway because I would like to come up with a WVO/bio or petrodiesel mix that would work up here through the summer without separate tank, heaters etc.
TIME AMBIENT TEMP FUEL TEMP ENGINE TEMP

11:50 63 50 Cold
12:05 63 54 +/- 120
12:20 67 58 +/- 165
12:35 66 62 +/- 180
12:50 68 67 +/- 180
01:05 75 71 +/- 180

Other considerations:
Grill cover closed
Hood open( doing other stuff on engine)
No agitation in tank other than that from returning fuel
Fuel at start: 7.75 inches=+/-25 Gals.
Fuel at finish: 7.25 inches=+/- 23.4 Gals
Fuel tank not quite level
Approx. 3.22 Gal fuel/in.

Hope this is helpful in some way.

BC
PS> I typed this in nice columns but it got all crunched when I submitted it.

 

[mangus580]

Great info BC! This is the kind of stuff I like to see

 

[cranetruck]

Thanks for the info, BC!

Ambient increased 7 degrees in 15 minutes, you didn't measure the ambient in the sun, did you?

Your numbers pretty much confirm what I have observed here. The amount of fuel in the tank makes a diference when it comes to heating it of course, so recording it is a good piece of information.

One reason I'm curious about the temperature increase without trying to heat the fuel with coolant, is my concern about boiling off methanol in the unwashed biodiesel I'm using. The boiling point for methanol is 148 deg F.
The combined effect of warmed return fuel and the sun is what I'd like to see.

 

[Boatcarpenter]

I had two thermometers, one hanging in the fuel and the other hanging from the truck right near the tank, and yes I think the sun hit the ambient thermo for that reading. Was kind of a spur of the moment experiment and not particularly high-tech. A couple of inexpensive Taylor
thermometers, used the truck temp guage etc.. Nevertheless, it gave me an idea of what was going on. Makes me wonder what the temp of the returning fuel is. Maybe I'll do a little more controlled experimenting as time permits.

 

[cranetruck]

The flow rate of the return fuel was surprisingly (to me anyway) high at 2 quarts/minute at idle and about 3 at 1,400 rpm. When I was messing around with the dual tank project, I had all lines open at one time or another and was able to check these things. The return fuel temp was about 110F at one time with the engine at idle.

The excess fuel is used to cool the injectors, I think.

The in-tank fuel pump pumped at a rate of 6 gallons/minute when I used it to recirculate/filter the fuel at one time (image below).

 

[Boatcarpenter]

Assuming the same rate for my system, the fuel in my tank cycled one and a half times. I would guess then that the temp of the fuel might have been reasonably consistent throughout.

 

[cranetruck]

Any more takers on this "project". Brent and Ken, it gets pretty hot where you are, right?
Next time you leave your truck at idle in the sun, could you please stick a thermometer in the tank and let us know the temp. TIA, I would really appreciate it.

 

[Recovry4x4]

While I don't mind helping out, can't seem to find a decent thermometer for the job. Need one of them DVMs with the thermocoupling

 

[cranetruck]

Oh well, maybe next time I stop by for a visit.

 

[cranetruck]

Checked the fuel temp yesterday. The engine was not and had not been running, but the fuel temperature was 85F with an ambient of 60F. Sun was beaming down on the tank.

 

[Recovry4x4]

Are those no too expensive digital thremometers any good? I need to get to helping Bjorn.

 

[cranetruck]

This is the one I have been using for years, comes with simple thermocouple probe or a universal thermocouple adapter for use with any type K probe.

http://cgi.ebay.com/FLUKE-16-Digita...ryZ25412QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Costs about $100 new.

Thanks for offering to help, Kenny!

 

[Desert Rat]

Bjorn,

Ken and I will be working on 'Storm here in a few weeks. He's got a lazer temp. gun. I'm sure interested in finding out the temp. We'll record our datum (plural for data) and release it to the forum when we finish.

 

[ken]

Bjorn, It gets well over 100deg F here in the summer. I know it takes hours to warm the tank because the tank will sweat from the moisture in the air as it gets next to the cool tank. In the afternoon it shouldn't have a problem getting above 100deg. I can use my heat gun and run a few tests for you. The m35 is in the shade all day but the fuel tank on my M52 is in the afternoon sun. I'll check them when i get home. How many readings do you need? Once or hourly?

 

[cranetruck]

Thanks guys! I'm interested in the maximum fuel temp, with the engine running and when the tank is exposed to the sun.
The return fuel from the engine will help heat the fuel and I would like to know how close to 148F (methanol boiling point) it gets.
So, just one measurement, that's all, but the max reading with the engine at idle or about 1,000 rpm.

TIA

 

[cranetruck]

Ran the deuce for an hour today using the crane.
Ambient: 68F
Fuel temp before starting w/sun hitting tank: 91F
Fuel temp after an hour at 1,000 rpm: 107F
Engine op temp after an hour (radiator cover with flap open): 172F

All temps with digital thermometer including eng op temp.
Fuel tank heating system: OFF

 

[Desert Rat]

Mine is mostly in the shade as well in the afternoon but gets a good mourning wake-up call. Ken, you might want to check out the mourning temps too to see if the difference in the day has a significant impact.

 

[ken]

I got home about 5:30 yesterday and i grabbed my laser gun.
Outside temp was 82deg. The M35 was in the shade all day. I opened the cap and pulled the strainer. I got a temp of 78deg. There is about 30 gallons of 70% diesel and 30% used motor oil in the tank.
The M52 was in the sun all afternoon and had about 25 gallons of diesel in the drivers side tank. It was 92 deg. The pass side tank is empty. (repairing a leak). Both tanks are 383 CARC green. I forgot to check it this morning. I hope this helps.