Diesel heater vs. coolant heater

[cranetruck]

......... Secondly, and maybe it is just mine, but when I shut it off due to a 95 degree cab temp, and then try to start it while moving, it will not start. ........

Interesting....how many times has this been the case and at what speed? How is the exhaust pipe routed, is there enough "road draft" to effect the airflow?

During the start operation, the fan runs slower than normal, but there is still an air flow.
Which fuel pump are you using?

 

[atankersdad]

As slow as 5 mph, it will not start or restart. I have tried it countless times, and it has NEVER refired while moving. It fired right up after 3 tries yesterday, at 6 degress outside and the truck had just beem started. So it lights off easily. I am going to take a set of prints with me to work and get one of our instrument techs to find the weak link, or what is holding out the heater from starting. I will pm you on what I find.

EDIT: It is piped according to the PM with the exhaust in the left wheel well , closest to the firewall , about 14" above the ground. I suspect the air coming into the fan, is preventing it from lighting, or it is not detecting that it is lit.

 

[cranetruck]

Much appreciated.
I don't think it's a normal "behavior", may have something to do with the wiring....does the pilot light glow when you test it while driving?

Perhaps engine vibrations cause problems with possible bad connection(s)...

 

[Jones]

I had a fuel-fired heater in my M-37 and it wouldn't light while moving either. I always figured air moving past the exhaust tip was the problem so I'd just pull to the shoulder of the road and stop, light off the heater and take off again. A minor inconvienence for instant t-shirt weather.

With the US military starting to use them a few years back, the Swingfire units are showing up more and more (part of the "artic kit"). The burner assy. can either be slid into a water jacketed housing to heat engine coolant or into a heat exchanger unit for crew/troop compartment heat. Most are gasoline-fired from their own little fuel tank, but I've heard of diesel-fired versions (rarer and pricey).
Here's the manual, if you want to read up on the units.

 

[Camoclad]

my coolant heater works well even in sub zero. Just takes a while to warm up. I do however have my cab insulated with the gi od green sleeping mats on floor and back of cab tub. ( $6 from Colemans military surplus) I also have new window and door weatherstripping and use the grill cover. Just my 2 cents

 

[atankersdad]

This post got me curious. I went out and fired up my truck. The fuel heater started on the first try and had the cab hot in 5 minutes. Now it was warn today, 34 degrees. I went thru the wiring checking connections and wiggling wires and it did not cut out. I went down the road, shut the heater off and tried restarting it. No go. Once I stopped it fired right up on the first try. The moral of this story is that if I need heat, I must stop. If it gets too hot I open a window, or strip, maybe both.

 

[M543A2]

Gimpyrobb:
Hello! Here are some pics of the engine heater on my M543A2 wrecker. We put it on this truck because if we need a truck to go, this one running can do all we need to get others going.
The fuel pump is drawing from a tee I installed at the engine fuel filters where the in-tank pump sends fuel into the filter set, sending it through an in-line filter to the heater. The block drain behind the turbo is the water outlet from the block to the heater. You can see where the outlet goes into the top water manifold by gravity circulation. I ran the exhaust out behind the tire on the right side. The heater control is one of the typical on/off, hi/lo controls, placed in the cab.
If you have more questions, you can email me: massey478@yahoo,com
Regards Marti

 

[M543A2]

Doug:
Hello! I am near Sidney, IN. I fly from Warsaw to Rochester to catch the restaurants there often. Are you in Rochester or Akron? You mention both. Feel free to call if you need help. 260-839-5741

 

[cranetruck]

Excellent work M543A2, it shows that you have a good understanding for the workings of the system.

 

[beck]

Will the fuel heaters work with WMO

Will these heaters work on WMO? If not what % (if any) of WMO can they tolerate?

 

[cranetruck]

The heaters were improved in the 1950-60's to burn diesel, including DF2. I think the viscosity is a big factor and purity, since the fuel must be vaporized and also wicked (cotton/fiberglass wick) without contaminating the wick.
You decide.

 

[gimpyrobb]

Marti, thank you so much! That is exactly what I was looking for. Good point on the wrecker getting priority, I think mine will go in the 109 first and the wrecker will get the next one I find. This site and it's members rock.

 

[ccequipment]

Heres some pics of my unit and my truck I just finished, just a little eye candy. I also wanted to ask you guys, I have to hold the start switch for about 60-90 seconds on my Southwind before it fires, is this normal.

 

[cranetruck]

Gimpy, some things to consider....
Max fuel pressure for the control valve is 15 psi.
Place a petcock in coolant hose within easy reach, since it needs to be shut off when engine is running. I think Marti has one lower down on the block, hard to see.
The in-tank fuel pump will draw about as much current as the heater and original (Bendix) pump combined if you are concerned about battery drain.

 

[cranetruck]

Heres some pics of my unit and my truck I just finished, just a little eye candy. I also wanted to ask you guys, I have to hold the start switch for about 60-90 seconds on my Southwind before it fires, is this normal.

Yes, very normal. It takes about 20 seconds before the flame can be heard and then another 20 to 30 seconds before the flame detector reacts.

 

[ccequipment]

Thanks, I figured it was.

 

[elkhunter]

Does anyone know where I can get a switch for my diesel heater?

 

[gimpyrobb]

Sermis gets them from time to time. Try sending him a PM.

 

[elkhunter]

Who is sermis? Thanks!!

 

[M543A2]

We have used diesel and gasoline in the different kinds of Southwind heaters, but that is all. I do not think they would like any thicker oils in cold weather because they have some very small orifices for the high/low fuel selections in the fuel control modules. Thicker oils might not flow in the correct volume through them, but that is only an opinion from what I have seen when disassembling the valves to clean them.
The Benmar heaters I have that will replace the hot water heaters on my trucks have a different ignition system on them, as Bjorn has related, and possibly different control valves, but I have not gotten into them to be able to comment. Bjorn would possibly be able to relate more about this to us.
Regards Marti