Hong Yeng

[Rodeo]

+1 to what Eaglebeak said. The name "Yong Heng" gets used a lot to cover all the similar clone units. The true Yong Heng's have the name on the side on the compressor. I went with the step up from the basic unit. I've seen it referred to as "Hardback". It has the moisture traps after the first and second stages. I went with the manual shut off for three reasons. 1- I am not going walk away while it is running. 2- It is a best practice to relieve the pressure on the unit (bleed the air) before turning it off and to start it with the bleed knobs open. 3- Price. 

 

[airgunfans]

About to order the Yong Hong compressor and filters from amazon. I noticed a couple different YH compressors, one says standard, the other "set pressure" ?

Is one preferred over the other. The compressor stage chambers even look different.

I have got the version with automatic cut off at the preset pressure. Just to be safe, I don't want to stay close the compressor when it is running so it must turn off by itself. It seems to be over worrying now but that was the reason when I ponder over which version to get a year ago. There has been saying that stopping the compressor while it's under load may cause damage but I can't figure out why it is so.

BTW, make sure that the Yong Heng you buy is equipped with the new-version first-stage piston which has got a much thicker top. Cracking of the top has be reported to be a rather common problem. 

 

[Bowlead]

Of all the Yong Hong s I views on Amazon, I didn't find any noted with the new version first stage piston. Is there a notation specific to a newer model I'm missing?

Really appreciate your input.

Thanks, Terry

 

[airgunfans]

Is there a notation specific to a newer model I'm missing?

I afraid there is not any. You may try to ask the seller who probably doesn't know as well but they should be able to check with the factory. 

 

[Rodeo]

I read somewhere (I think on another thread in this forum) that the change to the new version pistons happened at the beginning of this year. No torches and pitchforks if this is not 100% accurate. Lol

 

[airgunfans]

I read somewhere (I think on another thread in this forum) that the change to the new version pistons happened at the beginning of this year. No torches and pitchforks if this is not 100% accurate. Lol

I think you are referring to this one : https://www.airgunnation.com/topic/yong-heng-piston-cracking-no-more-hopefully/

 

[USAFANG6799]

Man that is great! I have one I had to rebuild twice? Question is, what temps are you running? Are you putting ice in the water? Just curious, knowing that heat is our enemy, I have 15 min max before I am at 65 c. Thanks

Are you using something large enough like a 5 gallon bucket of water?

When the pump is on does it look like ample water is coming out oh the hose?

Make sure the flow intake on the pump is not closed or just partially open.

Sounds like you are not getting enough water flow. 

How warm of an area are you operating it in?

Check to make sure the cooling fan in the rear of the unit is working properly. 

Keep us informed. 

 

[vinny]

temp after 15mins topping off tank

 

[Rodeo]

42.2°C after 15 min run. I use Royal Purple oil and run it in my basement which stays at a pretty consistent 70°F. I have a small 6" fan that blows onto the compressor head. I use a 5gal bucket for the water reservoir. I put a good sized block of ice in it and use a couple of frozen water bottles. I weighted the water bottles with rocks so that they sink in the bucket (no surface area out of the water). I also position the return water line so that the warm water flows over the block of ice.

Sinking the frozen bottles seems to help the unit run about 2°C cooler.

 

[steeve]

I think you guys are a bit over concerned about the cooling temps. and comparing to others is not helpful unless you state the ambient temps you are working with. in the So Cal desert here, both of mine ran at over 65C and one accidentally got up to 120C once when the cooling hose got pinched shut. the summer temps in my shop get over 95F and even with the cooling bucket full of ice, head temps get over 60C in less than 10 minutes......just filling up the water separator cylinder (about 2 minutes), gets the temps over 55C. these temps are really not very hot when you consider that 4 stroke gas engines run 200 to 220F cooling temps.

As far as the burst discs go, I have blown a few. they will not hold over 4,000 psi on my unit.....then I might be torquing them too tight. this is my second Yong Heng; the first was a manual shut off, 220 volt model, which is cheaper to run than the 110 volt ones, because they use less amperage. it ran well for the short time I had it, but I lost it when my home burned down a couple years ago. my second one was also a 220 volt, but I made the mistake of getting the auto shut-off model; it would stall and ran intermitently, making me think it was seizing, but it was fine inside and the problem was a bad relay for the shut-off feature was cutting out. I just removed it and bypassed the auto-shut-off feature. I found out that the the cheap relays were a common problem, from brand new. Anyway, even with just 4 bottle fills on my current compressor, i consider it paid for, considering how far I have to drive and how long I have to wait, to get my tanks filled otherwise. If my Yong Heng blows tomorrow, I'll just buy another; I spend more money on one grocery trip!

 

[Rodeo]

Steve, From what I have read it seems that the general consensus is "the lower the operating temp the better" and cooler running temperatures go a long way toward longevity of these YH compressors. So no I do not believe that we are "overly" concerned about it. Also, I did state the ambient temp that I am operating the unit in. I see these posts as a sharing of information - Vinny did this and this was his result - I did that and that is my result. It is a way to collect info so that the community can form a basis for best practices. Now we have your input to add to the knowledge base. Thank you.

 

[Eaglebeak]

IMO these pumps are like any other water-cooled piston engine and should be engineered to run best at their ultimate working temperature. Running an engine to cold will do far more harm than running a bit hot because the tolerances in a cold motor are too tight and wear is accelerated. Using ice is a bad idea because chilling a hot cylinder housing can cause uneven heat distribution and the possibility of warpage or seizure. The thermometer probe on these things measures the first stage cylinder head, not the temperature of the coolant. So if you are getting a reading of 65 degrees at the head, the coolant is probably only 45-50 max. If you don't believe me, put your hand under the output hose. If it doesn't burn your hand it is not hot enough to be at a good working temp. Why do you think cars have thermostats? It's not as somebody else stated to give the coolant more dwell time to take more heat from the engine, it's to allow the motor to heat up as fast as possible and keep it in the optimum heat range. As for worrying about moisture diluting your oil. If you run the thing for longer and let the oil get hot, the moisture will evaporate off as it does in a car. Would you rather buy a car with a 100,000 miles on the clock that had been driven at 70 MPH on the highway doing interstate trips or one with the same millage but only driven to the local store and back at 35 MPH. I know which one I would be laying my hard-earned on. I run my YH pump with the supplied water pump and a couple of gallons of tap water, use generic mineral-based compressor oil which I will never change because I don't expect that it will do fifty hours without some sort of rebuild and it works just fine. The thermometer rises quickly to about 50-55 degrees and stays there no matter how long I run it for which is usually no more than 25-30 minutes to top off a 6.8-litre bottle. The general consensus becomes gospel when somebody gives a theory that a few uninformed readers follow and it becomes compulsory for newbies seeking advice from the pages of a forum. Sorry for the diatribe but reading misinformation ad-nauseam motivated me to challenge some of the bunkum that has become accepted as fact.

 

[steeve]

I agree with eaglebeak on almost every point. and he brought up a popular myth that I saw subscribed to here; Reducing the coolant flow does not in any way promote cooler running temps. Just the opposite is true. any observations or tests indicating otherwise are flawed. If the object is to reduce component temps, then more, and subsequently faster coolant flow through the cooling jacket and any associated heat exchanger is more effective in obtaining component heat reduction. The reason being is simply that heat transfer between the coolant and the heat source is greater with higher flow volume, because the temperature differential at the contact point will be greater. you can not have a pump that moves to much water.

engineering by "consensus" is always the last resort, and should only be done when there is no science available. Secondly, consensus is how myth and superstition propagates. 

 

[Rodeo]

Wow talk about misinformation. These pumps are NOT like any other water cooled engine. You compare a compressor to an internal combustion engine - the only similarity is that they both use pistons. I agree that designing them to run at their max operating temp would be ideal. We have compressors on the market that are designed to do just that but we buy these Yong Hengs for far less than the $1300.00 and up for those units. As far as running these units too cold: 42° C is about 107°F? Running well above normal room temperature is too cold? "Using ice is a bad idea because chilling a hot cylinder housing can cause uneven heat distribution and the possibility of warpage or seisure". That is why there is a pump to move the water. Its not like someone is running the unit until it gets hot then dousing it with ice water. If this point was valid then it would apply to plain tap water as well. Yes, the return water on my unit is cool enough to put my hand in - that is a good thing. Compressors unlike car engines do not need to "warm up to operating temp" to perform well. This is only true in EXTREMELY cold environments. The compressor/car analogy is simply not a good comparison and neither is the 100,000 mile car analogy. It is great that you can run your unit for 30 min and have the temp stay at 55° and not go over the manufacturers listed max of 65°C. I have seen posts of others setting up cooling systems using computer cooling fans, running water straight from the tap into the unit and using very large water reservoirs to avoid using ice. Yours is the first I have seen that can suffice with just a couple of gallons of tap water for extended run times. Guess the majority of Yong Heng users have been doing it all wrong.

 

[Rodeo]

Maybe consensus was not the proper word to use. How about "the methods found to be effective thru experimentation and agreed upon by the majority of individuals that have tried said methods".

 

[Eaglebeak]

I believe that the majority of users just stick to the instructions. My comparison with a piston-driven combustion motor is valid from an engineering point of view as they are very similar, only the compressor doesn't have to deal with the extra issues caused by combustion. If you believe that the thermostat is only useful for cold conditions, you have no grasp of simple mechanics. The operating temperature of the coolant in an internal combustion engine is about 180 F or 80 c. Try putting your hand in that. You ask that running at room temperature is too cold. I say yes for continuous operation it is too cold. What I mean about the return flow being relatively cool, is indicating that the cylinder is under its safe heat range or the coolant is not doing its job of pulling the heat out. If the temperature was dangerously high, the return coolant would be boiling or turning to steam, similar to an overheating combustion engine.

 

[airgunfans]

Running an engine to cold will do far more harm than running a bit hot

The water flow in YH is for cooling the second-stage cylinder only. This part has got plastic piston rings instead of steel rings like those in car engine so I think what's applicable to car engines may not apply on YH. I connect the water hose of my YH to the tap and the temperature never went beyond 50 degree Celsius. 

 

[steeve]

Yes, I agree that IC engine comparrison is not the best comparison in this case, but anything less than coolant boiling temperatures should not be an issue. If the rings are indeed plastic, they are surely a high temp type, since mine are still working. As far as following factory operating "instructions" goes, this is the first I have heard of any. There were certainly none included with either of my Yong Hengs. Both of my compressors run/ran at 65C if they were on more than 15 minutes and that is with a lot of ice in the water plus an auxiliary fan blowing point blank on the compressor top. The only difference in my case being the summer ambient temps in the shop averaging in the high 90s F. But in the winter, when it gets down below 60F the pump still runs over 55C; Probably just the weak aquarium pump that is supplied or maybe a poorly calibrated temp sensor. Regardless, I have seen no ill effects, especially since my second compressor has run well over (200F), for a brief period. I am considering buying another Yong Heng and hooking them up in tandem, to push air through the same dryer, and use the same cooling reservoir. This would reduce fill times to half; good for when I shoot my air gobbling semi-autos and Quack 50.. That would still be way cheaper than any other compressor I know of. 

 

[Eaglebeak]

Running an engine to cold will do far more harm than running a bit hotwater jacket

The water flow in YH is for cooling the second-stage cylinder only. This part has got plastic piston rings instead of steel rings like those in car engine so I think what's applicable to car engines may not apply on YH. I connect the water hose of my YH to the tap and the temperature never went beyond 50 degree Celsius.

I agree totally about the water-jacket cooling only the second stage. That is why the temp reading taken from the first stage head has little relevance to what the actual water temp or how hot the second stage cylinder is. The only way of knowing that is knowing how hot the water coming out is. I am arguing that if that water isn't hot enough to burn your hand then it won't be hot enough to cause any damage. I'm not saying that cold water will cause damage but it is more likely than running at the temperature that it is designed for. What I am really trying to say is forget the ice, it's false insurance. If the water in your bucket gets hotter than 60 C, get a bigger bucket.

 

[steeve]

The water temp in the bucket has little to do with the actual temp of the piston and cylinder at any given point. it is more a function of how long the compressor has been running and how well the water is able to remove the heat from the aluminum second stage cylinder assembly. The water contact area in the Yong Heng water jacket is comparatively small, due to manufacturing constraints and therefor heat transfer is poor but still adequate. ice in the water bucket may not be necessary, but in my hot ambient temps, it does help to reduce operating temps. without any factory information, there is only one way to find out how much heat this compressor can stand and that is to test it at increasing heat levels until failure. I don't want to do that unless someone gives me a free unit to to test. I can tell you this; 65C is not excessive from my experience.