YM 155D Snow thrower??

[clemsonfor]

I thought that the ratio for thermosiphon systems for maximum flow was 30% coolant and 70% water.

I think that's summer. Won't you freeze up in the cold climates with 30% antifreeze? When it's 15f outside your not going t overheat unless you have a different problem so I don't think the ratio is as big a concern in winter. Other than for freeze protection.

 

[rScotty]

I thought that the ratio for thermosiphon systems for maximum flow was 30% coolant and 70% water.

Well, that will work of course....and not a bad bet if you live in the deep South. It all depends on the climate where the tractor lives. The ratio is a a balancing act depending on climate. Originally in their Service Information Bulletins circa about 1980, Yanmar gave the customer a graph and a series of numbers and and advised owners to mix for protection at the "lowest temperature anticipated".

The percentage you end up with is a sliding scale. It depends on where you live. The higher the percentage of ethylene glycol then the better the freeze protection at low temperature (up to a point)....BUT....the ethylene glycol doesn't transfer heat as well as water does, so a higher percentage of ethylene glycol means the cooling system isn't as efficient and doesn't cool as well..

BTW, there are different "coolants" today, but back when the Yanmar therosiphon system was designed the whole world used a mix of ethylene glycol and water. That was a cooling mixture that gained favor back in the 1940s and was used everywhere up until the 1990s or so. The Yanmar system is based on the assumption that the coolant you are using is pure ethylene glycol mixed with pure water. Other glycols are different.

And ethylene glycol is a weird substance itself. In pure form it freezes at a fairly high temperature....About 8 F. It is only when ethylene glycol is mixed with water that the freezing point goes way down and it becomes "antifreeze".

You can look up information on heat transfer rates of different mix percentages of water and ethylene glycol on line if curious.
Here ae SOME SPECS direct from Yanmar with my comments:

Pure water freezes (and could split the block) at 32 F. But it cools well in hot weather because it transfers heat from the engine to the radiator fins quite well.

If you replace 30% of the water with pure ethylene glycol so that you have a 30%/70% mix, that mixture won't freeze until the temperature drops below zero degress farenheit. = 0 F. Mixed like that, you've gained about 30 degrees of freeze protection and still got a mixture good for cooling during hard work in the summertime.
So if that is the climate where you live it will work for you in the winter and cool better in the summer.

40% ethylene glycol and 60% water freezes at -13 degrees F.

The MAXIMUM ethylene glycol that Yanmar recommends is 50%. A 50/50 mix of ethylene glycol and water is pretty good antifreeze. It won't freeze until the temperature gets below -36 degrees F. Since the OP lives in Nebraska, he would probably want to go with the 50/50 mix.

For Alaska or the far north, where temps are even lower those guys are going to have to run a 60/40 mixture which lowers the freezing point to -50F. But they are going to have to change it out or dilute back to a something under a 50/50 mix for the summer.

Paying attention to the ethylene glycol/water ratio is the maintenance price us old Yanmar guys pay for the simplicity of a thermosiphon system. Like a lot of the older Yanmar philosophy, it puts the work onto the owner instead of adding the complication and expense of adding another part to the tractor - in this case that would be a waterpump and thermostat.

Enjoy! rScotty - an old time Yanmar guy.

 

[Jtullis13]

Thanks for all that great information rScotty. I guess I did not specify very well in my post. I do not plan on putting in an extra thermostat, I plan on using a temperature probe in the upper radiator hose as I did on my 2210d. See the pictures I have attached. The probe shouldn't restrict much flow if any at all, this way I have an actual gauge and keep the dummy light in place too. rScotty do you have printed information on the coolant mixture that I could refer to? I live in Nebraska and it gets hotter than **** here in the summer and colder that a witches tit in the winter so I will have to keep an eye on my ratio for sure since this is a therosiphon system. As for the block heater, I have not been able to find an actual Yanmar one, however chevy791979 did provide the JD part number for their tractors which also have the same Yanmar engine as mine would, well maybe not the exact one, but a Yanmar engine for sure. Also I did notice that Hoye also sells a block heater and I would like to think that he would have the correct threads for it, but I could be wrong. Let me know your thoughts on this. Also I am digging up information on the appropriate size 3PH snowblower for this thing. I am thinking a 50" is the biggest I would be able to go, only because that is the only size I can find around here.

 

[chevy791979]

The JD part I gave you is the exact one you'll get from hoye. I got it because I work at Deere construction dealer and had it the next morning without paying shipping.

 

[Jtullis13]

Good to hear. I actually ordered that one from Hoye today because it was the cheapest I could find that was made for that engine.

 

[rScotty]

Thanks for all that great information rScotty. I guess I did not specify very well in my post. I do not plan on putting in an extra thermostat, I plan on using a temperature probe in the upper radiator hose as I did on my 2210d. See the pictures I have attached. The probe shouldn't restrict much flow if any at all, this way I have an actual gauge and keep the dummy light in place too. rScotty do you have printed information on the coolant mixture that I could refer to? I live in Nebraska and it gets hotter than **** here in the summer and colder that a witches tit in the winter so I will have to keep an eye on my ratio for sure since this is a therosiphon system. As for the block heater, I have not been able to find an actual Yanmar one, however chevy791979 did provide the JD part number for their tractors which also have the same Yanmar engine as mine would, well maybe not the exact one, but a Yanmar engine for sure. Also I did notice that Hoye also sells a block heater and I would like to think that he would have the correct threads for it, but I could be wrong. Let me know your thoughts on this. Also I am digging up information on the appropriate size 3PH snowblower for this thing. I am thinking a 50" is the biggest I would be able to go, only because that is the only size I can find around here.View attachment 577026

Yanmar printed a number of technical bulletins about ethylene glycol mixtures for their thermosiphon systems. They all say about the same thing, but as time went on they tried to make their mixture recommendations more "user friendly" and less technical. I've attached here a printed copy that has what I consider to be the best info.

I don't know what to expect from your radiator hose temperature probe in a thermosiphon system. Let us know how it works.
My guess - and it is just a guess - is that it would read a couple of degrees higher than a measurement made at the location of the block sensor that Yanmar used for their idiot light. Water pump systems circulate the water a lot faster than the thermosiphon so you can expect your temperature probe to show a bit differently on the YM155 from the 2210d. At least I'm assuming that the 2210d has a water pump .... I don't know the gray market Yanmars as well as I know the US models.

Thermosiphon cooling systems were originally developed for stationary engines back in an era when regulating operating temperature was something that people paid more attention to than they do today with modern pumped coolant circulation. Basically, water pumps became more popular as the hot water pump seal technology became better. Water pumps themselves used to be a high maintenance item, but no more. Thermosiphon circulation is driven by gravity instead of a pump, and never was very efficient. You'll probably even notice a difference in operating temperature between steep downhill and uphill operation. It's adequate if watched.

On my YM165 (same engine as the YM155) I replaced the on/off idiot light sensor in the block with a regular analogue temperature sender and gauge.

Here is also a photo of the analogue sensor. The sensor required an thread adapter to go from the
BTP tapered pipe threads in the Yanmar block to our NPT thread.

On the block heater, I'm sure that Hoye knows all this and will send the right block heater. Clean the threads well. Here is a picture of my block heater installation too.
Luck, rScotty

 

[Jtullis13]

The 2210d does have a water pump and I would agree with you on the fact that the temp probe for my 155d would read higher if I would install it as described. I could just remove the dummy light sensor and put probe in like you did your YM165. Do you happen to have the thread adapter size that you used for your temp sensor?

The block heater you have installed looks exactly like the one Hoye sells and just like the one chevy791979 posted, so I assume the one I will be getting should work just fine.

I appreciate the info on the antifreeze mixture and all the info you have provided me on the Thermosiphon cooling system, that has been very helpful. :thumbsup:

 

[Jtullis13]

Well I was able to change the front axle oil and engine oil. Installed the oil pressure gauge just like on my 2210d. Also installed that Header Tank which replaces the old Thermostart tank. I will say that I had a **** of a time removing that plug for the block heater!!! That thing was in there and had a ton of sealant on it. I had to use my torch to heat it up 6 times to get it to come out. Its in such a small area and didn't have a lot of room to move my wrench back and forth before it cooled down and wouldn't move again. Many minutes later I was able to get it out and install the block heater, which works like a champ, tried it out this morning.

 

[chevy791979]

Good to here. How'd it start this am?

 

[Jtullis13]

It started like a champ this morning. It was 32 degrees here and it was easy starting. :thumbsup: