Date: Tue, 13 Sep 2005 10:16:22 -0500
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: interesting lifter thinking?? 1.9L still a problem child
(update)
In-Reply-To: <001c01c5b86f$8e617740$6401a8c0@noner4688xfd1h>
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Stan,
Every new engine that I had experience with ALWAYS had metal in the
filter and/or screen and on any magnets. No matter how well measured,
machined and fitted, the moving parts are not perfect and the parts are
going to "wear in" to each other by rubbing off material. A closer fit
is actually acheived this way. As you well know one will actually have
better compression on an engine after the wearing in period (break in)
than before the engine is ever started.
The best example of this that I have ever seen was on an aircraft
engine that had chrome plated cylinder barrels and grey iron rings
installed. Pre-run compression was so-so, and then the engine was run on
a test stand. The engine didn't acheive temperature and the rings
glazed. What a mess. Low compression, high oil consumption. Oil drained,
engine flushed and reoiled, rings were replaced, cylinders honed to
remove any glaze, engine run at high loads with reduced cooling air,
and the cylinder temps went way up - not overheat but at the top of the
green on the gages, in about 20 minutes the temps began to drop, and
then steadied about mid-temp/mid green. The engine break-in period was
run to completion and a compression test done. Compression was right on
for a new engine. Oil was drained through a paint strainer then flushed
with solvent, and in the bottom of the screen was all kind of metal.
Very fine filings, mostly ferrous, because the magnet would pick them
up. The engine was oiled again, run again, and drained again. This time
the oil was kept to be put back in the engine. There was no metal that
second time.
Modern filters will get metal most times. I like to cut my filters,
flush them, and see how much metal is accumulating with each oil change.
I also like to keep tabs on how much is ferrous, brass, and babbit. It's
a magnet and visual thing, but it gives me some idea of the status of
things. Over time there will be a gradual increase in the metals with
each oil change. One more means by which to keep track as to how things
are internally.
regards,
John Rodgers
88 GL Driver
Stan Wilder wrote:
>I find this dubious unless the engine is run without an oil filter. Also,
>the first step to a proper engine assembly procedure is to thoroughly hot
>scrub
>all the components which includes using tube brushes in the lifter bores.
>George
>---------------------------- Clip ---------------------------------
>I've run in many rebuilt VW engines on my test stand and in every case I had
>a tea spoon full of metal shavings and debris in the strainer plate after
>that first 20 minute run in at 2000 rpms.
>I don't think this relates to getting the lifters filled with crud but the
>material is certainly there.
>I've had occasion to disassemble an engine right after the run in process
>and you'd be surprised how much wear is put on the bearings during this
>time.
>Much of this wear is caused by abrasive particles small enough to escape the
>filter process.
>
>Stan Wilder
>Engine Ceramics
>214-352-4931
>www.engineceramics.com
>
>
>
>
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