Date: Tue, 19 Feb 2008 22:54:19 -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: <000b01c8737f$13ff04e0$6a01a8c0@DADSTOSHIBA>
Content-Type: text/plain; charset="us-ascii"
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
>
>