Best oil for Yong Heng compressor?

I agree; do not use the manufacturers recommended #46 hydraulic oil, it will cause accelerated wear. Do not use motor oil either, it can detonate when it gets past the piston rings into the pressurized air supply....just look at your down stream air filter element after some use and you will see the oil on it; the combination of high pressures and motor oil are dangerous.. I bought some of the Royal purple compressor oil, but I see that it really is purple and as such, you can't tell when it gets dirty. so, next time I will get a "clear" synthetic compressor oil. These Yong Hengs have borderline engineering, with no shell-bearings or bushings in the connecting rod and no oil pump either; the aluminum rod runs directly on the crank pin and wrist pin, plus it has high bearing speeds;(RPM x journal circumference), not a combination for long life. So run the best high pressure compressor oil you can find and change it often; you could double or triple the life of your Yong Heng.
 
Steeve the Yong Heng has the same connecting rod set up as your lawn mower with 1500 hours running strong. See my thread "dang yong heng". There you will find good clear pic's of the big end rod bearing and crank surfaces on a ran hard put up wet Yong Heng. I run 10w-30 cheap azz quakerstate motor oil, many hours of run time.


Your second stage piston most likely broke from detonation of the motor oil which occurs btdc.
 
Going to buy a youg heng compressor and been doing some research on the oil to use. I think I'm going with the Jenny Ultimate Blue Synthetic Oil 20 weight this is cheaper than the royal purple which is 30 weight and flash point of 470 the Jenny has a higher flash point of 507 and beats in the Royal purple in the specs I have researched. I seen people are using Hydraulic oil. Here is what I have found look at the picture of the weight of 46 hydraulic oil and the flash point. What's of through?
1582915042_12019795975e595de24b62f4.49942761_NEW Hydraulic- AW Hyraulic Oil Specs.png

 
The YH rod is not much different than what is on large gasoline model airplane engines and wackers which run with very little oil compared to the YH which basically has an oil pool.



Just change the oil regularly and use a good moisture filter on the output.

later on order a spare complete piston with rings($25) for when the high side rings wear eventually.
 
Not sure about the mineral oil. The standard motor oil would probably be fine for the rod to crank interface but standard thought is that petroleum products and HPA are a bad mix due to potential detonation. Surely the possibility exists for vapor, if not actual oil volume, reaching the high pressure area on these compressors. I use HPA compressor oil for that reason.
 
To all newbies and users of inexpensive Chinese compressors, please consider. Those two page Chinglish manuals that accompanied your compressors were written by non-English speaking writers and their terminology doesn't translate literally. Instead of a "burst disk" they say "explosion proof safety device". Instead of non-detergent high pressure compressor oil, they substitute #46 hydraulic fluid.

Centercut, Brian 10956, T3PRanch, and JimNM are experienced compressor owners and know what they are advising. If you are spending good money for a compressor which is being pushed to it's limits to produce 4500 psi air without breaking, why would you not buy insurance using quality oil? The biggest owner error posted over and over on these forums is owners trying to save money by using #46 hydraulic fluid because the Chinglish owner pamphlet says to. DON'T. That's why the exhaust stinks, the fluid turns black in an hour, and the little compressor needs replacement parts. Motor oil is as bad for compressors as hydraulic fluid. Unless you buy NON-detergent synthetic oil, motor oil leaves burnt residue in check valves and prematurely wears out the plastic resin piston rings. I've rebuilt compressors for guys who were getting black goo out of their bleeder valve and pressure wouldn't build as fast as the temperature rose.

Use a premium high pressure compressor oil. What you spend on oil will be saved on fewer repairs. There are many choices of high pressure compressor oils I use Chemlube CF500 from Filtertechs.com. I've owned 4 oil filled compressors over 14 years with no failures. This oil costs me $15 a quart and is changed annually. One quart of oil provides two oil changes on my dive compressor but 3 on a Yong Heng. Isn't your Yong Heng worth protecting annually for 1/3 the cost of a tin of pellets? It makes no sense to me to pay $15 for 100 FX slugs yet balk at the cost of 3 oil changes for the same $15 expenditure. 

The alternative is to save a few dollars, breathe in the stench of burnt hydraulic fluid and keep the vendors on Aliexpress happy with repair parts sales. After all, the manual says so. Would you clean your PCP with Hoppe's #9 if you knew it degraded the o-rings? Of course not. Why shorten the life of your compressor using motor oil or hydraulic fluid to save five bucks a year? An ounce of prevention is worth a pound of cure.
 
This appears to be an oil that has it's main advantage in starting/operating well during extreme cold weather. but in the day time, it never gets below freezing around here; much more importantly to me is if the oil is transparent (not black or purple), so I can tell when it gets dirty by looking through the sight-glass. I looked everywhere for this info but found no reference to Powermate's opacity or color, so unless I find out, I am not going to order it for my compressor. In the So Cal desert we have the opposite weather problems with our compressors overheating. In the 15 minutes it takes to fill my dryer-canister and gun reservoir, my Yong-Heng gets up to 62-67 degrees C and over 80 degrees C, if I try to top off a medium bottle to 4,200 psi. I don't do that anymore unless it's wintertime when we can get a cold night in the 40s and use ice in the coolant bucket with an auxiliary fan on the compressor.

So if anyone knows if that Powermate synthetic is transparent, please let us know, and I will gladly switch over from that purple stuff that looks dirty from the get go.
 
@T3PRanch, @Humdinger, and others nailed it--use an awesome oil for long life. The top end is water-cooled, the bottom end is...not cooled at all! The oil is getting cooked so use oil that can take it!

Just tore down a new, never-used new-in-the-box Yong Heng compressor from Yong Heng:

Low and high-pressure pipe hole threads weren't tapped well, so the stainless fitting threads cut themselves a path and pushed chips into the cylinder. To help matters get worse the air/oil separator parts were at the bottom of the housing--never having been assembled! Just sitting there, like the starter capacitor is (it lays on the motor unsupported, also getting cooked). The start of all this tear-down is the high-pressure manifold block was never fully tightened and flopped around, which was the first red flag. That made me curious what condition the one-way valve that sits in that block was in (it's fine). Finding the unsecured capacitor lead to the tear-down of the rest of the block, leading to tear-down of the head, leading to...

So USE Seco Lube 500 | SYNTHETIC CL-581815-LQ @T3PRanch linked to!

IMG_20210117_190457.1610986249.jpg

Hmmm...not supposed to be sitting on the bottom....


IMG_20210117_190337.1610986219.jpg

IMG_20210117_194346.1610986422.jpg

That doesn't look right...lovely...
 
To all newbies and users of inexpensive Chinese compressors, please consider. Those two page Chinglish manuals that accompanied your compressors were written by non-English speaking writers and their terminology doesn't translate literally. Instead of a "burst disk" they say "explosion proof safety device". Instead of non-detergent high pressure compressor oil, they substitute #46 hydraulic fluid.

Centercut, Brian 10956, T3PRanch, and JimNM are experienced compressor owners and know what they are advising. If you are spending good money for a compressor which is being pushed to it's limits to produce 4500 psi air without breaking, why would you not buy insurance using quality oil? The biggest owner error posted over and over on these forums is owners trying to save money by using #46 hydraulic fluid because the Chinglish owner pamphlet says to. DON'T. That's why the exhaust stinks, the fluid turns black in an hour, and the little compressor needs replacement parts. Motor oil is as bad for compressors as hydraulic fluid. Unless you buy NON-detergent synthetic oil, motor oil leaves burnt residue in check valves and prematurely wears out the plastic resin piston rings. I've rebuilt compressors for guys who were getting black goo out of their bleeder valve and pressure wouldn't build as fast as the temperature rose.

Use a premium high pressure compressor oil. What you spend on oil will be saved on fewer repairs. There are many choices of high pressure compressor oils I use Chemlube CF500 from Filtertechs.com. I've owned 4 oil filled compressors over 14 years with no failures. This oil costs me $15 a quart and is changed annually. One quart of oil provides two oil changes on my dive compressor but 3 on a Yong Heng. Isn't your Yong Heng worth protecting annually for 1/3 the cost of a tin of pellets? It makes no sense to me to pay $15 for 100 FX slugs yet balk at the cost of 3 oil changes for the same $15 expenditure. 

The alternative is to save a few dollars, breathe in the stench of burnt hydraulic fluid and keep the vendors on Aliexpress happy with repair parts sales. After all, the manual says so. Would you clean your PCP with Hoppe's #9 if you knew it degraded the o-rings? Of course not. Why shorten the life of your compressor using motor oil or hydraulic fluid to save five bucks a year? An ounce of prevention is worth a pound of cure.

“Chinglish” you XXXXXX. Sorry my first post is dedicated to you. 

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This appears to be an oil that has it's main advantage in starting/operating well during extreme cold weather. but in the day time, it never gets below freezing around here; much more importantly to me is if the oil is transparent (not black or purple), so I can tell when it gets dirty by looking through the sight-glass. I looked everywhere for this info but found no reference to Powermate's opacity or color, so unless I find out, I am not going to order it for my compressor. In the So Cal desert we have the opposite weather problems with our compressors overheating. In the 15 minutes it takes to fill my dryer-canister and gun reservoir, my Yong-Heng gets up to 62-67 degrees C and over 80 degrees C, if I try to top off a medium bottle to 4,200 psi. I don't do that anymore unless it's wintertime when we can get a cold night in the 40s and use ice in the coolant bucket with an auxiliary fan on the compressor.

So if anyone knows if that Powermate synthetic is transparent, please let us know, and I will gladly switch over from that purple stuff that looks dirty from the get go.