Date: Wed, 20 Feb 2008 14:25:42 -0800
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Electric Water Pump
In-Reply-To: <BAY125-DAV9D0C921779D2A554F2846A0230@phx.gbl>
Content-Type: text/plain; charset="us-ascii"
Hi,
Short stroke, large bore is definitely called 'oversquare'
And the opposite...................long stroke small bore is called
undersquare.'
I'm 100 % sure on this.
Fortunately I have not had to see the insides of an engine that had 100 %
a-frz in it.
The ones I see look like they had the same 50-50 mix in it for 10 years
straight - i.e. things looked awful !
I do lube sealed bearings. I use spray Prolong synthetic
grease............gets right past the seals and makes the bearing noticeably
smoother. It is amazing how fast alternators spin and how well they last.
But do tell me why a 94 subaru EJ22 water pump lasts kind of 'indefinitely'
and waterboxer ones don't.
My gf's 98 Outback has a 105K miles timing belt on it, and is now at
103,000 miles on the same and original w. pump, timing belt, and guide
rollers and tensioner. Same water pump all those miles, and that engine
will do 6,200 rpm, so imagine what the water pump is doing.
The w. pump is driven by the timing belt in that engine and the crank
sprocket and the w. pump wheels are about the same diameter, so the w. pump
is not turning much faster than the engine is, like it is on a waterboxer
vanagon engine, not that rpm itself is so directly related to how much
something that just spins wears.
So you've had better w. pump life on Dexcool ?
That's interesting and good to know.
I have it in my Mercedes.
Maybe I'll use that stuff more often.
Scott
-----Original Message-----
From: Dennis Haynes [mailto:d23haynes57@hotmail.com]
Sent: Wednesday, February 20, 2008 6:56 AM
To: 'Scott Daniel - Shazam'; vanagon@GERRY.VANAGON.COM
Subject: RE: Electric Water Pump
I confuse easily but I think the short stroke, large bore design is
considered under square. Yes, the Vanagon being under square keeps piston
speeds low for a given RPM but it is working and working hard. How many
modern cars use most of the available horse power to achieve highway
speeds? Yes, properly taken care of the engine does not seem to mind but
if your foot is down, it is working.
While the engine may not mind, the accessories and their bearings are
getting a real work out. And since these bearings can not be re-lubed,
their life can be shortened. That poor alternator may be doing 10,000 rpm.
As for anti freeze having abrasives, why else would silica and silicates,
(beach sand) be an ingredient. Have you taken a part cooling systems where
someone thought straight anti-freeze was a good thing? It is amazing the
stuff that collects. How about the residue from Dex-cool? Like some type
of plastic scrubbers.
Yes corrosion and erosion are different things. Both can be a problem. So
can cylinder liner cavitations erosion. This is a particular problem on
Diesels. Just ask Ford power Stroke owners that have replaced engines.
If you really want to get crazy with antifreeze, jump into the Diesel
truck world. You can really go crazy here.
As for water pump life, many cars need pumps long before 100,000 miles.
Usually it is a seal failure but smaller pumps now also go through
bearings.
I have owned FUN BUS since new. The first pump went at 49,000 miles. Seal
leak. Was replaced under warranty. Next pump was replaced while traveling
to Alaska, 96,000 miles. Developed a loud squeal. I replaced that one in a
campground in Michigan. Both times VW blue coolant was used. At 135,000
miles I flushed the system and changed over to Dex-Cool. That pump went to
almost 210,000 miles.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Scott Daniel - Shazam
Sent: Wednesday, February 20, 2008 1:54 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Electric Water Pump
A waterboxer engine is a pretty oversquare engine.......meaning short
stroke, large bore, and 4,000 rpm is just a nice spin. It's not
'working'
to turn 4K rpm.
Anti-corrosion additives in anti-freeze are abrasive ?????
I think you should offer some documentation or something to back up that
claim.
Don't mean to be offensive, but did you just pull that out of the air ? or
did you read it somewhere ?
The engines I service must not have a problem since I use a small amount
of
water soluble oil in the water/a-frz mixture, and I just don't ever have
corrosion problems. Of course I needs changing on a regular basis. Every
two years is the long standing standard.
You're using the word 'corrosion' and 'erosion' interchangeably - they are
different things.
Corrosion gets to a lot of cooling system parts all right !
I've seen cast aluminum hose connection points on diesel vanagon water
pump
housings rotted completely through. Aluminum under hoses seems to really
corrode 'nicely.'
Waterboxer water pumps do seem to last only about 70K miles.
Why would that be I wonder ?
All kinds of other engines have water pumps spinning just as fast and they
last much longer.
Scott
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Haynes
Sent: Tuesday, February 19, 2008 9:12 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Electric Water Pump
Water definitely erodes piping systems and other parts it moves through.
Water jets can be used to cut steel and concrete. Cooling system erosion
is a common source of failures. What do you think really happens to heater
cores and often radiators? The erosion wears the tubes making them thin
enough to leak. Automotive coolants can make things worse as part of the
corrosion control package is abrasives. These abrasives are also what
wears out the seal set. On the Vanagon, things are made worse as the
engine is often working at some 4,000 rpm. The water pump is spinning
almost twice as fast. No wonder those bearings often say no more. Using
high mineral tap water also adds to the water wear problem.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Kenneth Lewis
Sent: Tuesday, February 19, 2008 10:15 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Electric Water Pump
Allan,
It's a mystery to me how a fluid could erode the metal impeller. I stay on
top of coolant changes so I don't think it was that. I have the distinct
impression that failure rates did drop significantly when I switched from
Italian to German made water pumps.
Ken Lewis
http://neksiwel.20m.com/
<snip> I have compared a new pump to an old
>> one. The wear on the impeller blades is very evident . So an
>> electric driven water pump might prove a healthy gain in FE (fuel
>> economy).
>
> A worn impeller is caused by corrosion and/or cavitation. Neglecting
> to change the coolant as specified is often a contributing factor, or
> it could be poor quality materials in the manufacturing process.
>
> Allan
> --
> 1991 Vanagon GL
>
>