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PTC Thermistor and Electric Inline Heater.
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<p>That isn't very much heat. The VegTherm (for example) produces over 10 times as much (30 amps @ 12 V)



Yes, but for 150$ US I can buy 50 of the 1 Ohm version, making a 600 Amp (7200W) heater and enough cash for materials and to pay someone to assemble the thing. Yes, I know it is far far away from a good idea. But the point is that you can put many small one in parrallel, making as much heat as you want, and being sure it is well reparted in your heater.
 
Location: Sherbrooke, QC, Canada | Registered: June 26, 2002Reply With QuoteReport This Post
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Location: UK | Registered: May 27, 2001Reply With QuoteReport This Post
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thermisters can be made to any specification,basically. from line heaters to swimming pool heater size. samples suitable for us will soon be on the way to me. i am in discussions with a u.s. manufacturer/ptc fabricator i found about price and quantity. i understand fully how they work, but i need a little help,or else ill just tinker till its right,on the rocket science part, here goes. for wvo, traveling at the rate of 1/2 gal per hour per 1/4 inch line,(4cyl)30mpg, how much heat along how much metal injector line would be needed to raise the fuel temp traveling through it 40-60f. i have some comming that are about 2'' long in an aluminum housing, set for 300f, we will go from there. no, they wont transfer the whole 300f to the lines, maybe 200-250. also available are lengths of heated tubing,immersion heaters,etc. i should have some prices soon.


1983 datsun 720, sd22 "GOIN'ON GREASE"
 
Location: orlando,fla | Registered: December 21, 2003Reply With QuoteReport This Post
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Parts for Building 12v Electrical WVO Heating

Thanks folk for the info. in this thread on the topic.

WVOCARZ
WVOCOLL


_________________________
If you believe you can't YOUR RIGHT;

But equally so.... if you believe you can, YOUR RIGHT as well.
 
Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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Quote " how much heat along how much metal injector line would be needed to raise the fuel temp traveling through it 40-60f "

The short answer is "that depends", long answer is that depends on many things such as ...
Temperature of the inbound fuel. Heat transfer varies dramatically in rate depending on the temperature difference. IIRC it is proportional to the square of the difference.
Specific heat capacity of the fluid. I'm not sure how much variation one will find in oils but this may account for modest differences.
Interface between the two items, steel and oil in this case.
Flow rate, you've got this one already defined too.

I had a moments concern about boiling of water that may sneak through but if it has past the IP you should be clear of danger in that regard. That does seem really hot though, I hope you don't start producing solids inside your injector lines !

Keep us posted, Good luck, Glenn
 
Location: location, location | Registered: August 05, 2002Reply With QuoteReport This Post
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how much heat along how much metal injector line would be needed to raise the fuel temp traveling through it 40-60f


Well.... I'm not sure about this, but a good aproximation could be done by calculating the quantity of SVO passing by your line in a second, then knowing that a Watt is Joules*Seconds, you use the thermal capacity of grease to calculate.... Ok, here's the example:

Whe have a hose with 2L (1/2 Gal) per hour passing through it (I'm not sure it can be true, but heck, it's an example anyway). This means we have 0.5ml/seconds.

Going with the heat capacity of water (4.2[j/(g*°C)]), altrough grease should be lower than that, and assuming the grease has a density of a g per ml (and yes, it still should be lower than that!).

0.5g*4.2= 2.1W/°C raise in a second.

So, to raise the temp by 40°C, you will need 84Watt.

Still, it is true that you will have many many losses. Junction temperature, heat dissipation trough line, etc, etc. If I was you, I would aproxximate how much I need, and put out twice the amount, as a security factor Big Grin. Anyway, the PTCs are self-regulated, so no problem with heating too much.

Have a nice day!
-Jay
 
Location: Sherbrooke, QC, Canada | Registered: June 26, 2002Reply With QuoteReport This Post



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ok, thanks all. the ptcs that are comming in should be around 200 watts, and max out at 300f, allowing for all the variables, this should be about right. the oil in is about 140f, so that should be eneough to raise it to about 200f as it travels through.


1983 datsun 720, sd22 "GOIN'ON GREASE"
 
Location: orlando,fla | Registered: December 21, 2003Reply With QuoteReport This Post
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How are any of you that are looking into the ptc's planning to put them in your fuel lines? it would be nice if we could just find a nice one that would thread right in, but so far, I have found nothing of the sort...

Any ideas would be appreciated!
Thanks!
 
Location: WA | Registered: December 30, 2002Reply With QuoteReport This Post
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everyone discussing heat,except for melting points and filters, like,injection temp heat. feel your metal injector lines. they will be much cooler than your vegtherm or otherwise heated fuel going into the injector pump line is.we need these ptc heaters to slap onto the metal injector lines,to add heat where it counts. there is no way to splice a vegtherm into your injector feed lines.


1983 datsun 720, sd22 "GOIN'ON GREASE"
 
Location: orlando,fla | Registered: December 21, 2003Reply With QuoteReport This Post
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not putting them in the lines, just want to slap them on where all 4 injector feed lines run together, to heat the oil just before injection, to recover the heat the ip sucked out of the fuel.


1983 datsun 720, sd22 "GOIN'ON GREASE"
 
Location: orlando,fla | Registered: December 21, 2003Reply With QuoteReport This Post
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Has anyone tried cleaning the galvanizing off the injector lines and soldering water pipes to the outside of the injector lines for secondary heating just before injection?

It seems like if those lines got the hottest water, and there was some foam wrap around the outside of them, that it should transfer a fair amount of heat. Flow rates are VERY low in the injector lines - so it's got lots of time to cook. On the other hand, there probably isn't much turbulence inside the injector line, so transfer may not be so great.

Anyone know what kind of tubing they make the injector lines out of, or whether there is any heat treatment that might get screwed up by soldering to them?

Eric K
 
Location: Saginaw, MI, USA | Registered: January 30, 2002Reply With QuoteReport This Post
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We've used hoseclamps to attach Vegtherms on the injector hardlines on Mercedes - they fan out in this nice neat and flat pattern, so my thought was that I'd be adding some heat directly to the hardlines about 6" from the injectors. hasn't degraded the plating on the hardlines - looks like it's probably gold zinc plating.

Craig


www.PlantDrive.com

1972 Land Rover Defender/Series Hybrid, 300Tdi, Two-Tank PlantDrive system: HotFox, Vormax, Vegtherm Standard
Wife's car: 2001 VW Tdi New Beetle: PlantDrive TwoTank system: Donut tank for start-stop, VegMax, Vegtherm standard, 3-3-port valves, controller
 
Location: Berkeley, California, USA | Registered: March 04, 2002Reply With QuoteReport This Post



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Originally posted by Dieselrover:
We've used hoseclamps to attach Vegtherms on the injector hardlines on Mercedes - ....

Craig


Do you have a picture of this? Have you tested to show if it actually heats the oil. Seems there would be so little contact with the vegtherm unless you had one vegtherm on each injector line.


_________________________
If you believe you can't YOUR RIGHT;

But equally so.... if you believe you can, YOUR RIGHT as well.
 
Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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If you look at the pics you posted for me (thanks again) in response to Jimmy Joe's looping question, you'll see the Vegtherms mounted on the injector hardlines - and that's pretty much how they'd look with Vegtherms mounted directly on them with hose clamps - so the flat part of the Vegtherm is sitting right on the lines - should be enough to impart some heat to the lines, I think.

Craig


www.PlantDrive.com

1972 Land Rover Defender/Series Hybrid, 300Tdi, Two-Tank PlantDrive system: HotFox, Vormax, Vegtherm Standard
Wife's car: 2001 VW Tdi New Beetle: PlantDrive TwoTank system: Donut tank for start-stop, VegMax, Vegtherm standard, 3-3-port valves, controller
 
Location: Berkeley, California, USA | Registered: March 04, 2002Reply With QuoteReport This Post
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Originally posted by Dieselrover:
If you look at the pics you posted for me (thanks again) in response to Jimmy Joe's looping question, you'll see the Vegtherms mounted on the injector hardlines - and that's pretty much how they'd look with Vegtherms mounted directly on them with hose clamps - so the flat part of the Vegtherm is sitting right on the lines - should be enough to impart some heat to the lines, I think.

Craig

I asked this question once before but didn't see any reply to prove or disprove my hypothesis.

If the injector temperature is at or above the head temperature (which is above coolant temperature - the coolant cools the head and block) wouldn't the veg-oil in the injector, just prior to injection, heat to near the injector temperature (low flow rate, high residence time in injector)?
 
Location: Perth W.Australia | Registered: August 10, 2001Reply With QuoteReport This Post
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Originally posted by Tony from West Oz:
.....
If the injector temperature is at or above the head temperature ... wouldn't the veg-oil in the injector, just prior to injection, heat to near the injector temperature (low flow rate, high residence time in injector)?


Not knowing the science of all this yet but from what you are saying and from past reading I assume the metal line between IP and the actual injector stays full of oil till the injector opens on a DI engine. If I understand correctly then I would think yeah the oil in there is hotter than coolant temp and closer to IP/head temp. ifffffff..... it was insulated. Not sure how much that metal line as it is exposed engine compartment actually allows the oil to cool off while waiting for the injector to pop open. Granted that is only micro seconds though.


_________________________
If you believe you can't YOUR RIGHT;

But equally so.... if you believe you can, YOUR RIGHT as well.
 
Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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Originally posted by jeepin, moggin Jessup:
quote:
Originally posted by Tony from West Oz:
.....
If the injector temperature is at or above the head temperature ... wouldn't the veg-oil in the injector, just prior to injection, heat to near the injector temperature (low flow rate, high residence time in injector)?

Not knowing the science of all this yet but from what you are saying and from past reading I assume the metal line between IP and the actual injector stays full of oil till the injector opens on a DI engine. If I understand correctly then I would think yeah the oil in there is hotter than coolant temp and closer to IP/head temp. ifffffff..... it was insulated. Not sure how much that metal line as it is exposed engine compartment actually allows the oil to cool off while waiting for the injector to pop open. Granted that is only micro seconds though.

JMJ, the amount of fuel injected is significantly less than 1 ml at a time. This fuel is sitting in the injector, and I feel would be at around the same temperature as the injector itself, regardless of the temperature as it enters the injector.
if the engine is doing 3600rpm @100km/h and gets 10 km/l, then the engine is using 1 liter every 6 minutes, or (3600 * 6) revolutions. If it is a 4 stroke 4 cylinder engine, that means that on every revolution there are 2 injection points, so there are 2 * 3600 * 6 injections per litre
This calculates to 2.31 * 10-5 litres, or about 0.02 ml per injection.
Please check my maths, it is a long time since high school.
 
Location: Perth W.Australia | Registered: August 10, 2001Reply With QuoteReport This Post
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Originally posted by Tony from West Oz:
..
JMJ, the amount of fuel injected....

Thanks for the info Tony. I'll trust your mathBig Grin

While the amount of fuel and the heat inside the actual injector has some importance; the topic at hand (PTC heaters on the injector lines) I think is more about how much fuel/oil and how hot the fuel/oil is inside the metal tubes between the IP and the actual injector. I guess an importanf factor is also how fast does the fuel in those tubes flow. Answeres/guestimations to these questions may give us more info on if a PIC can make a significant change in temp of the vege while in these metal injector feed lines.


_________________________
If you believe you can't YOUR RIGHT;

But equally so.... if you believe you can, YOUR RIGHT as well.
 
Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post



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i would NOT solder anything to the injector feed lines, if you heat them up that much, you are sure to get some burnt bits of fuel inside them,which will go straight to the injector nozzle when you start up.if you have to do it, remove and drain them first, then run some good solvent through them before you hook them back up. i noticed, all theories and speculation aside, my truck will idle better with the injector lines heated up. true, they are hot,anyway, but adding heat makes mine idle better.


1983 datsun 720, sd22 "GOIN'ON GREASE"
 
Location: orlando,fla | Registered: December 21, 2003Reply With QuoteReport This Post
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its a pretty easy figure, to get flow rate, figure max speed roughly 60 mph, @30 mpg= 2gal per hour total,1/2gal per hour per line on a 4 cyl.


1983 datsun 720, sd22 "GOIN'ON GREASE"
 
Location: orlando,fla | Registered: December 21, 2003Reply With QuoteReport This Post
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