Compressor oil which is the correct one?

Everyone has there reasons but Amsoil has been
on top of any review on oils for years. There flash point is over 500 F and being a dieaster based
oil stock I can not cast a blind eye to that. So to each there own.

Fly
According to the Amsoil website it's POA...
"AMSOIL PC Series Synthetic Compressor Oil is a long-life, premium
compressor lubricant based on novel, proprietary technology. It incor-
porates the highest quality, thermally stable PAO synthetics"
 
I have a Yong Heng, bought it used with very little use. The previous owner used Husky ISO 46 oil in it. The oil was clear when I purchased it. After filling 2 rifles from 150 bar each, the oil turned pretty dark. Unfortunately I am not able to find 527 or any of the better oils locally. Having it shipped is to costly. I was only able to find AMSOIL, the dealer carries both full synthetic and non synthetic. I bought the full synthetic. I removed the plate and sight glass and completely drained it that way. Initially I tried the plug, but it was barely coming out. I discovered when I took off the cover plate that there appeared to be rubbish or sealant material stuck in the drain hole. Cleaned it out and now can see plenty of day light. After filling with AMSOIL I filled 2 more guns from 150 bar to 250 and 300 bar. I noticed the odor wasn't as strong as before. At first glance when looking at the sight glass, I panicked, all the oil was gone??? Fortunately after looking at it closer it was at the mark. The oil was extremely cleaner compared to the Husky. I don't shoot much as I am limited to where I can shoot, but being able to fill my guns at my convenience is a blessing.
 
I have a Yong Heng, bought it used with very little use. The previous owner used Husky ISO 46 oil in it. The oil was clear when I purchased it. After filling 2 rifles from 150 bar each, the oil turned pretty dark. Unfortunately I am not able to find 527 or any of the better oils locally. Having it shipped is to costly. I was only able to find AMSOIL, the dealer carries both full synthetic and non synthetic. I bought the full synthetic. I removed the plate and sight glass and completely drained it that way. Initially I tried the plug, but it was barely coming out. I discovered when I took off the cover plate that there appeared to be rubbish or sealant material stuck in the drain hole. Cleaned it out and now can see plenty of day light. After filling with AMSOIL I filled 2 more guns from 150 bar to 250 and 300 bar. I noticed the odor wasn't as strong as before. At first glance when looking at the sight glass, I panicked, all the oil was gone??? Fortunately after looking at it closer it was at the mark. The oil was extremely cleaner compared to the Husky. I don't shoot much as I am limited to where I can shoot, but being able to fill my guns at my convenience is a blessing.
I hope you used non detergent compressor oil and not high detergent engine oil. The latter has dispersants to keep contaminates suspended in the oil so that a filter can remove them. When you have no oil pump and filter the contaminates accelerate wear because the oil is effectively turned into lapping compound.
 
I hope you used non detergent compressor oil and not high detergent engine oil. The latter has dispersants to keep contaminates suspended in the oil so that a filter can remove them. When you have no oil pump and filter the contaminates accelerate wear because the oil is effectively turned into lapping compound.
Yes.

Screenshot_20220717-125539_Chrome.jpg
 
I have a couple questions for the guys that have had detonation or dieseling when using RP oil. What temp. and pressure were you at when the incident occured? Did the incident cause a literal explosion? Pop a burst disk or? Or is this detonation or dieseling just an assumption made upon finding blackened char on the top of your piston upon dissassembly?
Curious
Chris
 
I have a couple questions for the guys that have had detonation or dieseling when using RP oil. What temp. and pressure were you at when the incident occured? Did the incident cause a literal explosion? Pop a burst disk or? Or is this detonation or dieseling just an assumption made upon finding blackened char on the top of your piston upon dissassembly?
Curious
Chris
You just hear a muted clap sound as it runs and it's done. The sound is not constant but just a few times. The pressure spike drives the second stage piston into the first stage so hard that the first stage piston caves in. The top or a portion of the brass second stage piston will be vaporized and soot will be left behind.
 
So did it happen at near max temp and pressure? Or for no apparent reason at all?
It happened under normal operating conditions. These compressors run a little cooler once broken in. Mine ran cooler than normal because I kept my stainless line wet by wrapping them in a wicking material and keeping water on them.
 
By know means my question comes across as not saying you are wrong, just a question. Could it have been
the screw holding the top piston rod onto the cast bottom piston could have loosened & let that brass piston
get lose & caused it to crash the upper end. Just wondering. RP has made top of the line synthetic oils for many
years. I was just wondering if something else could have cause it. I also wondered if those cheap cast pistons
they use with all that pressure being consecrated by that small dia brass rod in one small spot on the top of
the bottom piston could be a weak point. Just a thought.

Fly
 
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By know means my question comes across as not saying you are wrong, just a question. Could it have been
the screw holding the top piston rod onto the cast bottom piston could have loosened & let that brass piston
get lose & caused it to crash the upper end. Just wondering. RP has made top of the line synthetic oils for many
years. I was just wondering if something else could have cause it. I also wondered if those cheap cast pistons
they use with all that pressure being consecrated by that small dia brass rod in one small spot on the top of
the bottom piston could be a weak point. Just a thought.

Fly
No worries my friend. I spoke with a person at the factory in china a couple years ago who told me the primary piston had been redesigned with a thicker top. The second stage piston was still tight when I disassembled the compressor and there's no doubt detonation caused the damage. If you drove any cars through the 60s and 70s you know exactly what dieseling sounds like, especially when the car had an automatic transmission and you could make the engine stop after you turned the ignition off. That cluck and muffled clap gets burned into your memory. The top of the brass piston was melted to one side and there was carbon around the piston top. The rod and bearing surface looked new.
 
Many of us have the smallish 4500psi compressors that have a crankcase and require oil. Some even have the higher quality Alkin, Bauer or Coltri units.

These compressors are not just plain Jane compressors but are usually referred to as "dive compressors" as they put out 4500psi or better.

Although I have in the past used ISO 46 or regular Husky brand synthetic or synthetic blend compressor oils, in my Yong Hengs, and have not had a problem others have. I kind of knew this could be a problem already but a post from another member really brought it home to me. I eventually repented of this evil I had been involved in and put the correct oil in my compressor.

Plainly, if you do the research, regular compressor oil is not the correct lubricant for the high output compressors, we are using, that often see pressures near 4500psi.

Regular compressor oil is good for regular compressors where the pressure output is in the 100 - 150psi range.

When I finally decided to stop being so stubborn about spending a little more money on oil I switched over to the Seco Lube 500 synthetic dive compressor oil. They make an 800 oil that is good for this application as well.

https://filtertechs.com/product-tag/seco-lube-500/

Mobile and Shell also make suitable lubes for the "Dive Compressors".

This just a reminder that your ISO46, Husky and Royal purple or non detergent motor oils are not the correct oils for the compressors we are using.

I am aware of a couple of compressors that were destroyed by detonation problems, some months back. Both were using the Royal Purple. Although I am not sure of the root cause of the detonation neither was using the correct oil.
Welcome to the Dark side.🙃
 
Great to know & glad you checked that out on the piston. I just got to thinking as I,m planing changing oil
when it’s time. Yes I do remember the 60,s I ran a injected small block Chevy front engine jr fuel dragster
from the late 60,s into the early 70,s out of Okla city. 😁 Yep those were the great days of drag racing, till
the little guy was $$$$ out.

Fly
 
Hello everyone! Nice to be here! I just took delivery of my Yong Heng this past Sunday and have filled it with the Air Venturi compressor oil sold by PA. Seems like it may be a good compromise for the super expensive blends. Any reviews on it?
Rather than worrying about the initial cost I like to think of it as 8 or 9 dollars per year for the high end oil. It's just not a significant cost in the world of PCPs.
 
I have used only Nuvair 751 oil in my YH since getting it a year or so ago. I looked at the SDS for 455 and 751 on the Nuair website and they look pretty similar. The 455 is "food grade" with a 275C flash point versus a 272C for the 751. Pour point is also lower for the 455 at -50 versus -25 for the 751 and Nuvair says 455 is thinner Both are synthetic high pressure compressor oil.