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s_morrison57 s_morrison57 is online now
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Join Date: Jan 2009
Location: Vancouver B.C. Canada
Posts: 2,082
Ronnie
No offence taken, and 0w40 might be a better choice but this article says different on the other points you mention. Again this article was about oil, in water cooled engines and they only gave cS #'s @ 3 temps., 75*, 212* and 302*F but the oil will act the same at the given temp. regardless of the engine cooling, and they didn't cover every different viscosity but 10w30, 0w30, up to 10w40 all have the same cS #'s @212* and all of the oils are too thick at start up and are all to thin at 302*. They did compare 20w50 oil and it was 250cS at 75* (too thick), 20cS @ 212* (too thick) and 5cS at 302* (too thin), the other oils were at 3cS @ 302*, only oil that's made for these temps (racing oil) will give you the proper 10cS @ 302*F.
I don't know about aircraft engines but they do use specially formulated oils and those engines are rebuilt every 2000 hours or less, there is a limit to cold starts for these engines??, in choppers for sure.
I'm going to try and post a link to this article.
I kinda thought I knew a little bit about oil, turns out most of what I thought was wrong, I think the guy who wrote the article is an oil engineer.
I did find out about ZDDP, in its hayday it was used as a VII, viscosity index improver, all VII's break down over time and use, it was a cheap VII so it was used in higher PPM counts in the old days. Its main advantage was as an antioxidant or corrosion inhibiter and its been almost eliminated from modern oils because of emissions and the damage it does to catalytic converters. Synthetic oil doesn't have VII so it doesn't break down like the dino oils do and as synthetic wears and loses some of its properties it still will maintain its original viscosity, unlike dino oils. I can't remember the PPM count on the ZDDP in the Swepco oil but it's really high compared to other formulas and may be way more than needed, I'm not sure on that but I did read that 0.03% was more than enough for the corrosion inhibition but how that correlates to PPM I don't know.
Finn
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Old 05-26-2013, 09:39 AM
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