Date: Thu, 30 May 2013 11:10:19 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: oils and gasoline Oil Viscosity at temparature.
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Even 230 is nothing to get overly concerned about. With a few wrong moves I can readily get water boxer oil temp up to 270 or even higher. Then you will test that oil pressure buzzer regardless of which oil you use.
Dennis,
From my phone.
________________________________
From: Don Hanson<mailto:dhanson928@GMAIL.COM>
Sent: 5/30/2013 10:24 AM
To: vanagon@GERRY.VANAGON.COM<mailto:vanagon@GERRY.VANAGON.COM>
Subject: Re: oils and gasoline Oil Viscosity at temparature.
I concur on the oil temperature gauge being most informative. The
coolant gauge tells you about the coolant but the oil temp is a more
accurate 'read' on how hot your motor is running, how much 'heat-sink' it
has.
My inline VW Jetta motor usually runs at around 205f at highway speeds of
60-70mph. When I first swapped to the 2.0 liter block, I ran for a short
time without the VW oil/coolant heat exchanger adjacent to the oil filter
housing and I was seeing high-load temps of 230f (Autometer brand
gauge)...This caused me alarm so I plumbed in the usual VW heat exchanger
filter housing, to keep the engine internal (as indicated by my oil
temperature) temps lower. I keep a close watch on my oil temp and am
contemplating a second aux oil cooler with a thermostat, for those few
times I run the van fully loaded up long grades into headwinds, at speed.
My oil temp will climb after about 2 miles of 5% + grade,
On Wed, May 29, 2013 at 9:40 PM, Dennis Haynes <d23haynes57@hotmail.com>wrote:
> When reading SAE oil grades for multi-weight oils the lower or "w" number
> refers to the oil at 40C and upper number is at 100C. A common viscosity
> measurement is centistokes, (cSt). SAE 50 will have a viscosity near 18 cSt
> at 100C regardless of whether it is a synthetic or not. The Mobil 1 15w-50
> will have a viscosity of 125 cSt at 40C. A 20w-50 will be closer to 170 cSt
> at 40C. The synthetics usually have a wider viscosity index without as much
> need for modifiers and their performance can shine at temperatures far away
> from these standards.
>
> One thing that needs to be understood is that for loose tolerance engines
> or
> those that are worn too much clearance on one side always means less or
> insufficient clearance on the other side. As such loose engines can
> actually
> be more demanding of the oil to keep the parts separated.
>
> As important as an oil pressure gauge is it is even more helpful the have
> an
> oil temperature gauge. The Water boxer has a wonderful (?) ability to have
> oil temperatures not follow the coolant temperature, especially at high
> speeds and loads and the situation gets worse when the crankcase is over
> filled. It is these high oil temps that cause the loss of oil pressure both
> from viscosity loss and the case expansion letting the bearings get loose
> and the pump to lose its ability to pump. The oil can go into thermal run
> away and this is where we get those thrown rods. If not for this phenomenon
> the Water boxer would have no problem running with a *w-30 or *w-40 oil.
> For
> daily winter driving (to-from work) I use the 0w-40 which works just fine
> on
> my red van which is completely stock. For summer and/or long trips I want
> the 15w-50.
>
> Keep in mind that higher viscosity oils have their draw backs. They provide
> poorer lubrication when cold and they rob power and economy.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Stuart MacMillan
> Sent: Wednesday, May 29, 2013 12:26 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: oils and gasoline
>
> Ahh, these threads are so much fun! Everyone has an opinion and an
> opportunity to join in. I can't resist.
>
> Regarding better mileage with premium gas, if it doesn't contain 10% (it
> does here in WA, you are fortunate in Canada) you will get about 3% better
> fuel economy due to the lower energy content of ethanol (ethanol adds
> oxygen
> for more complete combustion). Since you are getting more than that, then
> you probably have some carbon build up that is increasing compression to
> the
> point where you get some knock with heavy loads on regular.
>
> Regarding synthetic oils and viscosity, the SAE rating is "effective
> viscosity," not physical viscosity. A 15w-50 synthetic oil is physically
> thinner than a 15w-50 dino oil, but the chemistry of a synthetic (more long
> chain molecules of consistent length plus viscosity extenders) offers the
> same effective viscosity lubrication with higher breakdown temps in a
> thinner (purer) oil.
>
> With its being thinner we can run into low oil pressure issues with some
> synthetics in our loose WBX engines (the hotter they get the looser).
> 15w-50 should be fine, but 20w-50 may be needed in worn engines since it is
> physically thicker than the 15w-50. Run the 5w oils ("mileage boosting"
> oil for modern cars) and you can have pressure problems at high temps.
>
> Which brings me to my last point. All WBX engines should have an oil
> pressure guage! Van Café has a great kit at a great price (I did my
> research):
> http://www.van-cafe.com/home/van/page_362_263/oil_pressure_gauge_kit.html
> Best money and two hours you'll spend.
>
> I had one on my '84 and am installing this one on my '85 this weekend (and
> I'll transfer it to the Subaru engine). It didn't keep me from blowing up
> my engine, but at least I knew I was on borrowed time:
> http://volksweb.relitech.com/21rodbrg.htm
>
> For more fun reading on oil look up "tribology," which is the science of
> lubrication. You will learn that two of the best known lubricants are
> whale
> oil and castor oil (Castrol's original formula).
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> James Eaton
> Sent: Wednesday, May 29, 2013 5:16 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: oils and gasoline
>
> >
> > Date: Mon, 27 May 2013 12:57:38 -0500
> > From: Jim Felder <jim.felder@GMAIL.COM>
> > Subject: Re: Engine Oil Question
> >
> > I don't think it's better, I think it's very good and moderately
> > priced. I know from many thousands of miles of experience that without
> > the right oil (of which Castol 20W50 is one) and the right filter, you
> > stand a good chance of hearing your waterboxer's oil buzzer go off on
> > a hot day of freeway driving.
> >
> > It has been explained to me by people who are in the business of
> > selling oil and in the business of building engines that the
> > waterboxer does not have tolerances that would take advantage of the
> synthetics' advantages.
> > It's like putting high test in the gas tank; it won't hurt the car
> > but it won't help it either, and costs more.
> >
> > Jim
> >
> Hmmm,
>
> Even back in the '80s, when I had my Rabbit, we were advised that if you
> wanted your engine to last you should run synthetic oil, especially if you
> ran a lot under adverse or high load conditions. And that was back when
> synthetics were all thin, thin, like 0W20. Now that synthetics are the
> same
> weight as regular oils, only with wider range (e.g. 15W50 is the same
> thickness as 20W50, except in the cold, where it's thinner for better lube
> at start-up), all engines, even those needing heavier oil to cope with high
> temperatures, can find a synthetic to do the job.
>
> And I have a contrary observation to your line about premium octane
> gasoline; our '91, with 290k km, gets 2-3 mpg more on 91 octane than on 87
> octane on the highway. (The owner's manual recommends the use of 91 octane
> under hot, high load conditions, which described our camping trips in
> eastern Ontario last summer.) A colleague who teaches and researches gas
> engine maintenance and repair suggested that the improvement is likely due
> to the superior flame front propagation properties of 91 octane under
> higher
> loads, and to the lower alcohol content (apparently in Ontario premium does
> not have to have the 5-10% alcohol that regular does).
>
> James
> Ottawa, ON
> '91 Westfalia Weekender
> =
>
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