Zinc in oil question.
Got to thinking the other day, not only do I have three older cars without roller cams, but I also have various other older engines that do other jobs around here. Do I have to worry about the oil in my air compressor? Is it really as big an issue with cars that have had zinc in the oil for most of their lives.
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Re: Zinc in oil question.
An ounce of prevention is worth a pound of cure. Get some zinc oil. -
Re: Zinc in oil question.
Don't worry about the oil in your air compressor. I assume that you are talking about the shop unit. Just buy a good brand of Air Compressor oil and don't worry about it. You do not need, nor do you want all the additives that motor oil has in it.Dick WhittingtonComment
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Re: Zinc in oil question.
Agree with Dickie...use zinc oil in your old cars that need it, but use a specialized, dedicated air compressor oil if your compressor requires oil. Buying one type of oil by the case for everything that uses oil is not a good plan.
Mobil makes a good compressor oil that's available from industrial supply stores, both local and online...it's called Rarus 427. And, No, I'm not making this up...check it out.Comment
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Re: Zinc in oil question.
Compressors don't need the rich additive package of an API C-category oil, but I don't see how it can do any harm as long as the viscosity range is okay for the ambient temperature that the compressor sees.
What is the viscosity range of compressor oil?
DukeComment
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Re: Zinc in oil question.
Duke, here is a link to the spec sheet. SAE viscosity grade is ISO VG 100 from the container. No doubt there are cheaper alternatives, but I didn't like the idea of buying a generic product from HD labeled "Compressor Oil".
Mobil made/makes superior lubricants, and once freely supplied all their lubricant specifications on the internet. Now that they're merged with the Big E, the free flow of info is a casualty...you have to go to offshore dealers websites find spec sheets.
Edit: Mmmm, spoke too soon with limited information...here is the Mobil lubricant website. Everything and more than you ever wanted to know about oil and grease.
Rarus 427 in particular:
Last edited by Chuck S.; December 10, 2010, 11:57 AM.Comment
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Re: Zinc in oil question.
Most hydraulic and industrial equipment oils use ISO visosity grades, and ISO 100 is equivalent to SAE 30.
Here's a handy conversion chart:
I have an old compressor that sees little use and I use the same 15W-40 C-category oil that I use in all my cars.
I'll report if it ever fails because I used the "wrong" oil.
DukeLast edited by Duke W.; December 10, 2010, 12:48 PM.Comment
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Re: Zinc in oil question.
About the air compressors.
I was told NOT to use a detergent oil in my compressor and I did. It started draining the milk shake combo and It never stopped doing that. I saw another guy with a smaller compressor add detergent oil to his compressor and he said he had to because it 's been using more and more oil.
These were METAL ring compressors. I think I have a page in an old Quincy manual that recomends 30W non detergent, but you have the best bet using compressor oil.
DOMComment
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Re: Zinc in oil question.
This past summer I bought a new compressor from HD. 3.2HP, 10.2 SCFM @ 90 PSI, cast iron pump. (The old Sears oil-less ventilated big time). The following is a quote from the owners manual.
"USE SAE 30 INDUSTRIAL GRADE AIR COMPRESSOR OIL OR FULL SYNTHETIC MOTOR OIL LIKE MOBIL 1 10W30. DO NOT USE REGULAR AUTOMOTIVE OIL ADDITIVES IN REGULAR MOTOR OIL CAN CAUSE VALVE DEPOSITS AND REDUCE PUMP LIFE. FOR MAXIMUM PUMP LIFE, DRAIN AND REPLACE OIL AFTER THE FIRST HOUR OF RUN TIME".
-Dan-Comment
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Re: Zinc in oil question.
Compressors are of a completely different design versus internal combustion engines and the oils are generally not compatible, follow directions, use compressor oil or give them a short life....they don't have combustion by products thus don't need and are generally not designed to handle the additives as DOM experience shows.Comment
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Re: Zinc in oil question.
my sears unit I bought in the early 80s says compressor oil or 20w motor oil, try and find 20w nowdays. I just bought compressor oil at harbor freightMichael
70 Mulsanne Blue LT-1
03 Electron Blue Z06Comment
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Re: Zinc in oil question.
This advise makes absolutely no sense at all. "Regular automotive oil" has the same additive package as Mobil 1. The only difference is the base stock.
I wonder who writes this stuff.
Typical home reciprocating compressors are like small IC engines, but they don't have combustion byproducts that can contaminate the oil with harmful substances like acids and sludge, and they don't get as hot as an engine, so base stock oxidation is not a major issue.
I agree that they don't need "detergent" type engine oil, but they can use some anti-wear additive, which usually aren't in non-detergent oils (but is in most hydraulic oils.)
Again, I don't see how the additives in engine oil could create problems.
DukeComment
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Re: Zinc in oil question.
My Model A Ford uses non detergent 30W oil. I bought a case of Brad Penn oil for it. Has a lot of zinc in it.
Brad Penn also has 30W detergent oil with lot of zinc.
My Honda generator instruction book specially states not to use any kind of oil in it except their oil. Bull crap.
#1. I don't agree with that and #2. I have been using a ton of different brands of oil in the generator since I bought it in 1997 and so far the generator is still running.
Don't be taken to the cleaners when some company insists you only use their oil.
Use what you have in the cupboard and forget about it.
How do you lose a case of oil?? Old JD lost a case of oil for about 6 months. Since my place is always loaded with guys coming around I falsely accused one of them (in my mind) of stealing the case of good zinc oil.
Found it just where I put it. Under the steps along with my missing crock pot. Hell to get old. JDComment
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Re: Zinc in oil question.
Duke,
I was where you are now when I put what I thought would be better in my 10 hp compressor. They do get very hot when running and as you know the more pressure they pump the hotter they get. I can't touch my industrial compressor and would say it gets close to 200.
Also they want a LESSOR oil in them to keep the rings seated all the time.
As you already know the aircraft engines use the LESSOR oil during break in (stupid) so the rings will seat giving the engine it's rated HP. This is all at the expence of the cam & followers but now that the rings are WORN in the engine produces its rated HP and the performance figures in the POH (pilot operating hand book) fit the airplane and it will do what the book says.
I use detergent oil during my break in so I can save the cam but at the cost of about 1or 2 % power. I get over 25% life out of my engines that way.
What did that have to do with air compressors? The compressor is always at a stage of break in because there is no combustion that gets behind the ring in its groove to push the ring against the cylinder wall.
You would know better about this but I think it's about 1600 lbs pressure during the explosion of fuel in a cylinder. That is missing in the air compressor.
DOMComment
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Re: Zinc in oil question.
An air compressor behaves like an engine during the compression stroke. Granted, there is no combustion pressure (which peaks, briefly, in the range of 800-1000 psi for a naturally aspirated road engine at the WOT torque peak at sea level) to push the ring against the wall, but that means that a compressor can probably use a soft cast iron ring since loading is much lower, which will allow it to seat against the cylinder wall.
I don't like to compare light aircraft engine data to automotive because light aircraft engine technology is still basically 1940s vintage. There are hundreds of thousands of old general avaition aircraft out there, and the cost of certifying new technology for them is not economical, so most are stuck in the past.
Aircraft engines designed in that era and still in production, today require "ashless" oil to avoid spark plug fouling. At least that was the thinking at the time they were certified. Most oil ash is from the additives, so that's why aircraft engine oils have no detergent, dispersant, anti-wear, anti-foaming, etc additives and are basically non-detergent.
Concerning oil for pre-war automotive engines, I see no reason not to use modern C-category oil. It would also be a good idea to add a full flow oil filter and even a PCV system.
The non-detergent oils of that era had no additives, base stocks had much less oxidation resistance than current base stocks, and crankcase ventilation was poor. All this combined to create heavy sludging in as little at 10-20K miles. A little dose of modern technology in a pre-war engine will go a long way toward making them as maintenance free and long lived as modern engines.
DukeComment
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