1941 Dodge- Engine Heater?

mitch504 · Dec 12, 2019

I have a good customer who is a multi-millionaire lawyer who owns a big deer farm. One of his favorite toys is a 1941 Dodge military truck (the first thing to carry the name jeep). It has the original flathead 6 with a single barrel carb. He wants this thing to start and run like it is warm even at 25f. There is not much market for engine heaters here, do any of you Yankees think a heater in the lower radiator hose would work? I was looking at the circulating ones, but this thing has no heater hose to route it back into.

Delmer · Dec 12, 2019

Yes, it will work fine. A block heater (core plug) is the standard, and that's what I'd try first. I'm sure the engine has a core plug, you just might have to have the engine down for a week waiting on the right heater, or a replacement core plug if there's no room for a heating element in the first one you pick.

Bumpsteer · Dec 12, 2019

For as long as that basic truck was in production, throughout the war and up to about 1970. I would think a block heater would be available.

Ed

DIYDAVE · Dec 12, 2019

Go to Kat's web site, and start lookin. They can pretty much fit anything. A coupla notes, LR hose heater needs to be connected in a length of hose, with at least a 15º up tilt toward the motor. You may find that another type of heater may work better. The external tank heaters, that plug into the block drain and the thermostat bypass hose, are the best, in my experience...

http://www.fivestarmanufacturing.com/guides

Truck Shop · Dec 12, 2019

All that was available for those and or any flat head was a head bolt heater years ago. The main thing with the soft plug heater is the thickness of the block and that there is no cylinder in the way in
the water jacket. Those had small diameter soft plugs so that will be the biggest problem plus the the soft plus were the dish style not the cup style found today. So the sealing surface on the inside
may be rough. Lower hose heater truly would work the best if it will fit correctly. IMO. I'm guessing it's a Chrysler 241.

Truck Shop · Dec 13, 2019

http://www.fivestarmanufacturing.com/pdf/kats-catalog-complete-2019_outlined_fonts.pdf

GregsHD · Dec 13, 2019

I've got a lower rad hose heater on one of my tractors, it works ok at best, the unit gets pretty damn hot and I don't quite trust it. Is there much flat surface on the oil pan? If so, get a glue on oil pan heater pad. far superior to the rad hose heater and a cleaner install.

My question is, If he's that loaded, why not just build a heated garage!?!?!

kshansen · Dec 13, 2019

GregsHD said:
Is there much flat surface on the oil pan? If so, get a glue on oil pan heater pad. far superior to the rad hose heater and a cleaner install.

My question is, If he's that loaded, why not just build a heated garage!?!?!

Yes on the oil pan heater!

Go to Truck Shop's link:
http://www.fivestarmanufacturing.com/pdf/kats-catalog-complete-2019_outlined_fonts.pdf

And scroll down to near the end around page 83 or 85 and see this:

I figure if this thing does not have a heater the important thing is to get the oil warm so it cranks over good and easy. Have you looked into converting it to 12 volts, assume it was/is originally a 6 volt system. A 6 volt starter will work good on 12 volts so main thing would be converting lights and charging system. Check out some old farm tractor forums and I bet someone there can tell you how to modify the generator to do 12 volts!

Truck Shop · Dec 13, 2019

Kind of puzzled why most you don't like lower hose heaters-same basic wattage as a frost plug heater. The benefit of a lower hose heater is that it will keep the radiator warm also.
I had run them for years in my older rigs and never a problem-you just need to check the connection at the heater now and then to make sure there is no corrosion. I had the same
lower hose heater in my 84 Dodge for the entire time I owned it {23 years} and used it every winter.

kshansen · Dec 13, 2019

Truck Shop said:
Kind of puzzled why most you don't like lower hose heaters-same basic wattage as a frost plug heater. The benefit of a lower hose heater is that it will keep the radiator warm also.
I had run them for years in my older rigs and never a problem-you just need to check the connection at the heater now and then to make sure there is no corrosion. I had the same
lower hose heater in my 84 Dodge for the entire time I owned it {23 years} and used it every winter.

It's not that I don't like them but was just thinking that heating the oil might be a good option. As this truck does not have a cab or heater heating the coolant might not be as important as having warm oil flowing to the bearings on start up.

If there is room to fit a lower hose heater in that should do fine and look nice.

Besides to me if the coldest temps it is going to see is 25ºF I would not even call that cold!

DIYDAVE · Dec 13, 2019

Problem I've had with the pad or magnet type heaters is that they don't seem to heat it up much. On my lil kuboters, I use one of these, just slide it under the motor, and in 1/2 hr or so, the engine is warm to the touch, no electricity needed. Don't use these on leaky motors.

crane operator · Dec 13, 2019

Does it have a manual choke on the single barrel carb? I wouldn't think that it would be a very hard starting engine at 25 deg.

I drove a '67 chevy pickup with a inline 6 for years in below zero winter temps, with no block heater where I grew up in central iowa. It was manual choke and that has it all over a "automatic" choke, especially one that isn't working quite right.

We didn't plug in anything in Iowa that wasn't a diesel. And it wasn't unusual to have a week or two in january or feb, where it wouldn't reach 0. 25 degrees is a pretty nice day up minnesota direction. Where I live now we don't see those colder temps.

I kind of like khansens suggestion for going 12volt, that would make a big difference on cranking fast/ battery strength in the cold. It shouldn't have enough compression to turn over hard.

I think a lower radiator hose heater would be the cheapest and easiest. I didn't know about the different frost plugs that truckshop pointed out, but that would make real issues sealing up.

GregsHD · Dec 14, 2019

Yeah 25f isn't cold! I'm sure it'll fire up fine.

The higher wattage oil pan pads work well, the magnetic ones aren't of much use.

I'll say the rad hose heaters are definitely the cheapest and easiest, not sure the wattage of mine, it takes a while when -20f or below (I'm used to min 1000w block heaters). Unit does get sizzling hot though, seems a bit hard on the hose.

Truck Shop · Dec 14, 2019

I used a timer with the lower hose heater and set it for two hours before I would leave in the morning to cut down on electrical cost, I think the ones I used were around 6 to 700 watt.
The problem with the old engines that used expansion plugs in stead of the cup type soft plus of later years is the block only has a small shallow counter bore for the expansion plug
and the rest of the opening is rough cast in most cases unlike the machined surface that a cup type has.
The other problem I can see with a six volt system is the ignition, more than likely the wiring is old and
has resistance. Those old flat heads would start cold but the ignition system needed to be in top form
for a good blue spark.

92U 3406 · Dec 14, 2019

kshansen said:
It's not that I don't like them but was just thinking that heating the oil might be a good option. As this truck does not have a cab or heater heating the coolant might not be as important as having warm oil flowing to the bearings on start up.

If there is room to fit a lower hose heater in that should do fine and look nice.

Besides to me if the coldest temps it is going to see is 25ºF I would not even call that cold!

I don't even plug in anything until it hits about 10F.

Delmer · Dec 14, 2019

another option is the silicone pad heaters that you glue to the oil pan, except glue it to the side of the water jacket part of the block.

RZucker · Dec 14, 2019

Delmer said:
another option is the silicone pad heaters that you glue to the oil pan, except glue it to the side of the water jacket part of the block.

Had a forklift with a 3 cylinder Duetz air cooled. the pan heater was a big help in the cold.

Truck Shop · Dec 14, 2019

92U 3406 said:
I don't even plug in anything until it hits about 10F.

When you get old and wrinkly and arthritis starts setting up house keeping in your bones, you will want a warm car interior-pronto pup.

kshansen · Dec 14, 2019

Truck Shop said:
When you get old and wrinkly and arthritis starts setting up house keeping in your bones, you will want a warm car interior-pronto pup.

Well then I don't think many of us here would want to take a ride in that 1941 Dodge at least not till next May at the soonest!

mowingman · Dec 14, 2019

Bumpsteer said:
For as long as that basic truck was in production, throughout the war and up to about 1970. I would think a block heater would be available.

Ed

That truck was not available after the war. You are thinking of the WM300-type trucks, (Power Wagon), that were built after the war. This truck does not have the same engine, although they did use a flathead 6 cylinder in the WM300 Power Wagons. I believe a few of the last WM300's, that were built only for export, may have had a slant 6 in them.
You might want to ask this question over on the Dodge Power Wagon forum. There is a ton of info available from the guys over there. www.dodgepowerwagon.com

1941 Dodge- Engine Heater?

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