M not cooling

[tmloos]

Hi,
I started a rebuilt engine on my MC for the first time today. After about 3-5 minutes of running, I noticed that the upper hose was hot and the lower hose was cold. There is no pump or thermostat on these so I am scratching my head! My first thought is that there is a plug somewhere but I wanted to ask the community what you all think. The radiator looks like it is newly re-cored, but it could be plugged who knows. Does anyone have any experience with this? And I thought the thermosiphon was a simple concept...

 

[James Williams]

How hot is hot,It sounds like its working OK to me

jimmy

 

[rick deere]

normal

 

[BushogPapa]

That's the way it works--Heat Rises...

Still, without a Shutter in front of the radiator, it likely will never get up to 160* even if you work it hard...

Ron..

 

[M-MAN]

That isn't enough time to even start getting warmed up. You didn't ask but - ALWAYS premix the antifreeze on a thermosiphon system. Leave a few inches of airspace in the top of the radiator. Down south expect running temps of 200 to 225. This is normal for an M & won't hurt a thing.

 

[buickanddeere]

If coolant isn't boiling out the rad cap, she's fine.

 

[Hotflashjr]

The thermosyphon system works where the hot coolant moves through the top hose, down through the rad and the cool back into the engine through the bottom hose. Any chance you used two wire hose clamps? These stupid things are giving me a fit on my MT. They just won't stop weeping. I like the look but I think I am going to modern band style clamps.