Date:         Mon, 8 Dec 1997 11:24:21 -0400
Reply-To:     mark keller <kelphoto@BRIGHT.NET>
Sender:       Vanagon mailing list <Vanagon@Gerry.SDSC.EDU>
From:         mark keller <kelphoto@BRIGHT.NET>
Subject:      Re: Cooling System failure Prevention Idea
Content-Type: text/plain; charset="us-ascii"

I originally thought that an anode system that had a "filter" or some
method of keeping chelated particles from the sacrificial process of
entering the coolant stream, would be a helpful thing.

However, after looking at the way the corrosion occurs, see Tim Smith's
post re: HEADS, the sacrificial annode would not be "connected" to coolant
which is trapped beneath the flexiable head seals and is doing the actual
damage on the waterbox motor.

I suspect that some type of "sacrifical annode" or other chemicial which
get's exahauseted in the process is already a componet of commercially
prepared coolant that is "aluminum" friendly. I just felt that maybe VW's
formula may have a additive that was specific to the wasserbox problem.

Having seen manufacturing plants that make several varieties of the same
product, I'm aware that each product is manuactured under different
specifications by the label owner. So unless either a BASF engineer assured
me that the formulation of EVERYTHING they make is identical to VW or it
turns out that corrosion,is the secondary effect and that preventing the
coolant from getting under the seals is the REAL solution then I'm gonna go
with the $14 dollar times two gallons, as a $6 dollar a gallon "hedge"
every two years.  I guess I've thrown $12 bucks away in other ways.

 I do symathize with the notion of not giving VW anymore money that absolutlaty
possible. I guess it's kinda a payback for their poor support in parts
pricing, dealership repairs, and just general lack of corporate
professionalism. However, I don't want to pay a bigger price for my
vengence, so I try to use some restraint, at getting even at all costs.

BTW VW if your listening, the tendancy of customers and employees to rather
see a company fail, by any method they can wield, as a way of retribution
for poor treatment is well documented in corporate culture.  The kick' em
while their down mentality may seem counterproductive, but it happens. Pay
attention, your numbers suggest something at headquarters isn't working!


>What we need to come up with is some sort of sacrifical anode like the
>system Mercury Marine uses to keep the aluminum from being eroded due to
>galvanic action.  Without something along these lines, I dont think anyone
>is going to win this battle with this poorly designed engine.  My van has
>over 200,000 miles on the orginal engine and I'm on my third set of
>headgaskets.  They simply do not hold up longer than +.- 70,000 miles.
>
>
>
>If I get some time I will do some research on the anode deal.
>
>Regards,
>Justin Jensen
>SLC Utah
>-----Original Message-----
>From: mark keller <kelphoto@BRIGHT.NET>
>To: Vanagon@GERRY.SDSC.EDU <Vanagon@GERRY.SDSC.EDU>
>Date: Saturday, December 06, 1997 4:54 AM
>Subject: Cooling System failure Prevention Idea.
>
>
>>I just finished the flushing of my cooling system, then using Autobahn,and
>>distilled water to replenish it with. I guess that's a every two year job.
>>Some knowledgable people on this list have said that no one cure exisits
>>with regard to the corresion problem. Sevearal senarios have been posted as
>>to the coolant leak problems. I discussed the problem of corresion beneath
>>the head gasket with VW guy, who said he'd seen it on even engines that
>>weren't leaking, it was always present. Seeing the head gasket is basically
>>flexiable seal, I feel that perhaps a sealing problem is really the root
>>cause rather than a corrsion problem alone.
>>
>>I've thought a lot about this cooling system corresion problem and am ready
>>to say my piece. I'd suggest perhaps a short question-aire type response in
>>the future to really verify this theory.  But in leiu of it I want to share
>>some ideas. I've tried to take every thought as far or extreme as I can to
>>explore the possibilities of this problem. So some effects may not be as
>>severe as I'm suggesting.  I'm trying to get to a point of being able to
>>say that thus a so a condition is to be avoided and here's how to do it. .
>>I realize up front that this is theroy, but I feel it explains varity of
>>situations I've read about here, and the design compromises of the bus and
>>its engine, and specifically the design of the head gasket.
>>
>>My feeling is that the problem has a few componets, but the basic theory is
>>that coolant can be forced beneath the head gasket seals in certain
>>situations. I feel the temparture of the motor is a component but don't
>>know where the tempature is "line". Basically I saying at the very least
>>when the motor is first started and then run at higher than say 1500 RPMs
>>before the engine is warm and therefore expanded fully. High water pressure
>>coupled with low clamping force of the steel head studs is the major cause
>>for water invading the head gasket sealing area.
>>
>>  I define the clamping force to be the pressure that the head nuts exert
>>on the heads which "clamps the cylinder head to the cylinders."  This
>>clamping force is dependand on the lenght of the steel studs in the block
>>to the bottom of the nut staying exactly the same relationship to the
>>distance or lenght from the cylinder head boss, which the head nut and
>>washer rides on, to the point at which the studs are threaded into the
>>engine casings.
>>
>> In other words the with two different types of metal, steel and aluminum
>>alloy,opposing each other to clamp the gasket together, if their respective
>>rates of expansion and contraciton are not identical, which they are not,
>>then the force that is generated by these two materials will vary with
>>there tempature.  Ordinarily this rate difference proses no problems within
>>a certain tempature range, and ordinarily this reduction in clamping force
>>would necessarily mean that a head gasket seal would have insuffcient force
>>applied to it.  However there many head gasket failures, and quite a few
>>possible components that excerbate the dissimilar metals expansion and
>>contraction.
>>
>>Additionally the Subaru engine design of the 6 cyl I looked at had the
>>engine case and cylinders cast together, and thus could use a shorter
>>studs, thus cutting down the total amount of contration and expansion that
>>the head gasket had to compensate for.
>>
>>  The other conditions I discuss cover the susceptability of the dissimiar
>>metals used to construct the motor to weaken the clamping force on the head
>>gasket, and uniquness of high revving engine, coupled to a requiment for
>>the water pump to push water over very long cooling circuit.
>>
>>
>>COLD ENGINE
>>
>>I'll try to discuss this in an orderly fashion. The VW guy said that the
>>Head gasket water leak "recalled repair" was just to "retorqe the heads to
>>a higher torque setting.  Knowing that the engine head gasket relys on both
>>the expansion and contraction rates of all of the various metals to be
>>similar in its operating range. The metals being used are:engine case,
>>magnisium,and alumunin, steel head bolts, and aluminum cylinders. Once the
>>engine is at operational tempature expansion completes the total clamping
>>force, the engine design of being opposed with removable cyliniders
>>maginifies this because there is a greater distance between heads and block
>>attachment points for the studs, and thus a longer distance at which a
>>dissimlar contraction rate to make a difference.
>>
>>I feel a second componet HIGH water pressure. The vanagons water pump
>>impeller is designed to generate a lot coolant flow  and overcome the much
>>larger friction area of the  front radiator location and hoses to and from.
>>Also the water pump is required to provide adequate coolant flow water pump
>>operates over a very wide operating range engine rpm. It would be easy to
>>state categorically that Anyone starting up and driving a cold engine would
>>be over 3000 RPM with a minute of start up..  The thermostat spring is
>>supposed to relieve  pressure build up, but again on first start up cold
>>soaked engine in low ambient tempatures with the operator going to high
>>RPMs, I feel that this is a good bet that the water pressure inside a cold
>>engine is much higher than at normal operating conditions. To a smaller
>>degree but still a fact, the suction caused by the piston's intake stroke
>>coupled creates a greater still pressure differential between water and
>>head sides of the head gasket.
>>
>>A second theroy would be that the "errosion" of the head surface occurs
>>first, when water gets in between the head and the heat of cylinder forces
>>steam to pit the head surface repeatedly.  The corrosion then would just be
>>evident when the gasket  seal fails  completely, and coolant is present all
>>the time. I don't really buy the corresion theroy all the way, since
>>reports of "corresion" occur in well maintained vehicles.
>>
>>Another caveat is failure or restriction anywhere in the cooling system
>>that makes the water pressure abnormally high.
>>
>>Another problem, depending on the actual engine temps at which the clamping
>>force of the head bolts is reduce by dissimilar metal contration, is that
>>fact the the VW engine dissipates heat quickly, and cools down rather fast,
>>plus that the radiation is not in "warm" engine compartment like common
>>vehilce, and loses heat quicker too.  If the dissimilar metal contraction
>>occurs at a relatively high  tempature, then Stops and starts of say a half
>>an hour or so could be enough time for the engine to get cold enough for
>>the clamping force of the head gaskets to be below operational values.
>>
>>I guess this last theory has probably been a focused fix for sometime since
>>its a passive one.  Better resiliencey of the actual head gasket. My guess
>>is that the orginal ones failed because of shrinkage, or hardening.
>>
>>In conclusion, I suggest that a simple water pressure guage would be a
>>better way to gain information about when the engine is prone to water
>>intrusion under the head gaskets.  My basic suggestion it to let the engine
>>idle until the at least the temperature guage shows a movement before
>>driving at higher RPMs.  Depending on ambient tempatures and driving /time
>>stopped/ cycles, and the actual temperature where the clamping force is
>>reduced, allow for warm up before operation at high rpms.
>>
>>
>>
>>Sincerely Mark
>>91 Carat WE
>>"Lazarus"
>>

Respectfully,
Mark Keller
91" Carat WE
"Lazarus"