Date: Wed, 15 Sep 2004 21:42:51 -0500
Reply-To: Al and Sue Brase <albeeee@MCHSI.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Al and Sue Brase <albeeee@MCHSI.COM>
Subject: Re: Disappearing Coolant - Head Leak?-Engine Oil Viscosity!
In-Reply-To: <000001c49b8a$3a21eaf0$6400a8c0@masterpc>
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Dennis:
Well put (as you always do!)
Empirical data would certainly show this to be true. Stan Wilder used to
talk about all the 2.1 Vanagons he'd see in Texas junkyards with rods
hanging out of the cases. I'd say nearly HALf the 2.1's I see on ebay
say they have bad oil pressure sensors, but it's only a $6 part. Right.
I probably made some horrible mistake putting my 87's engine together
back in 1998. (Ground the crank, used resized 1.9 rods, etc) but had oil
pressure problems within a few hours. Found a lot of aluminum swarf in
the oil filter for several changes (probably part of my oil pump). I
just grounded out the wire to the high pressure oil switch and put in
STRAIGHT WEIGHT 40 Shell oil. That was 50k miles ago. And not all easy
ones either. I once covered 87 miles in one hour in the mountains of
Pennsylvania. Some smartass in a Honda Oddessey, went blasting by me, I
thought I'd try to keep up. I can verify that the speedo needle WILL
touch 100 before the rev limiter cuts in at 5400. I'm SURE it was
downhill, it was dark and I couldn't tell, but it had to be.
I do give it an easy warm up when it's cool. When the starter will no
longer crank it (about 25F, if I remember, I change it for Mobil 1 15w-50).
But mostly this $1.25 Shell 40w works pretty good.
Good point about the archaic engineering. Anyone who'd seen a 1938 KDF
engine would recognize it instantly!
Al Brase
69 double cab, 87 Vanagon, others
Dennis Haynes wrote:
>5w-30 in a Vanagon is not appropriate or even safe for use in the Water
>boxer for extended high speed operation. It may work for a while, but
>eventually you will have oil pressure problems and you will eventually
>get to do that rod bearing replacement.
>
>Here are the major reasons:
>The oil pump is of an outdated, 2 gear design. As the engine warms, the
>housing expands increasing the clearance between the housing and the
>gears. This reduces the pumps efficiency (internal slip or leakage) and
>the pump can not maintain pressure as the oil viscosity also goes down
>with heat.
>
>In addition, as the engine warms up, the bearing to crank clearances
>also increase allowing more leakage which requires more flow from the
>pup to maintain adequate oil pressure. The aluminum engine case adds to
>this as you will also get leakage outside the bearings as the engine
>ages. This is why proper rebuilds need to have the case align-bored.
>
>The Vanagon engine operates at higher speeds for longer periods than
>most engines. Find another vehicle that needs 4,000 rpm to do 70 mph!
>Due to the shallow sump and parts turning/churning in the oil, oil temps
>can sky rocket and get out of control. It is not unusual for a stock 2.1
>to get the oil over 260F. The stock lube system will not maintain 10
>psi/1,000 rpms with 5w-30 under these conditions.
>
>Oil viscosity should be selected for the maximum that will allow the
>engine to start and get lubrication at the coldest temperature expected.
>With multi-weight oil the lower # represents the viscosity at 40C, the
>higher number at 100C. You also need to look at pour points to see how
>low a temp. Oil can be used. It is at the extremes where most synthetic
>oils shine. The Mobil 1 15w-50 is rated to flow at -35F. I find it is OK
>in the Vanagon to ~10F. There is now a 0w-40 designed for the European
>cars. Even the newer VWs have engine problems using the 5w-30s. I have
>been using this in my Fox and the wife's Audi with great success.
>
>Honda and Ford are now recommending 5w-20 for some of their engines.
>These engines are specifically built to use these oils in the hope of
>improved fuel economy. It may wrk there, but do not try it in the
>water-boxer.
>
> Dennis
>
>
>
>
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