Injector temperature

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Injector temperature

Postby othello » Fri Mar 30, 2012 5:34 pm

My WVO is not getting hot enough.
So I checked various points on the fuel lines with a thermistor temp gauge which is very responsive due to the low thermal mass.

And I have two questions.

Should the loop heating the veggie filter (and the veggie tank) not be in line with the cars cooling system, as opposed to in parallel??
I think I may have low flow thru the veggie filter, which may contribute to my low temp problem.

The other question I have is where to measure the temperature of the hot WVO.
I have inserted a sensor before my fuel line enters the injection pump, but should one not measure the temperature on the metal line right before the injectors themselves, because this is where the temperature counts.
And on my Mercedes 300 TD the temperature is definitely different at the two spots.
othello
 
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Re: Injector temperature

Postby John Galt » Fri Mar 30, 2012 10:29 pm

This discussion will help sort that out:
http://www.frybrid.com/forum/showthread.php?t=19363

The terms 'series' and 'parallel' are often misunderstood. The most reliable systems have the engine coolant circuit connected like this:

╔=coolant pump====╗
╠=cab heater======╣
╠=FPHE ==========╣
╚=HOH+filter+etc===╝

should one ... measure the temperature on the metal line right before the injectors
That's where I take the temperature on my system. The probe is tight to the fuel line and covered with insulation so it accurately measures the line temperature.
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Re: Injector temperature

Postby othello » Sat Mar 31, 2012 10:05 pm

Thank you John, I moved the sensor to the injector line, but the temperature there is even more disappointing, 80 F.

Its about 120F at the veggie filter heater. Apparently it drops on it's way to the injector.
I have a 85 MB300 turbo diesel and the line to the injector is quite exposed.

So at this point it seems quite useless to concentrate on improving the temperature at the filter unless I can reduce the temperature drop on the way to the injectors, where it counts.

Following the thread you send me I am wondering about the plumbing for the filter heater.
Is the hottest point in the cooling circuit in my car by the firewall, driver side, or is it at the bottom of the radiator by the water pump down on the passenger side. My filter heater may be hooked up to the wrong side.
othello
 
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Re: Injector temperature

Postby svo100 » Sun Apr 01, 2012 10:56 am

othello wrote:Is the hottest point in the cooling circuit in my car by the firewall, driver side, or is it at the bottom of the radiator by the water pump down on the passenger side. My filter heater may be hooked up to the wrong side.



Ususally the hottest point is where the coolant leaves from the head to the cabin heater.
Hope this is what ya was looking for.
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Re: Injector temperature

Postby othello » Sun Apr 01, 2012 8:41 pm

Yes, this is what I needed to have confirmed.
Given how cold my oil is I need to methodically go thru my entire system to find the flaws.
I am working on a car with the greasecar system and what surprises me is that apparently no consideration is given to the temperature drop from the system components to the temperature past the IP to just in front of the injectors.
In my case at least coolant temperature bears no relation to the temperature in front of the injectors, which is way lower.
othello
 
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Re: Injector temperature

Postby othello » Mon Apr 02, 2012 6:17 pm

I checked on the thermostat today. My parts dealer says there is only one available and it is a 172 F MB thermostat.

That could of course partially explain the low temperatures.

Can I, should I install a hotter thermostat? And where would I find that since Mercedes seems to offer only this type.
othello
 
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Re: Injector temperature

Postby svo100 » Tue Apr 03, 2012 1:00 pm

I wanna try to help you out.. What yr is your MB ?

I would not use those thermo sensors you are using, i dont think they are trusty if its what i think your using, a metal senson tied down to your coolant/fuel line. Try to get a good laser-thermo. with that you can get wild and check how hot your injection pump, engine , coolant lines.. , example, a Bosch roatry pump gets up to 65-70c , the head is 82c or so..

Does your radiator get hot / warm ? how about the hose that goes from the waterpump/thermostat to the radiator, is it hard ( pressure ) It should be warm and hard when operating temp.

Does the engine warm up "normally" ? Mercedes 603 etc engines warm up so fast, its almost unbelievable.
IF your engine heats up, but your systems wont heat up properly, maybe install a 12 coolant pump. I have one behind a switch and there is a huge diffrence when using it or not.

Here in winter we cover the radiator completly, have engine pre-heaters.. it gets COLD .

Hope this helps
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Re: Injector temperature

Postby othello » Tue Apr 03, 2012 4:02 pm

Well thank you for your help, I think your thoughts are going in the right direction.
My Mercedes is a 300 turbo diesel, 1985.

The laser thermos just have the problem that you do have to get the emission of the item you want to measure just right, I have one and had varying success with it.


I think my coolant flow might be lacking. The hose is not as hard as I thought it might have to be, but there is coolant flowing, I checked that and the hose gets hot.

This Mercedes does not get hot as fast as another I drive, so there has always been a bit of a suspicion here.

But what about that thermostat, if there is no hotter thermostat available than the stock 176 F I am limited right there??

What coolant pump are you using?
othello
 
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Re: Injector temperature

Postby svo100 » Wed Apr 04, 2012 12:24 am

So this is a 123 ? cause its changes into a 124 right about 1985.

We have 2 diffrent therms. available, 80c( 176F) and 87c (188f) , summer / winter .
I use a bosch pump, but there are several out there.
If on a budget , go to a salvage yard and look for Mercedes,BMW, AUDI 1986--> usually has a bosch coolant pump . a new Bosch is $100 i think.. make sure flow direction is right when ya hook it up
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Re: Injector temperature

Postby othello » Wed Apr 04, 2012 3:36 pm

[quote="svo100"]So this is a 123 ? cause its changes into a 124 right about 1985.

We have 2 diffrent therms. available, 80c( 176F) and 87c (188f) , summer / winter .
[/quote]

It is a 123.

Who is "we", are you a business??
And where are these hotter thermostats available, I couldn't locate one. Are the thermostats special to Mercedes or do other brands fit?
Also do you have a type or a specification on that auxiliary water pump you mention??
othello
 
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Re: Injector temperature

Postby svo100 » Wed Apr 04, 2012 4:41 pm

I´m in Finland, your in the states, right ? By "we" , i meant like "up here"..
Over here they offer two type, Summer / Winter thermostat.

heres the pump

https://www.greaseworks.com/store/produ ... 2q5cdjpnc7
svo100
 
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Re: Injector temperature

Postby othello » Thu Apr 05, 2012 5:15 pm

I wish we had such thermostats over here.
My dealer says he could never locate anything but the 176F kind of thermostat.

Before I get myself an auxiliary coolant pump I would like to find out why the stock set up in my Mercedes apparently does not provide good coolant flow.
Maybe others here have experience with that topic.
othello
 
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Re: Injector temperature and more

Postby othello » Mon Apr 09, 2012 9:49 am

My outside temperature is a bit above freezing.
The hot point of my coolant loop shows 71 C.
After a couple of feet of rubber hose I measure 60+ at the filter heater ( I have a greasecar filter heater)
At the filter though I measure 30+C and the temperature decreases from there resulting in my initial complaint that at the injectors I have lukewarm oil.
I can drive as long as I want and this situation does not improve significantly.

I think this filter heat exchanger is not a good design. There is only spotty contact between the coil and the filter and obviously heat is not transferred as it should.
So before I do anything else I should get a proper filter heat exchanger which would elevate the coolant temperature more than this design.

What good designs are out there??
othello
 
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Re: Injector temperature

Postby SunWizard » Mon Apr 09, 2012 10:07 am

There are no heated filters that provide much heat, unless they have a FPHE built in. Keep the filter and add a FPHE to add a large heat exchange area.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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Re: Injector temperature

Postby othello » Mon Apr 09, 2012 12:59 pm

SunWizard wrote:There are no heated filters that provide much heat, unless they have a FPHE built in. Keep the filter and add a FPHE to add a large heat exchange area.

And I assume you would add the FPHE before the filter to give the filter the maximum benefit of already hotter oil?

And do you then top this off with eletcric line heaters for the steel lines leading to the injectors? In my Mercedes the steel lines are apt to loose a lot of heat from the IP to the injector.
othello
 
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