Date: Wed, 20 Jul 2011 13:57:40 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Watching Oil Temp (long, as usual)
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re
Is there enough oil to be sure everything is oiled adequately at that
level?"
and such.
A wet sump engine is a compromise somewhat.
there are two main forms of oiling going on..
oil under pressure to the bearings - crankshaft , cam, intermediate shaft if
there is one, etc.
and splash.
The cylinder walls say ..
those get lubed by spash or by oil coming out of the rod bearings ..
basically, there is oil flying everywhere.
naturally ..
if oil level is low ..bearings may still get pressure ..
but everything oiled ( and cooled somewhat ) by oil will get less.
Better built engines have little oil nozsles that squirt oil under pressure
onto the undersides of the pistons.
All vw turbo diesel engines have that.
all 1.9 diesels, NA or turbo, have them.
Many later high performance inlne gas four VW engines have them.
then there is the matter of crankcase pressure.
Basically ...it would be nice not to have any ..
in the old days oil fumes and crankcase pressue was just dumped overbaord ..
the 'road draft tube' ...a vertical tube sitcking straight down , usually
off the side of the block - the bottom of the tube is cut off an an
angle..so the air flowing by provides a slight vacuum there.
My first car, a 56 Chevy inline six had that.
I moved to california in the late 60's ..and had to retro fit PVC ..postiive
crankcase ventilation ..
the first smog device of any kind. With that system, crankcase blowby is
sucked into the intake manfiodl and burned..
and all engines have that system now.
I mention that because ..if you overfill oil..
you get too much crankcase pressure, which can be a very bad thing.
If you want to ruin an engine ..just overfill it badly.
I had a rabbit diesel customer, who put 4 extra qts in his engine.
It was locked up solid.
removing the injectors and cranking the engine shot oil 30 feet.
Once running, it smoked like hell..
whether from an exhaust system full of oil, or damaged rings I never did
find out. It was a real mess though.
so regarding crankcase ventilation and blow-by ...oil level can't be too
high.
there is also the affect of oil in the sump and the crankshaft..
if the crankshaft can whip the oil into a froth ...that's extremely bad
news.
oils are fomuated though, with anti-foaming/frothing properties.
It's sure been studied and researched a lot ....lots and lots and lots...for
racing, for engine longevity etc.
I do believe 'between the marks' is excellent advice,
and that's what I do.
it goes on and on ..there are subaru-vanagon guys with late model engines
that smoke white smoke out the tail pipe under load and lugging.
They are going nutty on their crankcase breathing systems.
In racing cars..
they work very hard to get rid of crankcase pressure ..
and a 'catch can' or tank ....to collect oil fumes that turn into oil
droplets, is common.
and we won't even talk about Dry Sump oil systems..
that's a whole other world.
You can study about engine oil, and engine oil systems 'forever.'
There's a lot to it.
but the logical simple answer is 'oil level between the marks.'
and you won't get in trouble sticking to that, I do believe.
also ..'old wives tales' about oil and engines ..
like run it a qt low ..
or put ...whatever in it ....cod liver oil ..I never pay attention to any of
those.
I mean really ..
manfufacturers spend MILLIONS ( and the military, etc. etc. etc. ) studying
this.
How likely is it that Farmer Joe is going to discover that a bit of yogurt
in the oil is a new magic cure.
Not likely at all, is what.
I do believe in some addtives sometimes. I like Prolong transmission
additive ..can tell the difference in shifting.
On engine oil..
just use decent quality stuff, drive it nice, keep 'er in perfect tune,
change oil ( and other critical fluids ) in an appropiate manner, and
you'll do just fine. And keep it between the marks usually.
scott
www.turbovans.com
----- Original Message -----
From: "Dave Mcneely" <mcneely4@COX.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, July 20, 2011 1:01 PM
Subject: Re: Watching Oil Temp (long, as usual)
> ---- Rocket J Squirrel <camping.elliott@GMAIL.COM> wrote:
>> On Wed, 2011-07-20 at 13:28 -0400, David Beierl wrote:
>>
>>
>> > Dennis Haynes has determined experimentally that a major cause of
>> > high oil temp in the WBX engine is frothing, which has led to his
>> > recommendation to fill only halfway to the mark.
>>
>>
>> Interesting. I know about frothing, didn't know it was likely if the oil
>> were between the marks. So Ian might have been onto something when he
>> said to run the oil at the bottom mark and see what happens.
>
> I think the recommendation as referenced above by David is "halfway
> between the marks." I do believe the indication to add oil at the lower
> mark generally still holds, except for Ian's one outlier vote. But I
> could be wrong. Is there enough oil to be sure everything is oiled
> adequately at that level? Just askin', since I really don't know. When I
> was young, I knew an older fellow who said, regarding any vehicle he was
> using at the time, "I run 'er a quart low." I did not know why, now
> maybe I do, but then again, maybe I don't.
>
> mcneely
>>
>> -- RJS
>
> --
> David McNeely
