Oil Temperature

[Frank DeBartolo]

Re: Oil Temperature

Hank,

Clear as mud!!! What about Avblend?? I use it on every oil change. Appx 18-20 bucks per can but I understand that it penetrates and protects the metals of the engine.

Frank D
N43684

[Hank Jarrett]

Re: Oil Temperature

Never used it, but I am suspicious of all the "penetrates the metal" claims. May be true, but I haven't ever read a real evaluation on one so I don't use them.
Hank
OK, I HAVE read reports on them, but they were from the companies marketing the additives.

[Frank DeBartolo]

Re: Oil Temperature

Hank,

Cant remember because it was appx 5 years ago and I should have printed out the report--don't know who published the report, but as I remember the story and how it goes, it seems that AOPA had a Cessna 310 with similar time on both engines. They used Avblend on one engine and no additives on the other and after a good amount of hours flown, they disassembled both engines and the one with Avblend was significantly better. I should have printed out the article and saved it but that is why I add appx a buck an hour to my flying. My IA and I did a major overhaul on my engine 300 hours ago tach time and I fly somewhere 70-100 hours per year and I have very good compression and very good oil consumption. I installed four Millenium Cylinders. That also could be a reason. I use auto fuel 75% auto and 25% 100 LL. Since you know a lot more than I do about all this stuff--all I do is fly the airplane and am looking for the least amount of problems, it seems to work for me, however, I am particular as to how I run the engine and it seems that I need to cover up 75% of that little hole in the front of the cowl.

Frank D
N43684

[NY86]

Re: Oil Temperature

There is a misconception that the oil has to be hot enough to boil the water out. It doesn't. It has to be hot enough to evaporate the water. I am pretty sure most of the water in the oil comes from condensation and not combustion (MOST) and a hot engine will evaporate the water out, just not as fast as one that the oil reaches 100C.

I disagree.

If you change the oil on an engine and let it sit all winter long, there will be no water in the oil come spring. If, on the other hand, you fly it every day for a week and the oil never gets above 150 degrees there will be a milky emusion of oil and water in the filler neck. One of the main byproducts of combustion is water. It flows with the blow-by into the crankcase where it gets entrained into the oil. My opinion, 150 is not hot enough to evaporate it off faster than it accumulates.

AFAIK, Avblend does nothing to help or hinder this process. My opinion is to save your money for the overhaul, but...

Also how does viscosity affect the oil temp?

Usually this is phrased the other way around. Higher temps lower the viscosity. At the point where viscosity starts to have an effect on temperature, you've likely got other problems too, like melting bearings...

[Hank Jarrett]

Re: Oil Temperature

Like I said before, I don't claim to be an expert on oils. For myself (and in my plane), I use what the Continental manual says with no additives. For fuel, I use alcohol free auto fuel with the STC (available from the FBO where I fly). There may be better ways out there but that is just how I do it. I figure I don't fly enough hours to make a fight with the FAA worth it. They seem to take exception to things like MMO when they catch us using it. Don't even know what is required to use Avblend. I WOULD like to read a good independent evaluation if anyone knows which AOPA issue had it (I have about 20 years worth in the attic).
I just assumed the "viscosity affect the oil temp" comment was said backwards (something I unfortunately do too- fairly often). His other comments indicated to me he knew enough that he wouldn't be fighting a problem from a self-destructing engine.
I'll stand beside my comment that oil doesn't need to exceed 212 just to evaporate the water. It WILL evaporate, but it will take longer. If you are blowing by more water than normal temperatures will evaporate, you need to check your rings. I'm going from memory here, but I thought nominal operating temp for a 65 Continental was 120 to 200 with a 220 red line. Water boils at 212 in a standard atmosphere. You shouldn't have to run that hot just to keep water out.
If I’m wrong, PLEASE show me! We are all here to share and learn. When it comes to oil, I’m just an amateur and am willing to listen to any expert.
Hank

[Frank DeBartolo]

Re: Oil Temperature

I used to think that 120F to 150F was OK and if I flew and the temps got to at least 140F that was all I needed, except someone who I know and trust said that if I fly, it should not be for less than one hour and that 180F is the minimum target. Less than that and the water will not boil out. Problem is that my airplane runs appx 100F above surface temps. IE 80F at surface gets to appx 180F on the oil temp gauge. If it is 50F out, then it's 150F on the gauge. That is one reason I don't fly below 30F. I sure would like to......

Frank A

[PT13Pilot]

Re: Oil Temperature

Frank,
I was "forced" to use Avblend at a shop I worked for, did some digging, and learned a few things it does and doesn't do. This is opinion only, but I don't believe it soaks into anything but your wallet. The stuff smells like ether with some light oil, water is thicker. That being said, one thing it does exceptionally well is remove carbon. Our little Continentals, and especially the bigger carbed O-470's are nice little carbon generators that also spin a prop fast enough for you to fly behind, especially with 100LL. Since you already have Milleniums on yours, I'd say forget the Avblend. (knock on wood) I haven't seen a Millenium stick a valve yet, which with Continental cylinders happens all the time. Just fixed a transient Funk last month for a stuck valve. See the well used rope for the all too common "rope & ream" for that problem. I will say, it did eliminate sticking valves on 3 IO-240's that the flight school had in abused Katana's. They had the same valve sticking problems like the other little Continentals. I jerked a couple jugs on one we sent in for overhaul after the avblend and lack of sticking valves. The stems I looked at were clean, so were the ring lans. And the only thing we changed was ad Avblend.
After doing some digging, and I've slept since then so this is from memory. The parent company that makes Avblend also makes Z-max, the crap sold at Wal-Mart and used to have an infomercial, you remember, the "drive it without oil for 100 miles" stuff. They had a lawsuit against them for the usual Slick 50, snake oil, claims they can't substantiate. So my guess is their FAA approval is based on the fact that it doesn't hurt anything. It does do a good job at carbon removal, that I can verify from experience. But for 20+ bucks a can, save your money. Use good oil, fly often, change often, and go on with your life.
Chris