Black Yong Heng oil

That's some fine "cooling mod" work you did but I have a question. With the time you invested in cooling off the water return (back into water reservoir) do you think your water going into the compressor would be any cooler than MY water? I keep 2, .5 gallon plastic milk jugs full of water, frozen solid in my freezer & drop into bucket when I run the compressor. I'm willing to bet that after all that work you invested in cooling your return water it's not any cooler than mine going out (to compressor). Only takes me a few seconds to drop my "ice blocks" into the bucket or return them to freezer. You did NICE WORK but was it worth time & mat'ls invested?
using the cool can filled with ice my water temp stays at 62 -65 degrees for 1 hr that's why i used a cooler for the coil also water wetter does wonders for transferring heat
 
That's some fine "cooling mod" work you did but I have a question. With the time you invested in cooling off the water return (back into water reservoir) do you think your water going into the compressor would be any cooler than MY water? I keep 2, .5 gallon plastic milk jugs full of water, frozen solid in my freezer & drop into bucket when I run the compressor. I'm willing to bet that after all that work you invested in cooling your return water it's not any cooler than mine going out (to compressor). Only takes me a few seconds to drop my "ice blocks" into the bucket or return them to freezer. You did NICE WORK but was it worth time & mat'ls invested?
thanks it took a little time to do but keeping the cylinder temp down and cylinder head temp is key
i have another cylinder that i am making water cooled so it will a water-cooled cylinder and head next month
i have a few cylinders done with different water jacket designs i also have a PC water chiller i used to have on my gaming pc that will keep water temps to 60ish with no ice
i like to tinker ive raced drag cars for 20 years dirtbikes atvs and now into the pcp guns and 4wd atvs its all about having fun and enjoying life
if anyone can benifit from these mods have at it dont mind passing ideas
 
I always wondered why they recommended non detergent oil over a good automotive Oil?

🪰Fly
Motor oil detergents suspend particles so they can be trapped in an oil filter. Since there is no oil filter in an air compressor, detergent would keep the particles circulating which would cause premature wear of the rings and pistons.
 
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i just made a simple cool can with 1/4 copper tubing and a 1/2-gallon igloo round cooler full of ice
put it on the return line and it cools the water going back to the 5-gal tank
i also wrapped all 3 high pressure lines their water cooled as well.
i can run this compressor 1/2 hr=40 min and keep temps to 45c usually fill 1 1.6l bottle at a time
1 also added a 8 in 480 cfm cage fan keeps the Elec motor and electronics cool as well.
i use royal purple (been using for 20+ years in my drag cars no issues) i also added an hrs. meter and change the oil every 3 hrs. of use

88turbocoupe,

At this point you might as well run another copper line in the cooling tank and connect it to your intake, the chilled copper line should condensate any moisture going into your pump, to reduce your need for a post filter. :unsure::unsure::unsure:

Smitty
 
88turbocoupe,

At this point you might as well run another copper line in the cooling tank and connect it to your intake, the chilled copper line should condensate any moisture going into your pump, to reduce your need for a post filter. :unsure::unsure::unsure:

Smitty
i have a water filter housing filled with beads connected to the intake of the compressor. that made a big difference in moisture along with cooling the lines slowing the water circulation down through the cool can and back to the tank as well comes into play can't cool with water gushing through it.

20240727_205448.jpg
 
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thanks it took a little time to do but keeping the cylinder temp down and cylinder head temp is key
i have another cylinder that i am making water cooled so it will a water-cooled cylinder and head next month
i have a few cylinders done with different water jacket designs i also have a PC water chiller i used to have on my gaming pc that will keep water temps to 60ish with no ice
i like to tinker ive raced drag cars for 20 years dirtbikes atvs and now into the pcp guns and 4wd atvs its all about having fun and enjoying life
if anyone can benifit from these mods have at it dont mind passing ideas
I know how heat can kill a compressor. I have a double fan oil cooler/radiator blowing on hp cylinder that I decided to try a couple months ago & haven't moved it since. With fans blowing back & front & iced water pumping through, my cylinder head temp hasn't gone above 53 Celsius, even on a long run (20 minutes).
 
I keep mine iced as many of you with head temp reporting no more than 55C. My oil turns black while others do not. I think we can all agree is that head temperature is the key. I'm good with this as I cannot control Chinese Quality control across the board, or the true accuracy of the cheap temp sensors included with each kit. Mine does agree very close to my Fluke temp probe when first checked 4 years ago.

I also had a bad check valve o-ring two years ago so already removed the SS lines, cleaned threads to avoid any hint of cross threading and checked for fit. All rebuild parts accounted for that came with pump but ordered the reed valve just in case.
 
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About heat on cylinder heads...here are 3 readings on a freshly rebuilt first+second stage from a kit. The pressure is about 250 bars in this picture after some 15 minutes run time.

20240522_122117.jpg


The Temp #1 probe is attached to the most highest point on first stage = low pressure cylinder ribs deep to the main body;
The Temp #2 probe is attached to the most highest point on second stage - high pressure cylinder - cap;
The YH Tamp sensor shows the water flow.

Temp sensors.JPG


I just feed the bucket continuously from a garden hose in my garage and the overflow is a collateral damage ;) .
 
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About heat on cylinder heads...here are 3 readings on a freshly rebuilt first+second stage from a kit. The pressure is about 250 bars in this picture after some 15 minutes run time.

View attachment 488297

The Temp #1 probe is attached to the most highest point on first stage = low pressure cylinder ribs deep to the main body;
The Temp #2 probe is attached to the most highest point on second stage - high pressure cylinder - cap;
The YH Tamp sensor shows the water flow.

View attachment 488298

I just feed the bucket continuously from a garden hose in my garage and the overflow is a collateral damage ;) .
That motor gets blazing hot, no? I have been using a big box fan to force and cool whole unit including clamp on fins on SS tubes instead of wrapping with copper. Makes easier for any work needed.

I really like the flow rate on these pumps vs the slower $500 CS4 when filling tanks! Long term rebuild is easy on the YH if you don't kill the motor.
 
That motor gets blazing hot, no? I have been using a big box fan to force and cool whole unit including clamp on fins on SS tubes instead of wrapping with copper. Makes easier for any work needed.

I really like the flow rate on these pumps vs the slower $500 CS4 when filling tanks! Long term rebuild is easy on the YH if you don't kill the motor.
thats why i used a 8 in grow tent fan it moves 480cfm and is adjustable and whisper quiet
 
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I use Nuvair 751 lubricant in my Yong Heng and have for the 3.5 years I've owned it. I change it once a year which is well under 10 hours of run time for me. So maybe I'm changing it really early but I don't care. I use full synthetic in my vehicles and change it every 5000 miles. Oil is cheap. The oil comes out dark colored and I do not care. The oil from my vehicles comes out dark too and I do not care about that either. One of the purposes of oil is to transport carbon out of the device it serves.

My cooling bucket contains contains water with water wetter added which aids cooling and also allows me to just leave it in the bucket - it doesn't allow mold or algae growth. The water visits a small computer radiator (same line size as the Yong Heng) with a couple fans on it. I added a small 8 inch fan blowing across the YH motor too to aid cooling. I can fill my 45 minute (6.8 liters or 66 cubic feet) bottle from 3200 to 300 bar in under half an hour without exceeding 60 C but I need a couple pop bottles of ice added in the summer. Without the ice the temperature won't go over 62 C. I don't do anything about the temperature of the lines, I just avoid touching them until they cool down. The YH resides in an unconditioned room off of my garage.
 
Hey JimD, yeah, many have been blessed by the YH SS lines, no? My coalescent filter does a fantastic 1st stage job for water removal, or I would be spending way more effort in cooling those SS lines as in low pressure shop compressors.

I have several old transistor cooling clips, old work stuff, that I do use other than sit unused. Just a gesture other than any solution. I would like to see a large coiled SS final loop but my SS tube bending skills are lacking. My old valve packs used in our deep water ROVs were a work of art...by our shop techs. Nuvair 751 is also on my short list after rebuild.
 
I use the Seco 500 from the beginning. It turns black quickly. I have seen the Seco used in scuba compressors and it turns black there also. I think it normal.

My YH has never gotten hot. I shut down around 115F if it gets there. Ice blocks in the water container, I can fill my 45cf scba tanks before reaching my imposed critical temperature.
 
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I use the Seco 500 from the beginning. It turns black quickly. I have seen the Seco used in scuba compressors and it turns black there also. I think it normal.

My YH has never gotten hot. I shut down around 115F if it gets there. Ice blocks in the water container, I can fill my 45cf scba tanks before reaching my imposed critical temperature.
Yep, many turns black and some says not. Curiosity gets me every time. High secondary temperature no matter what your water flow is? I might have pre-toasted mine first using RP gear oil and or have build up of deposits using antifreeze with always distilled water? I might flush with Husky Syn just to see if mine likes it before next rebuild. As before, Seco turns clear if you let it sit, which I poured off leaving the carbon (?) sludge to wipe up.
Shame that the Yong Heng of many makers could not respond with other than the initial incorrect AW oil...crickets.
 
so far i have filled my tank 10 times small tank 1.6l to 4500 lbs
changed my oil after the first 1/2hr run time with royal purple been using this in my industrial screw compressor for years never had any issues.
temp definitely plays a roll....... water flow to fast it won't cool... to slow it runs hotter
just like using water with antifreeze it runs hotter by 20 degrees
distilled water with redline water wetter 20 degrees cooler.
i run mine for roughly 1/2 hr. 40 min tops never exceeds 45C cyl temp stays between 130-135 degrees head temp between 82-98 degrees
using the home made (cool can) be full of ice does 2 things 1 slowed the water down and 2 is cooling the water going back into the tank
that was a win win these compressors have an operating temp so to see cyl temps between 130-160 isn't out of the norm
cooling to much can also cause problems so id say if you're up to 45-50c your fine

as far as all these different oils whatever works for you some have good luck with the mobile as well.
 
Interesting you mentioned screw compressors, yours is oil bath? Seen lots of these on the Rigs making high volume 400 psi air for the drill floor. Lots of buckets of Mobil compressor oil laying around but nothing on my favorite internet oil. Whatever the rig pays for right?

I have not seen any major cooling drops while using water wetter but then I'm still using the old stinky stock water pump. I'm looking to reduce the amount of white corrosion build up inside the top water chamber as shown in Cottons old video.

So, is anyone showing always black oil using stock pumps? I never measured my water out temps but the iced water is warmed up on the return flow back to bucket. I never let the temps get over 56C as the pamphlet shows max of 70C which most thinks is too warm. Putting all the threads together we would all see blackened oil after 50C? Cheers
 
My thought s are the oil turning black would be carbon deposits. I know these oils are non detergent but
even so non detergent oil in a automotive engine turns black also. I will continue to change my oil when
it turns black. I,m trying out a synthetic oil that a ISO 100 oil that seems very promising. I have been using
Royal Purple & been happy with it. This oil is clear with not dye in it as RP seems to have, & I like that for
it is easier to check. I,m trying to get a guy on the net that’s a oil exspert on oils to do his show around these
oils. It he indeed does I will keep you up to date. The oil I,m trying now is TriboDyn synthetic no- detergent
ISO 100 which is a 30 weight. ISO 100 30 wt seems to be what everyone seems to think is what to use now
instead of the ISO 46 or 20 WT people were using in the past it seems.

Just my two cents. 🪰Fly
 
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Mine turns RP black as well, the oil I first tried. I sent pictures on an old thread after 20 minute run. Yes carbon, my best guess, will settle out to clear. I could go try to send 33F water to the head without locking up the top piston? Kidding, not worried as pump still makes good pressure. The side check valve seal being my only issue so far. I'll wait for fall months for a look into the top piston and check seals.

As for oil, lots settle on oils for HP air compressors, not shop compressors with max temp rating. Sofar a few of us have managed to turn Seco 500 black but others not. High head temps, mine 56C (indicated) would be a good guess?
 
Carbon deposits would require combustion from a fuel source if I understand how they work correctly...If you're experiencing a lot of detonation I could see this but I find this rather unlikely...and detonation would be quite destructive and audible imo.

Wouldn't it be more likely oil turning black is from oxidization or soot and impurities from internal surface wear?