why is my compression bad? :(

[txrocco@sbcglobal.net (ATS - Patrick Bureau)]

Now this is very similar to what I have done before on GM and Ford engines,
and though I looked for the info in the Bentley found no break-oin
recommendations and found nothing, I did find 2 suggested ways....

VW Owners manual states:

p49 1985 vw scirocco owner's manual

The internal friction in a new engine is high. it will diminish gradually as
all moving parts adjust to each other. you can contribute to extending the
service life and economy of your engine by observing the following
pre-caustions;

during the first 600 Miles/1000 kms;
Full throttle should be avoided.
the maximum permissible engine speed is 4200 RPM
from 600Mile to 900 miles the speed can be gradually increased.
and they show a chart about before and after 600 miles point with speed
relative that should not be used on what gears....bla blabla...


According to :1975-1992 Vw A1 Haynes Manual

Initial startup and breaking in after overhaul

Once the engine has been installed in vehicule, with spark plug out of
engine, and the ignition system disabled, crank the engine until oil
pressure register on the guage or indicator light goes out, install spark
plug, wires and restore ignition functions.start engine and let warm up to
noraml operations, then shut engine off and check levels.

Drive the vehicule to an area with minimum traffic, accelerate at full
throttle from 30 to 50 MPH, then allow the vehicule to slow to 30mph with
the throttle closed, repeat procedure 10-12 times. This will load the piston
rings and cause them to seat properly against the cylinder walls, check
again for oil and coolant levels.

(so far all above is usually done at the factory)

Drive the vehicule gently for the first 500 miles (no sustained high speed)
keep the oil and coolant level in check, not unusual for an engine to use
oil/coolant during break-in period.

Change oil and oil filter at approximatively 500-600 miles, for the next few
hundred miles, drive the vehicule normally dont pamper it oit abuse it.

After 2000 miles change oil and filter and consider engine is broken in.


ATS - Patrick Bureau - txrocco@sbcglobal.net


=>-----Original Message-----
=>From: scirocco-l-admin@scirocco.org
=>[mailto:scirocco-l-admin@scirocco.org]On Behalf Of Rabbit16v
=>Sent: Monday, March 03, 2003 12:23 AM
=>To: Scirocco List
=>Subject: Re: why is my compression bad? :(
=>
=>
=>I'd like to here why too, Daun.  I haven't ever really been EASY on any
=>break-in but I have never been told to run a motor HARD to break it in.
=>Just doesn't sound right??!!
=>
=>Dave
=>
=>> From what I've read on breaking in engines, there seems to be two ways:
=>run it hard for awhile, or run it relatively easy for a longer amount of
=>time.  I broke the engine in on a road trip, for the first 400
=>miles I would
=>get up to about 65mph, drop down to 40, then mash the gas back up
=>to 70mph.
=>It has been revved above 5k, but only maybe once every 3 weeks or
=>so!  What
=>exactly do you mean by screwed?  If I did break it in wrong, what are the
=>results of that?  Thanks-
=>> Rob
=>>  Daun Yeagley <vwdaun@yahoo.com> wrote:Robbie,
=>>
=>> The wear limit on the JH is 109 psi.
=>>
=>> Now as for babying the engine, that's the worst thing you
=>> can do, especially when breaking in an engine. In order to
=>> break in the engine you need to run it h-a-r-d. If it's
=>> been 10k though, you may be screwed. Won't hurt to try
=>> however. Just be sure the oil is up to 80 C or so
=>> beforehand, but then wind it out to redline often, and do
=>> the same on downshifting, i.e. time it so you'll be in the
=>> 5-6k range.
=>>
=>> Daun
=>>
=>>
=>> --- Robbie Cotner wrote:
=>> >
=>> > I ran a compression check on my JH 8v today, 135-140psi
=>> > on all cylinders. Adding some 80w-90 to the cylinders
=>> > raised all readings ~10-12psi. This thing was rebuilt
=>> > 10k ago, immediately after the rebuild I had 150psi on
=>> > all cylinders!? I was hoping compression would increase
=>> > once the rings got seated. From what I've read 130psi is
=>> > the minimum for JH's, I'm not happy. Is this why my
=>> > engine has such low power? I really have babied this
=>> > thing, never revved above 5k, I've changed the oil many
=>> > times and am running synthetic 10w-30. My exhaust smokes
=>> > all the time, but the smoke is white as a ghost and I
=>> > attributed it to the cold... my spark plugs also show no
=>> > indication of burning oil. Any opinions on this? Thanks
=>> > in advance,
=>> >
=>> > Rob
=>> >
=>> >
=>> >
=>> > ---------------------------------
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