MC9 block heater

[mike802]

My son was installing new fuel line on the bus and he plugged in the block heater for about an hour, he first cleaned up the prongs on the plug, but after about an hour the canister was still cold.  It looks like this heater heats the coolant, but not really sure. Should the canister that the plug comes out of warmed up some within an hour?

[luvrbus]

The factory block heater should come out lower right hand front corner of the block I don't know what you have there

good luck

[gumpy]

Sounds like you might have an aftermarket thermosiphon tank heater installed. Maybe you could post some photos. 

If that's what you have, then yes, the tank itself will heat up right away if it's working properly. They work basically by heating the coolant in the canister, which flows out the top, sucking in cool coolant at the bottom. These were typical as aftermarket installation on automobiles in the 70's and 80's. It's more common not to have the in-block element that goes into a freeze plug on automobiles, and that is what the typical Detroit block heater is like; a small element installed directly into the block, as Cliff indicated in his previous post.

[mike802]

I went out later this afternoon and helped with the fuel lines and got a closer look at it, it definitely is plumbed into the coolant lines, so it must be the aftermarket product, I will try and get some pictures tomorrow.  Is the aftermarket version better, or worse than the OEM version?  I am assuming that the aftermarket product will be more difficult to get parts for and repair, so if there is no real advantage to having it maybe I should just give Luke a call and instal an OEM unit.

[gumpy]

If it's what I am thinking of, it's probably not repairable.  All it consists of is an element inside the canister which heats the coolant, and the coolant then flows via thermo siphon.
There are no pumps in the units I'm familiar with.

The in-block heater would definitely be a better choice as it will heat the coolant directly inside the block, whereas this thing requires it to circulate in and out of the block
through the plumbing hoses in order to get the block heated. While that may work on a Chevy 350 engine, I have my doubts about it's efficiency on a 6v92 in very cold weather.

[Scott & Heather]

I could be wrong, but my heater appears to thread directly into my oil pan. Or am I confused?

[bevans6]

There are lots of different kinds of block heaters.  The two that seem to be most common as "factory" are the ones that screw into a pipe fitting on the right hand front face of the block under the head, or mount on the blanking plate on the right hand front side of the block under the exhaust manifold.  I have the former, and it works great.  Those two work by heating the water in the cooling system of the block.  You can also have an oil heater screwed into one of the ports on the oil pan - it won't warm the block but will obviously warm the oil.  I like warming the block because it slightly helps get the air temp up for easier combustion when cold, but the oil warming will help with spinning the engine over faster and less wear from really cold thick oil.

Brian

[buswarrior]

In a Freightliner I knew, with a Cummins ISM, there was a covered plug to which you attached an extension cord.

That plug separated behind the scenes into a line to an engine block heater, and a line to an engine oil pan heater.

Together, they didn't trip a 15 amp breaker.

Best of both worlds, warm block, and warm oil.

In the block is the way to go for an electric heater for a big engine.

Or, a coolant boiler of some sort, Webasto, Proheat or Espar.

happy coaching!
buswarrior