30k Fuel Fired Arctic Heater Installation

[74M35A2]

Hope this is in the right section, since it is pertaining to installation of a factory option:

Seeking opinions and the installation manual for converting an M925A2 from coolant heat to the 30k fuel fired arctic heater for the cab. I have seen these heaters installed under hood in the location of the heater core and blower. I have purchased a 30k fuel fired unit, and wondering if any modifications need to he made to the diverter box inside the cab when changing over to the fuel fired heater.

My concern here is that the air temp leaving the fuel fired heater could he much higher than the heater core air temp, so I am not sure if any changes have to be made such as the duct hosing or any felt/rubber seals within the diverter box?

Also accepting opinions of anybody that has the 30k fuel fired unit installed and working on their 939 series.

Thanks as always.

 

[rosco]

The fuel fired heater is part of an Arctic Winterization Kit. Pictured is the wrong truck, but the typical location for either a coolant heater, or the fuel fired heater. The air temperature will be higher, but within tolerance.

 

[gimpyrobb]

Bkubu had one at Aberdeen one year when it was cold and raining. It was really a life saver! Pretty sure they just take the place of the coolant heater, but make sure you don't use it as a defroster, they crack the windshields!

 

[cranetruck]

Bkubu had one at Aberdeen one year when it was cold and raining. It was really a life saver! Pretty sure they just take the place of the coolant heater, but make sure you don't use it as a defroster, they crack the windshields!

Yeah Gimp, that was in '08 and I believe the truck belonged to Chris (steelsoldiers) at the time.
Here he is, enjoying the heat:

 

[cranetruck]

The ducting must be replaced with SCAT, silicon rubber, the orange stuff.

 

[cranetruck]

Here are some images that may help, showing discharge air temps and the ducts. I used neoprene rubber ducts further away from the heater, since I found the orange slightly distracting when driving (yours will be hidden and no problem in that respect). Note the deflector in front of the defroster nozzle to prevent really hot air from cracking the windshield glass.


You can get the ducting from Aircraft Spruce.

 

[74M35A2]

Just what I was looking for. Thanks all.

 

[rosco]

The orange ducting is more desirable to work with. The early ducting that it replaced was a dark brown, like in my 211's, was fiberglas, which was very unpleasant, indeed. The heaters put out plenty of heat that is often best regulated by simply rolling down the window. The brass rod, fixed to the defroster duct, is a glove drier, and the black knob is a Tractor Protection Valve.

 

[74M35A2]

Exactly why I am doing the change over. 9F this morning here in MI, and. I want to be able to take my kids to school in it without them getting frostbite. Window down to control the temp would be a dream come true for me, thanks.

 

[tractors0130]

My heater melted the plastic covered cables under the dash; however it did feel nice and toasty.

 

[74M35A2]

Hey bud! Always good to hear from you (I bought my M925A2 from him last year, and put 5,000 miles on it so far in 1 approx. year). Please tell me more, such as how did that happen, what heater did you use, how well does it work, mounting tips (just reuse the heater core support plate?) and maybe an install pic under hood, such as how you routed the heater combustion exhaust. I think the 30k BTU fuel fired heater can switch from low to high, so 15k/30k BTU respectively? Did you change duct hoses? Did you have to pull the dash to change the defrost ones? Thanks a bunch.

I bought a 60K BTU unit, but that puts out so much heat I don't think I can control it, even with the windows down, so I will likely put that in the bed with the cargo cover, on detachable brackets.

 

[gimpyrobb]

Mount it in the bed and duct it in the rear soft top winder!

 

[74M35A2]

I actually was going to mount in atop of the passenger side tool box, and duct it into the right pane of the rear view window (hard top) by making a tin plate the same size as the window pane, kind of like how a window A/C unit mounts in a house. I still may just do this, and run it on low. It's an 8" duct. We'll see. It is so cold in this truck in MI right now, I have been on a fuel fired heater buying bonanza. Bought this 60k from a scholar, and also a 30k one from another fabulous gent. I don't want to be limited to just using this fun of a vehicle only part of the year. Thanks to all that are buzzing in here.

 

[tractors0130]

Hey bud! Always good to hear from you (I bought my M925A2 from him last year, and put 5,000 miles on it so far in 1 approx. year). Please tell me more, such as how did that happen, what heater did you use, how well does it work, mounting tips (just reuse the heater core support plate?) and maybe an install pic under hood, such as how you routed the heater combustion exhaust. I think the 30k BTU fuel fired heater can switch from low to high, so 15k/30k BTU respectively? Did you change duct hoses? Did you have to pull the dash to change the defrost ones? Thanks a bunch.

I bought a 60K BTU unit, but that puts out so much heat I don't think I can control it, even with the windows down, so I will likely put that in the bed with the cargo cover, on detachable brackets.

The M925A2 that I had with the 30K fuel fired heater came with it already mounted, somewhere I have some underhood shots of the mounting.
It had the Facet style cylindrical style fuel pump that fed it and it was tee'd off of the main fuel line near the tank with a quarter turn brass shut-off valve. The exhaust had a long flex tube that ran down just below the cab. That truck is now in California where they probably don't even need a heater. I'll post the pics, if I can find them.
Have you thought about mounting the heater under the passenger seat and moving your batteries outside?

 

[74M35A2]

No, but that is a fabulous idea. I'm getting ready to change over to group 31 batteries due to the age of my 6TL's, even though they are still cranking just fine. The engine fires quickly even when cold (with the factory shot of ether), so I may start with two 1150CCA batteries and see how she does while it is still winter. I can also put on one of the gear reduction starters my company makes, as they pull on average 50 amps less current during cranking. With only 2 group 31's under the bench, I may be able to move the coolant type heater to under the seat, and have it inhale and exhale cab air through the seat base front. Also may give a new meaning to heated seats.

 

[tractors0130]

FYI,
Here's a few pics of the arctic heater install in a M939 series truck. Also showing is the exhaust tube routing of the heater.

 

[74M35A2]

Thanks. Looks pretty straight forward. I hope you don't mind I used a pic in the want ads here to try and find the mounting brackets. Trying to find the cradle brackets for the heater is like hens teeth I would presume. Should be able to bend up something similar from strap iron, or fabricate two "shoes" for it to sit into, like the base of a 4" muffler clamp for example, if I need to.

 

[Baradium]

I had taken a bunch of pictures of the installation of the heater on a truck that was up at a local auction (not gov liq) last year. Truck must've been run at a mine and wasn't in very good shape, but it did have an original heater... so then the sd card on my phone died and I've lost those pictures as well as a number of other ones I wanted to save for reference.

 

[gimpyrobb]

Thanks. Looks pretty straight forward. I hope you don't mind I used a pic in the want ads here to try and find the mounting brackets. Trying to find the cradle brackets for the heater is like hens teeth I would presume. Should be able to bend up something similar from strap iron, or fabricate two "shoes" for it to sit into, like the base of a 4" muffler clamp for example, if I need to.

I might be able to help! I think I have some parts stashed here somewhere. Give me some time to locate.


(Its the least I could do, seeing as whats sitting on my porch today)

 

[74M35A2]

You don't owe me anything, you paid in advance. But I will buy the brackets from you if by chance you have them. No expectations.