Compressor oil

[Mad Scientist]

Hi all,

I am new here please forgive me if I placed this in the wrong area.

I have an issue and I am wondering if someone could help me with it. I reciently built an air compressor and was using CRC's professional line of SAE 30 weight oil for the v-twin single stage pump and everything seemed fine during the break in period, After which I switched to the Royal Purple Synfilm recip. 100 and I immeadiatly noticed a very large jump in head and cylinder tempreture. This dumfounded me and shut the machine down. The ambient air temp was about the same during the operation with both oils, and the same "no load" condition.

Can anyone shed any light on why I would see such a large temp jump after switching to this oil?

Thank you in advance

 

[kenfain]

Welcome to the GJ, we really like pictures when possible, sometimes it helps folks visualize what you're working on. Besides I'd kinda like to see what you've built there.

Have you tried switching back to the original oil? Just to repeat the test, to see if it's really the oil.

 

[hangfirew8]

Oil in the cylinders would spike pressure. That could be caused by overfilling or migration past the pistons.

-HF

 

[Mad Scientist]

Thank you for your replies

I would like to post some pic's, my digital cam is way past it's prime so the quality may not be so good...lol

I will be switching back to the oil I used for break in on monday as it isn't available locally, I had to order more in.

I thought about the oil migrating past the rings, However I am not seeing any oil being discharged in the output air...Also I did abserve something interesting....

with the break-in oil I noticed a fair amount of oil vapor discharge from the crankcase vent and when I switched to the Royal Purple I observed less than a quarter of the oil vapor I was seeing escaping from the vent. So I figure that with the Royal Purple there is allot less oil being vaporized from the "blow-by" in the cylinders, So I am wondering if it is possible with this oil there is more of a sealing effect during compression and thus less air being forced past the rings allowing the pump to compress more of it's air resulting in a higher running tempreture?

I also noticed that this higher running tempreture is more localized at the cylinder head than the cylinder walls so it leads my to believe that it is more from the compression than metal to metal contact on the cylinder walls..

I will also time the tank fill with both oils to see if the tank fills a bit faster with the Royal Purple vs. the conventional CRC oil. I know it wouldn't be much but should lend some credability as to what might be going on.

I also have to do more research as I have found out that Royal Purple isn't compatable with some reciprocating compressor pumps.

 

[kenfain]

First, I'd have to think the amount of oil coming out of the crankcase vent as vapor, doesn't sound right. I'd think the amount would be so small, to not even be noticed. As an example, most people who've gone years without changing the oil, haven't said anything about having to add any oil. That wouldn't be possible if oil vapor were coming out in any significant amount. I know mine doesn't.

Second, give us an idea what the heat issue is because these things run hot. That's not a bad thing, unless you're cycling the pump all day, every day. Just like a car, there will be problems if it doesn't get to operating temp, and stay there for awhile. And that means hot. So are we talking normal hot, or excessive hot? ... If it were me I'd want to find out about the oil vapor first. But we'll likely need more back story, on why you noticed the heat. I mean, did it get red hot? Were there waves of heat?

Does the unit work as it should otherwise? ... I think it's a good idea to time the fill, with each oil. Record the fill time, with the oil thats in it. Then do the same for the new oil. You could always use a 30wt. non detergent oil from the auto parts, to do the test. Let us know what you find out about the fill time. Have pump, motor, and tank specs available, and someone can give the cfm output. Hopefully a compressor expert can sort this thing out pretty easily. There are several here at the journal.

 

[zkling]

What pump do you have?
What does the manufacture recommend?
I'd stick with a straight 30wt ND oil.

 

[Mad Scientist]

Ok, well Being that the pump is brand new and has no real hours on it to get a base line tempeture on I am really not sure. I am only going on the no load and the first few tank fills after break-in. However, the temps I have noticed between the first few fills and what I am noticing now with the use of the new oil are very different. The heads are not getting "red hot" But hot enough to really notice as compared to the unit running with the CRC oil in it.

Yes, The pump seems to operate fine as far as I can tell. This oil is CRC's SL22131.


Ok, here is the equiptment;

I am using HFT's 13 horse preditor gas engine

The pump is also from HFT Item # 60754

I am using a 7.75" motor pulley as I wanted to run the pump about 100 RPM lower than it's max of 1050. The pump pulley is 14.5"

The pumps rating is 15.2 CFM @ 90 PSI.

The manufacturer recommends a SAE 30 non- detergent compressor oil. I wanted to use the Royal Purple to facilatate easier starting and running in the brutal winters we have here.

Also, being that i will be using this machine in an unheated area during the winter months I don't think a conventional compressor oil will work as the temps range from 32 to -10 degrees F which is why I looked into the Royal Purple in the first place, those temps would turn any SAE 30 oil into a popsicle in the crankcase. I was looking at the Dewalt D55001 synthetic oil and I am wondering if anyone had any experence with type of oil?

 

[C96]

The oil vapor discharge you noticed was during the break-in period. You must give the rings a chance to wear-in. It is probably a coincidence that you noticed the blow-by change right when you switched to the Royal Purple. My guess is the break-in period allowed the rings to seat properly and if you would have replaced with the same oil after the break-in period you would have experienced the same results.

It’s always best to use what the manufacture recommends, but the Royal Purple you chose should be just fine as well.

Compressor heads and discharge tubes run very hot to the touch, can even burn your skin.

I think your way over thinking this, being overly cautious and a bit paranoid. As long as you have followed the manufactures procedure for the break-in period, just run it and enjoy.

If you’re going to follow through with your test by all means please let us know the results. I too now am curious about this oil thing.

In my compressor, I stick with what the manufacture recommends an SAE 30 non- detergent oil of no specific brand.

 

[Mad Scientist]

"I think your way over thinking this, being overly cautious and a bit paranoid. As long as you have followed the manufactures procedure for the break-in period, just run it and enjoy"

This very well may be, and if so then I will just have to grin and bear it. But having built this machine on a shoe string budget, with very little recourse for dealing with a breakdown that could have been avoided I would rather measure three times and cut once and be safe than sorry.

This is why I came here to ask the "experts" that have more experence than I do.

I do think it is more likely what you have said that's happening rather than an oil related issue.

Thank you for your assisstance

 

[crewchief]

Always run 30wt non-detergent. Synthetic is no good due to ring gap on pistons.

 

[Mad Scientist]

Ok, now you have me wondering. Is it because of the synthetic oil's viscosity that it slips past the ring gaps? I am not sure what to go with in this case. I know if I use the conventional during the winter months being the oil is so thick it will wear the pump out in short order.

Is their anyone here that has used a synthetic oil in similar situations that has had good luck with it?

 

[chris142]

most compressors do not have an oil pump. it just dips into the oil so theres no reason not to run the 30wt.if its really cold,like below zero maybe run a 20 wt. nothing wrong with synthetic compressor oil and many recomend it.you dont want detergent oil. it will mix with water and form mush while nd wont.

 

[Mad Scientist]

most compressors do not have an oil pump. it just dips into the oil so theres no reason not to run the 30wt.if its really cold,like below zero maybe run a 20 wt. nothing wrong with synthetic compressor oil and many recomend it.you dont want detergent oil. it will mix with water and form mush while nd wont.

Yes, these have the splash oiling system with the metal finger dipping into the oil and throwing it around.

Thanks for explaining that. I think I will give the Royal Purple a shot and see how it holds up.

Thanks for all of your help

 

[A_Pmech]

Cylinder head temperatures are not closely coupled to cylinder lubrication. If the cylinder wall temperature didn't change, then you don't have a lubrication issue.