Yong Heng, Radiator vs Ice, my results so far (Video added)

A higher volume water pump can not help cooling in a closed loop because each molecule of water spends the same amount of time being heated and cooled no matter how fast it makes laps through the loop. The only time it could help is if the water were reaching it's heat carrying limit which is close to boiling point and will not happen in these compressors.
The greatest limit to water cooling a yong heng is the lack of a cooling jacket on the cylinder. The water passes through a single straight skinny bore between the inlet and outlet so there is not enough contact surface to exchange the heat. Adding the tinniest drop of dish detergent to your water will break the surface tension of the water and allow it to contact slightly more surface area inside the tiny water passage in the compressor head but this won't be much.
Agreed 100%
 
I use a bigger pump in mine but my justification for that is my YH is at counter height and my water bucket is on the floor a couple of feet below it. I use a fairly large computer radiator with two fans on it. I also have a 8 inch fan blowing air across the YH motor and first stage fins. In the winter and portions of the spring and fall I do not use ice. My temperature stays at 60 degrees C or below. In the summer I add ice in the form of frozen soda bottles. I run the YH for around 20 minutes to refill my 45 minute SCBA tank. I also find that brake line has significantly less tendency to kink than vinyl hose and I think "water wetter" sold for cooling systems of cars is worthwhile.
Once the water reaches maximum pumping height and falls back down the siphon effect cancels out the head pressure so a larger pump isn't necessary.
Even though the oem pump can't lift water more than a few feet, if you lift the bucket to let it get through the compressor head just once it will be plenty of water flow even if the bucket were 20 feet below the compressor.

A tiny drop of dish soap will make you happier than water wetter because the latter is expensive and really smells bad.

If you run clear tubing on a closed loops system, add a few drops of copper sulfate solution to prevent algae growth.

Edit: I just wanted to add that I'm only sharing knowledge and experience. I don't mean to offend in any way.
 
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The suggestion that moving the water faster does not improve heat transfer from the YH is untrue. The rate of heat transfer is a function of the temperature difference between the higher temperature source and the lower temperature destination for the thermal energy. If you slow down the water flow, it spends more time close to the source of the thermal energy so it gets hotter reducing the rate of thermal transfer. Conversely if you speed up the flow, the water stays cooler because it is not close to the heat source for as long. The rate of heat transfer from the water at a radiator or into the bucket of water is increased by the water getting hotter but it does not fully offset the added thermal load from the smaller flow. The water will go up in temperature fast at first and then the rate of increase will slow or even stop. That is due to these effects. As the water temperature increases it picks up less heat but discharges more in the radiator. That slows the rate of increase. If you continue to think faster flow does not reduce the maximum temperature it would be easy to test. I am confident you will find that a bigger pump - more flow - will reduce the temperature. There are limits, of course, if the water flows too fast you can impede heat transfer because of turbulence at the water to metal interface. But within reason, more flow = lower temperature.

I thought of a common situation that may help convince somebody of the effect of flow. My convertible has an electric water pump. It doesn't have a temperature gauge but I run software on my phone and tablet called "torque" that lets me monitor all the data on the OBDII port. I've monitored engine coolant temperature and I can clearly see when the coolant pump is running at maximum speed. It's a BMW and they let the coolant heat up pretty high if you are just cruising along. But if you get on the engine, it drops the coolant temperature. The heat input is increased as you accelerate but that is more than offset by higher coolant flow.
 
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When was the last time you cleaned the air filters, or replaced the tampons? Also, I noticed you have several several filters inline. The more filters you have for the air to pass through the harder the compressor will have to work. Each filter creates resistance and back pressure. This will cause it to run hotter. I also noticed in the picture of your setup that you are using some copper lines that are smaller in diameter than the main silicone tubes. This will restrict you flow and as a result less fluid per unit of time will come in contact with the surface area that needs to be cooled. Cooling is proportional to to heat transfer rate and cross sectional area of the tubing and the area the Cooling fluid passes through. Also, run 50/50 distilled water to aluminum safe coolant. The coolant has lubricants that help with the conducive heat transfer. Your setup should not be running at 70C. At most 57C. If all that is taken care of and you are still running hot, your problem is with the compressor itself. Just my two cents worth...
 
The suggestion that moving the water faster does not improve heat transfer from the YH is untrue. The rate of heat transfer is a function of the temperature difference between the higher temperature source and the lower temperature destination for the thermal energy. If you slow down the water flow, it spends more time close to the source of the thermal energy so it gets hotter reducing the rate of thermal transfer. Conversely if you speed up the flow, the water stays cooler because it is not close to the heat source for as long. The rate of heat transfer from the water at a radiator or into the bucket of water is increased by the water getting hotter but it does not fully offset the added thermal load from the smaller flow. The water will go up in temperature fast at first and then the rate of increase will slow or even stop. That is due to these effects. As the water temperature increases it picks up less heat but discharges more in the radiator. That slows the rate of increase. If you continue to think faster flow does not reduce the maximum temperature it would be easy to test. I am confident you will find that a bigger pump - more flow - will reduce the temperature. There are limits, of course, if the water flows too fast you can impede heat transfer because of turbulence at the water to metal interface. But within reason, more flow = lower temperature.

I thought of a common situation that may help convince somebody of the effect of flow. My convertible has an electric water pump. It doesn't have a temperature gauge but I run software on my phone and tablet called "torque" that lets me monitor all the data on the OBDII port. I've monitored engine coolant temperature and I can clearly see when the coolant pump is running at maximum speed. It's a BMW and they let the coolant heat up pretty high if you are just cruising along. But if you get on the engine, it drops the coolant temperature. The heat input is increased as you accelerate but that is more than offset by higher coolant flow.
We are both saying the same thing differently. I agree with you thoughts. Hopefully someone will listen...
 
Cooling is proportional to to heat transfer rate and cross sectional area of the tubing and the area the Cooling fluid passes through. Also, run 50/50 distilled water to aluminum safe coolant. The coolant has lubricants that help with the conducive heat transfer. Your setup should not be running at 70C. At most 57C. If all that is taken care of and you are still running hot, your problem is with the compressor itself. Just my two cents worth...
The bolded part is incorrect. Pure DW actually removes heat better than a 50/50 antifreeze mix. The only reason for the antifreeze is to 1) Keep the water from freezing, and 2) To add anti-corrosive properties to protect the aluminum.

In fact, a 90/10 or 80/20 mix of DW/AF would cool better, but of course wouldn't protect to as low of a temp as the 50/50 mix would.
 
The bolded part is incorrect. Pure DW actually removes heat better than a 50/50 antifreeze mix. The only reason for the antifreeze is to 1) Keep the water from freezing, and 2) To add anti-corrosive properties to protect the aluminum.

In fact, a 90/10 or 80/20 mix of DW/AF would cool better, but of course wouldn't protect to as low of a temp as the 50/50 mix would.

I hear what you are saying and I agree about the water by itself. However, there are disadvantages of only using water.

To clarify I use the Prestone 50/50 ready mix. Fill half the bucket with this 50/50 antifreeze/coolant and the other half with Distilled water. So, in reality it is somewhere in the range of 75/25 antifreeze/coolant to Distilled water. I used distilled water for six months and then opened the cooling jacket to clean it and I did not like what the DI water did in there, thus my choice to add antifreeze/coolant in the water. This mixture has other additives that increase cooling and protection to the metals (corrosion, buildup, pitting, scaling, rust). I have not had any problems ever since and have been using the same fluid for the last 3 years. It is clean, it keeps things clean, and does the job without question. I use this fluid mix for my Tuxing double cylinder and Yong Heng. Just my thoughts and my first hand encounter.

With that said, it works for me. We all do what we believe is right for our situation.

Click the link below for:

Presotone Antifreze/Coolant mixture
 
I hear what you are saying and I agree about the water by itself. However, there are disadvantages of only using water.

To clarify I use the Prestone 50/50 ready mix. Fill half the bucket with this 50/50 antifreeze/coolant and the other half with Distilled water. So, in reality it is somewhere in the range of 75/25 antifreeze/coolant to Distilled water. I used distilled water for six months and then opened the cooling jacket to clean it and I did not like what the DI water did in there, thus my choice to add antifreeze/coolant in the water. This mixture has other additives that increase cooling and protection to the metals (corrosion, buildup, pitting, scaling, rust). I have not had any problems ever since and have been using the same fluid for the last 3 years. It is clean, it keeps things clean, and does the job without question. I use this fluid mix for my Tuxing double cylinder and Yong Heng. Just my thoughts and my first hand encounter.

With that said, it works for me. We all do what we believe is right for our situation.

Click the link below for:

Presotone Antifreze/Coolant mixture
Correct. DW alone is bad for aluminum. And it freezes. But AF reduces cooling. So it's all about trading off. Personally, I use Water Wetter instead of AF, because I can use a LOT less and get the same corrosion protection, but I also don't have to worry about freezing.

The truth of the matter is, as cool as my CS4 runs (and most of our compressors on here do), we could likely run 100% AF and be just fine. Probably wouldn't change the temp by more than a degree or two. We don't have to worry about boiling nor hot spots within our coolant systems.

My point about AF is that it doesn't cool better than water alone. But it's necessary to use it or WW to reduce corrosion as well as algae in our systems. I don't have the desire to do so, but maybe one day someone will run pure AF in their coolant system and report back as to the cooling performance and what the system looks like in a year or two (probably sparkling clean would be my guess).
 
I'm just sharing information I gained from many years of building high end water cooled gaming computers. You can't compare the simple cooling of a yong heng compressor to your car because the compressor doesn't produce enough heat to boil the coolant where your car does. I can tell you a half gallon per minute is plenty of flow on a closed loop with radiator for these compressors. Even if you double the flow each molecule of coolant spends the same amount of time being heated and cooled.
If flow is high enough to cause cavitation at a heating or cooling interface it would be detrimental due to loss of contact but having enough for impingement at the interface helps a tiny bit through increased contact. In the case of these yong heng compressors the limitation is lack of contact area with the heating side. The heat cannot get into the water fast enough.
If you measure temperature at the inlet and outlet on the head you'll see the coolant barely picks up heat when it passes through.

To greatly improve cooling, remove the second stage cylinder and make the water passage wider without getting too close to the bolt holes on each side or getting closer to the cylinder bore. Just make it wider and you'll have many times the heat transfer area. Do not open the gasket hole.
I don't think the cooling on mine has a small coolant passage like in your drawing, mine has a water jacket like this one in the pictures. I took these screenshots from a video on YouTube. Here's a link to the full video:

Screenshot_20240414_044340_YouTube.jpg

Screenshot_20240414_044308_YouTube.jpg
 
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