[Vwdiesel] Ring Break-In and Oil Consumption

[Gavrik Peterson]

Thanks, for all the responses to my question about the oil consumption
problem.  I am getting a clearer picture of why my engine did not
break-in properly.

Although my thinking about this is evolving, I suspect there were two
things which resulted in this bungled break-in.  One was that I did
not drive the vehicle hard enough, early enough.  Another is that I
used an oil that was too good at reducing friction.  I may never know
for sure which was operative.

Don't really know, but I am thinking that the Kendall Super-D 3 (SAE
30) oil I used may have been a poor choice for break-in.  A friend of
mine, tells me of a friend who tried to break-in a rebuilt spark
ignition engine using a Kendall oil.  He found that after a few
thousand miles the consumption rate had not decreased much, which is
similar to my problem.  He recovered by draining the Kendall and
running a inexpensive oil for a few hundred miles.

So, figure that I need to run some kind of minimal additive 'straight
grade oil' and see if that works.  Right now I am investigating what I
should use.  The alternative is to follow Val's suggestion and use a
low viscosity straight grade aviation oil.  I see that Shell makes an
aviation oil that contains no wear of friction additives and is sold
for aircraft engine break-in.

I Called Kendall and talked with one of their technical people about
their 'non-detergent' oil.  I wanted to know what additives it
contained.  The woman said that they have changed it so that it will
meet the newer API specifications and that it now contains detergents
(not a problem for me) and a small amount of anti-wear additives (not
so good).

I am continuing my search for a candidate motor oil.  Does anyone have
a suggestion?

  --  Gavrik


On Mon, 28 Feb 2005 14:02:41 -0500 (EST), you wrote:

>OK, I'll chime in.  I've rebuilt as many diesels as gasser engines.  With 
>one exception the diesels were all VWs.  I'd have to sit down and look 
>at my maintenance records, but I'll guess between 11 and 13 VW diesel 
>re-ring jobs, either with glaze-breaking, or a re-bore.
>
>First, the surface should be rough, as most stones will leave it.
>I'm sure Gavrik did it, but the bore should be THROUGHLY cleaned
>prior to assembly.  I use a nylon brush, and water soluible cutting
>fluid, with some detergent (as a wetting agent).  Dawn works fine.
>Simple green does also.  After cleaning, a coating of motor oil applied 
>with a rag or paper towel is just fine.  
>
>Ring sizeing is important, as in cleaning and checking the dimension 
>of the ring lands.  I'll file rings so that they are on the smaller
>end of tolerance...each and every one.  I figure that way I can get the 
>max amount of wear out of the rings.  The rings get motor oil on them 
>when they get compressed.  No grease, so Slick 50, no STP.  
>
>Regarding oil, over the last 30 years I've had access to tribologists
>who are nationally recognized in their field.  Countless hours have 
>been spent discussing (and getting taught) about lubrication and 
>the phenomena which occur with lubrication.  Their advice 30 years
>ago, and today remains that normal engine break-ins should be 
>performed with mineral oil.  Detergent is not needed.  Multi-vis
>is not desirable, EXCEPT where environmental conditions demand it.
>Artic or sub-artic breakings might qualify.  
>
>Multi vis oil has a large volume of VI, and that percentage goes up
>with the spread.  Years ago (30) , I took a can of 10W50 STP oil, which I 
>though was great stuff, with a wide vis spread.  They analyzed it and
>showed me just how little of the can was oil,  Like 64% or some such 
>number.  Performance testing the oil in a test jig showed how
>the service characteristics of the oil were measureably different
>from even cheap straight weight oil, under the right circumstances.
>
>Avoidance of detergency is not a big issue, but the thought is that with 
>straight oils, there are less film strength improvers.  The VW diesel
>does not require EP lubes due to high contact forces, and a NA
>diesel is well within the range of mineral oil temps.  The VW diesel 
>is not a very high speed engine, nor is it a high temp engine, as far as 
>engines go, so there really isn't the need for anything other than 
>a straight weight mineral oil, with minimal additives.
>
>During breakin, oil should be added in 1/2 qt increments, and the sump
>be kept at it's upper limit.  
>
>In this instance, I would revert back to a light straight weight oil, 
>which would probably be a SAE 30.  (The truth is, if it were my own
>engine, I would use a SAE 20, which ould work just fine in the temps
>we have here (below 40F).  Run the car hard, without sustained full
>power operation, and varying power requirements on the engine.  Do 
>not run high RPMs without load on the engine.
>
>Dispersant oil is OK.  Detergent oil is not apporved in aviation engines,
>and offers no real advantage in break-in.  The oil should NOT have 
>anti-scuffing additives, or any EP additives.  
>
>The most important aspect of break-in is the seating of rings to the 
>cylinder bore.  Failure of that process results in the requirement to 
>de-glaze (disassembly) or use other despirate measures (Bon-AMI).
>
>In Garvik's situation, he may have glazed cylinders, and light weight oil
>without film strength improvers, extreme-pressure and anti-scuffing 
>additives is indicated.
>
>Run the vehicle hard, without extended full-power and varying the RPM.
>Put time on it.  If you can't get the oil consumption lower, you can 
>escalate to disassembly or other measures.  
>
>If you have porous chrome plated bores, rules are different.  If you have 
>high pressure cams and lobes, the rules are different.  If you're running
>nickel composite (Nickel+Carbide) then the rules are different.
>
>Sorry about the repitition (numerous interrupts).  I'd run the light weight 
>oil, and cut open the filter after 500 or 1000 miles, and see if you have 
>some new debris.
>
>
>Val
>
>
>
>
>> Gavrik Peterson  relax  NOTHING drastic is going to happen.
>> 
>> I am not and Never was a mechanic  ---- BUT the number of coffee breaks =
>> and beers after work
>> with THE MECHANICS ?  ----did something rub off ? .
>> 
>> I found that the flyboys got the ringseating ---pinned right down.
>> 
>> Loren mentioned long time ago that to get a gasser shop to fit a VW =
>> diesel piston
>> with small gap was difficult  ----to get a flyboy mechanic to fit it is =
>> impossible.
>> 
>> Aircooled  Aircraft  fitting would be considered limit of wear for a VW =
>> diesel mechanic in Germany.
>> 
>> I just had an old friend die  ----  who designed a diesel  many years =
>> ago  so let me get over the
>> grief and I shall explain what I found out about ringseating.      He =
>> was a nabor and became
>> a good friend   early 1960  es. 1962 ? .
>> 
>> Summary ?    make the crosshatch DEAP   ring gap SMALL  and pistons =
>> TIGHT in bores.
>> 
>> And stagger ring gaps.    ---I am a flyboy type and lots of the ringjobs =
>> I did was aircooled
>> AC engines. -----so I have a problem getting those pistons tight .   BUT =
>> remember they are
>> spcial pistons. ----not gasser pistons. ---------   wait to we get =
>> chromed cylinders then the fun starts.
>> 
>> I have seen Gavriks engine and it is a beauty  ----all painted and =
>> CLEAN.   And it sounds good
>> with NO SMOKE here.  Pump a tad too advanced.    If you Gavrik drove =
>> that Rabbit from day
>> one like you did here  ??? ----fuddy duddy driving is NOT the problem.
>> Let me tell you all he drives a lot more agressive than I do.
>> 
>> More on this  ------when I recover.
>> 
>> Hagar.
>> 
>> PS :      May 1945   I got my sticky little finger on my first REAL =
>> diesel    Jumo 205   I
>> think it was.------    is that not 60 years ?  --- right now that plane =
>> and engines are in
>> a museum ---in Denmark. 3 engine flying boat. "Anders And"    Donald =
>> Duck..(in english).
>> _______________________________________________
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>> Vwdiesel at vwfans.com
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>> 
>
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