[Vwdiesel] Ring Break-In and Oil Consumption

[James Hansen]

Any diesel tractor engine that is rebuilt gets started, warmed up, valves
reset, then goes on the dyno and gets the piss run out of it as they vary
loads and rpm.  Seems to work every time, and there is no provision to
decel.  Gassers have a throttle butterfly, that gets different vacuum
loading happening when off the throttle and going down hill, and the rings
get a chance to cool and wash the grindings off the cylinder walls as you
prepare for another burst.   Diesels being non-throttled, I can't see this
as being much of a factor, as they are basically just coasting against
minimal compression pressures, but still enough to keep the rings more
seated than a gasser... as opposed to operating under loaded full throttle
compression values, which forces the rings against the cylinder walls
harder- which is what is effecting breakin.

On the engine in question, I would use regular dino juice, and drive the
hell out of it, doing long top gear acceleration runs starting at a low
engine speed, (not lugging) then keep it floored up to speeding (35-4000
rpm), then go off the throttle to slow down and repeat.  This is what should
have happened the first time.   You could try replacing the oil with cheap
gasser oil, then change it out after a half hour or so of playing.  I doubt
it has as much to do with the oil type, as the driving technique.  Every
time I have broken in a motor, you get it warm while driving, check stuff
over, then do the long acceleration runs... first one is a cloud behind,
next one is less, then less, then less... by the tenth time, the rings are
seated and the smoking stops.  It happens that quick if all is right.
Friction modifiers like zinc additives are used in high performance engines
to care for the camshaft and solid lifters on high lift cams during break
in, and the rings break in fine... but you still go out and drive the piss
out of it as above. Oil consumption in the long term isn't quite as much of
an issue however. ;-)
-james


-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com]On
Behalf Of LBaird119 at aol.com
Sent: Tuesday, March 01, 2005 10:00 PM
To: vwdiesel at vwfans.com
Subject: Re: [Vwdiesel] Ring Break-In and Oil Consumption




> How about downshifting during that decel to keep load on engine up and
rpms
> up?
>


  I just strive for keeping it within normal driving rpm or a tad higher.
Downshifting tends to slow you down so might as well just stay in
high gear and romp it back up and decel more again.
  I discovered this while riding my worn out YZ 125.  It needed rings
and bore.  When it had been ridden a while it'd lose a lot of power.
Only two things tended to help.  Let it completely cool down or
decel down a hill or two.  Just one of those fluke things, discovering
that but it really tended to prove true.  Made me wonder if the old
break in procedure of floor it, decel, floor it decel wasn't as much or
more for the decel than the accel.  At least on a gasser.  Diesels
seem to need that heavy load to break in properly.
    Loren
_______________________________________________
Vwdiesel mailing list
Vwdiesel at vwfans.com
http://www.audifans.com/mailman/listinfo/vwdiesel
--
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 266.5.1 - Release Date: 2/27/2005

--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 266.5.7 - Release Date: 3/1/2005