diesel engine temps

[rj's barn]

What kind of engine temps should I see in a sub-compact diesel tractor?
There isnt a thermostat to regulate temperature but it still has a water pump to keep the water going. It is a 1.2 liter k4c mitsubishi industrial diesel. My after market temp gauge indicates a good constant 220 degrees when im brush hogging and working it. A digital temp gun indicates around the 205 to 210 mark at the upper water neck, 180's at the top of the radiator, and the 150's at the lower hose headed back into the engine. Does that sound about right?

 

[OhioTC18]

To me that sounds about right. A cooling system under pressure will boil at a higher temp than 212 degrees.
I would think 150 at the return would be a good thing.

 

[rj's barn]

temps

how far do you think 50/50 antifreeze to water modifies the boiling point? Should I run it leaner and sacrifice lubricity for cooling capability? Should I run "water wetter" in my coolant just to be on the safe side? I'd hate to run this thing on a 115 degree Oklahoma day and see temps of 230 or 240. What I really don't know is the shut off point of the engine. I saw 220 on my scale and almost panicked. The engine is an old cast iron block and head with a brass core and tank radiator so I know it's tough, but I don't know how tough. How hot do you think my upper water neck temp should be before I consider letting it run idle and cool off? Thanx!

 

[Brutus]

This applies to just about any liquid cooled engine: The hotter you can run'em without boiling it over, the better. Your engine components will be operating at maximum efficiency due to material expansion creating optimum tolerances.
One thing though, when you get ready to shut down after running at those temps, idle the engine for about five minutes to keep water circulating which will cool down the "hot spots" in the block to prevent warpage.

 

[haffasst]

rj, rule of thumb is every lb of pressure on the radiator will raise the boiling temp 3 degrees. If you have a 7 lb cap, the water in the radiator will not boil until 212+21 or 233 degrees. Mine runs pretty hot. I haven't put a guage on it yet,"it came with idiot lights" but it has never overheated.