Adding 3 gauge sets

[California]

If you're researching to improve thermosiphon summer heat transfer and also guarantee freeze protection to 25 below all without seasonal replacement, I can see that is a worthwhile goal. Is the same coolant you used before still available, and does online research indicate there is material room for improvement?


Water pump / no thermostat on the YM240. I think these run cooler than is now considered optimal for a diesel. But the fuel economy is phenomenal as well as the longevity so they must have got something right.

 

[Smoody]

Ok I'm home in town and can't see my gear at the moment. But I thought on mine that drain device in the left picture was midway in a small hose between the block and the lower radiator tank. Maybe I'm imagining things. The copper washer under the plug might suggest an oil passage??? Is it in line with the oil pressure sensor?

No, that plug is directly inline with the lower radiator hose, if you look closely in the pic you can see the rad hose to the left...I plan to change the coolant ratio and change oil this wekeend, ill remove that plug and see what comes out, my thinking it will be coolant.

 

[rScotty]

If you're researching to improve thermosiphon summer heat transfer and also guarantee freeze protection to 25 below all without seasonal replacement, I can see that is a worthwhile goal. Is the same coolant you used before still available, and does online research indicate there is material room for improvement?
Water pump / no thermostat on the YM240. I think these run cooler than is now considered optimal for a diesel. But the fuel economy is phenomenal as well as the longevity so they must have got something right.

Right you are! I was making an assumption and Yanmar sure fooled me. I apologize and hope it doesn't go any farther. From a closer look at the parts books I don't see any thermostat on the YM195, YM240, or the M330.....They have a water pump but no thermostat!! Wonder why? Who would'a thunk?

A closer look shows other weirdness in Yanmar's early water pump cooling systems from the early era.
The first ones in the US: 135/155/195/140/330. Not just that doomed dark ages thermosiphon system in the little ones, but the water pumpers have three ports on the pump and no variable flow control (from a thermostat). It's indeterminate just how much of what goes where. All in all a very "iffy" way to design something, though.

It's a strange system. Not at all like other elements of the Yanmar which show so much engineering brilliance - the early cooling systems show what I'd call engineering arrogance....possibly coupled with ignorance. Even the drains are strange. I have some perspective on this; just spent a decade designing flow control stuff for industry.

That YM186 is much nicer. I think of the the YM186 was the first of Yanmar's new US designs. The book shows it with a proper pump coupled with a thermostat.

Looking at exploded diagrams, that upper hose on the 240 provides a place just made to fit a thermostat. Has anyone done that? Come to think of it, has anyone done anything custom to improve any of the early Yanmar cooling systems?
rScotty

 

[California]

Ok, I recognize now I'm speculating about stuff where I know less than the two guys who clearly are better informed. If I had good sense I would sit back and just watch this thread evolve. Sorry guys.

But lacking that patience - - I'll still offer comments. Based on no evidence at all, I wonder if these 'dark ages' cooling systems were designed by engineers who started with Yanmar in the era of open-jacket cooling systems - where they just poured a bucket of ditch water into the open top of the enclosure before starting work each day, and drained the water on the ground at the first hint of frost. Did those systems have any radiator at all?

Scotty its interesting to hear your professional engineer's perspective on this. I didn't imagine Yanmar's early systems were so far from 'good practice' or at least conventional design. When did other applications abandon thermosiphon cooling? Was Ford's model T the last example of widespread use?

 

[284 International]

Scotty its interesting to hear your professional engineer's perspective on this. I didn't imagine Yanmar's early systems were so far from 'good practice' or at least conventional design. When did other applications abandon thermosiphon cooling? Was Ford's model T the last example of widespread use?

I'm continuing to read this thread with interest, and am eager to learn something, too.

I have wondered about a product like the Evan's waterless coolant Home » Engine Cooling Systems or some similar product, especially in the thermosiphon systems. I've heard second or third hand, anecdotally, the breadth of opinion from "This stuff saved my engine and is the best ever" to "I used this and my engine was destroyed."

My ignorance about this subject is near-complete, but I would imagine the cooling efficacy might be improved if the coolant could operate at a higher temperature gradient. Combined with a synthetic oil, might this be a reasonable way to make the thermosiphon systems have year-round functionality in cold climates and hot alike, without a need to change or adjust coolant ratios?

 

[rScotty]

Ok,
Scotty its interesting to hear your professional engineer's perspective on this. I didn't imagine Yanmar's early systems were so far from 'good practice' or at least conventional design. When did other applications abandon thermosiphon cooling? Was Ford's model T the last example of widespread use?

The most well known is the venerable John Deere 2 cylinder tractors. They built a lot of them, and they cooled OK. But those were big enough to take advantage of having the engine lower than the radiator. That helps a lot. Also, Yanmar was known for ship engines (still is) and that's an application at constant speed and load, on the level, and so it just possibly works well there too. But those are both by-gone days, and even if possible are far from optimal...
rScotty

 

[rScotty]

I'm continuing to read this thread with interest, and am eager to learn something, too.

I have wondered about a product like the Evan's waterless coolant Home » Engine Cooling Systems or some similar product, especially in the thermosiphon systems. I've heard second or third hand, anecdotally, the breadth of opinion from "This stuff saved my engine and is the best ever" to "I used this and my engine was destroyed."

My ignorance about this subject is near-complete, but I would imagine the cooling efficacy might be improved if the coolant could operate at a higher temperature gradient. Combined with a synthetic oil, might this be a reasonable way to make the thermosiphon systems have year-round functionality in cold climates and hot alike, without a need to change or adjust coolant ratios?

Well, an antifreeze that would conduct more heat rather than less would sure help. Good idea. I'll look around and see what's out there. But a water pump isn't the most complex thing to design either.
rScotty

 

[winston1]

The little farmall cubs also had the thermosiphon system. Worked great.

 

[284 International]

But a water pump isn't the most complex thing to design either.

When I was young, I "helped" my grandfather rebuild the water pump in his old Model A Ford. I recall having to re-wrap a piece of greased yarn several different times so it was properly aligned (I'm still not entirely clear what he was looking for, maybe it was just to keep me out of his way?) and then watching while things were tightened just so; the pump was supposed to leak a tiny bit but not too much, apparently. That has permanently colored my perceptions of how leaky things can be and still be acceptable!

For a company that advises cleaning fuel injectors with a wooden dowel and mutton tallow, I'm surprised they weren't able to fit even a rudimentary, packed-seal water pump onto those tractors. As you said, compared to the remainder of the precision put into the tractors, it isn't THAT complex.