Black Yong Heng oil

[Dog]

Assuming combustion by dieseling in our second stage piston as the source, my 2 cents would be some are getting a bit higher compression? Soot from where, the 1st stage or that nasty old piston rod? Seems like everyone would have blackened oil?

Looking around you will see some have found the blackened remains of their 2nd stage piston and in very severe cases, top piston driven into bottom piston due to heat, detonation, lack of oil...soot?

My crankcase was inspected before first put in service looking for any machining debris from factory so dash those thoughts...

 

[Stubbers]

Assuming combustion by dieseling in our second stage piston as the source, my 2 cents would be some are getting a bit higher compression? Soot from where, the 1st stage or that nasty old piston rod? Seems like everyone would have blackened oil?

Looking around you will see some have found the blackened remains of their 2nd stage piston and in very severe cases, top piston driven into bottom piston due to heat, detonation, lack of oil...soot?

Lol. I said it was more likely from oxidizing oil than combustion yet you failed to mention that? I mentioned soot as a common cause of blackening oil..

 

[Dog]

Pulled top cylinder head and tank. All was super clean with no visible black gunk on top of 2nd stage piston. I think I’m going to reverse here and reassemble then clean all check valves. I’ll reorder the seals used and wait for another 10 hours or so. I’ll see about ways to further lower tank temp to avoid the blackened oil if possible.

Distilled water and light mix of antifreeze used for first 2.5 years, switched to Red Line distilled water for the last 2 years. The Seco Lube seems to be holding dieseling down in the 2nd stage for last 2 years.

 

[Dog]

Aliexpress, found complete o-ring kit and complete piston with rings,crank and second stage with seals $13 shipped. If ever deliver, LOL. Will save for whenever next rebuild. Cheers

 

[Airgun-hobbyist]

The oil turning black is aluminum/cast iron wear, and is from a lack of oil because the oil level is too low to adequately splash oil inside of the crank case. Folks need to raise the oil levels so it is at or just above the top of sight glass window.

I've been experimenting with these compressors for a while now, having gone through a few of them for various reasons. I found that the oil turns a black color not from excessive heat or dieseling, but from aluminum and cast iron wear. The black oil is from metal particles suspended in the oil. (That is why the oil separates and becomes somewhat clear again when it sits for an extended time; the heavier metals drop to the bottom as 'sludge' when it sits). The oil level needs to be raised so it is at or just above the top of sight glass window (not just to the red center dot on the glass but we'll above it.)

The oil is "picked up" by a thin cone-shaped needle -like protrusion at the bottom of the connecting rod and flung around the crank case. This needle is barely contacting the oil when everything is at rest and oil is at the middle sight glass fill.

Low oil means the motor is starving for oil in more ways than just splashing lube around. Adequate oil dampens the harmonic vibrations within the motor also. These harmonic vibrations have broken thousands of reciprocating motor in the past 120 years. Add more while it is running and you will hear the thing become more quiet from the needed lube.

 

[cosmic]

I guess rubber particles from the front cover gasket...

 

[Dog]

The oil turning black is aluminum/cast iron wear, and is from a lack of oil because the oil level is too low to adequately splash oil inside of the crank case. Folks need to raise the oil levels so it is at or just above the top of sight glass window.

I've been experimenting with these compressors for a while now, having gone through a few of them for various reasons. I found that the oil turns a black color not from excessive heat or dieseling, but from aluminum and cast iron wear. The black oil is from metal particles suspended in the oil. (That is why the oil separates and becomes somewhat clear again when it sits for an extended time; the heavier metals drop to the bottom as 'sludge' when it sits). The oil level needs to be raised so it is at or just above the top of sight glass window (not just to the red center dot on the glass but we'll above it.)

The oil is "picked up" by a thin cone-shaped needle -like protrusion at the bottom of the connecting rod and flung around the crank case. This needle is barely contacting the oil when everything is at rest and oil is at the middle sight glass fill.

Low oil means the motor is starving for oil in more ways than just splashing lube around. Adequate oil dampens the harmonic vibrations within the motor also. These harmonic vibrations have broken thousands of reciprocating motor in the past 120 years. Add more while it is running and you will hear the thing become more quiet from the needed lube.

So everyone is starving from oil? Or the ones not having issues overfill their crankcase? My unit sits low in the back due to the rubber feet so with oil at middle of red dot, it is deeper near the dipper.

This has been brought up before so would like to hear from others on their oil levels. Curious to your oil used and if using stock pump?

Saw a wiz bang U-tube video last night. Guy had about 6 computer radiators and a flow modified head. He ran the pump for an 1:15 to fill a big bottle with temps at 70C? No additional cooling on the motor!

 

[Airgun-hobbyist]

So everyone is starving from oil? Or the ones not having issues overfill their crankcase? My unit sits low in the back due to the rubber feet so with oil at middle of red dot, it is deeper near the dipper.

This has been brought up before so would like to hear from others on their oil levels. Curious to your oil used and if using stock pump?

Saw a wiz bang U-tube video last night. Guy had about 6 computer radiators and a flow modified head. He ran the pump for an 1:15 to fill a big bottle with temps at 70C? No additional cooling on the motor!

I am using Ingersoll Rand high compression oil or Air Venturi compressor oil. I witnessed the oil blackening and a crank journal seizure after the dipper broke off (then using a middle sight glass fill). After freeing it and cleaning up the case I measured everything multiple times and ran the motor with different oil levels to come up with the determination that a low oil level has zero benefits to this small simple motor.

People are not "overfilling" their crankcase if it is not becoming an issue with breaking things, oil consumption, or oil being forced into.places it is not supposed to go. Further, good splash oiling is also keeps pistons cooler.

From what I have seen, based on the OEM water pump and 5 gallons of antifreeze/water mix, and 10-15 minutes of run time, if the oil is getting hot enough to burn or the rings are worn to the point where there is high compression blow-by, then the compressor is in need of a rebuild and is struggling to build compression.

 

[Healthservices]

So out of curiosity, how does the second stage piston get lubrication?

Allen

 

[Dog]

I am using Ingersoll Rand high compression oil or Air Venturi compressor oil. I witnessed the oil blackening and a crank journal seizure after the dipper broke off (then using a middle sight glass fill). After freeing it and cleaning up the case I measured everything multiple times and ran the motor with different oil levels to come up with the determination that a low oil level has zero benefits to this small simple motor.

People are not "overfilling" their crankcase if it is not becoming an issue with breaking things, oil consumption, or oil being forced into.places it is not supposed to go. Further, good splash oiling is also keeps pistons cooler.

From what I have seen, based on the OEM water pump and 5 gallons of antifreeze/water mix, and 10-15 minutes of run time, if the oil is getting hot enough to burn or the rings are worn to the point where there is high compression blow-by, then the compressor is in need of a rebuild and is struggling to build compression.

Thanks for the reply!

I guess too many people read the manual that claims overfilling will cause "air valves will easy carbonize, if oil too low will result in piston sticking" with warning stickers over front of crank case. LOL, I guess we can all agree AW46 not the right oil.

One poster said that the Bauer pumps were turning Seco 500 black and we have one that says he has no issues but tries to keep the temperature low.

My pump pressure is fine, From the posted pictures do you see anything nasty about the valves? The uppermost reed valves are light tan with no build up.

What water temps do you try to keep? I'm making notes from the posts but will continue to use last half quart of the Seco lube but will try to reduce the water temp/runtime to see what difference this makes on my pump.

Before your dipper broke, did you ever have blackened oil at any time before failure? Lots of post using different oil but leave out this fill level.

Thanks again.

 

[Dog]

So out of curiosity, how does the second stage piston get lubrication?

Allen

Looking at the drawings,oil mist thru bottom piston rings gets filtered thru the moisture / oil separator, front left. The bottom half of the 2nd stage could see some oil mist through the rings, no? I'm thinking the 2nd stage pressure seals center and self lube and wipe the 2nd stage bore to keep any dieseling to a minimum. I saw no evidence of black carbon on the output side of my second stage, top reed valves very light tan to bare looking.

Anyone?

 

[Dog]

Fanatic about keeping YH cool, rarely over 50 degrees C, just filling guns. Used HUSKY Full Synthetic Compressor Oil (Flash Point 460F) first two years without issue, no odors but did find evidence of combustion on high-pressure piston. Switched to SecoLube 500 (Flash Point 520F) ($37@ quart) enough for next two annual oil changes, as well. WM

Worried..your oil level is kept on red dot or top of sight glass? Still using stock pump or upgraded? Your just using iced water right? TIA

 

[WorriedMan]

Worried..your oil level is kept on red dot or top of sight glass? Still using stock pump or upgraded? Your just using iced water right? TIA

Oil @ top of red dot as indicated on front cover label. Foolishly broke OEM water pump by pulling on wire to remove from water bucket, replaced with same volume (600L/H) aquarium pump on eBay for $11. If water bucket lower than compressor would have gone for higher volume pump. (New pump has stronger wire connection.) Use frozen plastic lemon juice bottles, keep nine in freezer. Standard Operating Procedure is install pump/hoses, fill bucket, add ice bottles, wait 20 minutes, start water pump to chill room temperature compressor to 18 degrees C range. Start external fan, begin filling gun, fan and water pump stay on until filling session ends and everything cool to touch. Switch ice bottles out, as needed. WM

 

[Dog]

Thank WM.
Just checked the manual again. It lists .5 liter...17oz! I found 10oz about right if we believe in the leveled Red dot.

I will test tomorrow. I pulled and cleaned the 1st stage X-over fittings, the cheap steel fittings with the double Doughty washers. Threads full of corrosion in 4.5 year build up. They need $$ fittings with single thick (copper?) washer for less chance of leak.

 

[Dog]

I guess rubber particles from the front cover gasket...

Gasket appears fine, nothing rubs off. corners fragile looking but no leaks yet...