Date: Thu, 14 Aug 2003 09:08:40 -0500
Reply-To: John Rodgers <j_rodgers@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <j_rodgers@CHARTER.NET>
Subject: Re: 2.3L WBX build, install, test drive,
and confounding questions... (pretty darn long)
In-Reply-To: <20030814045239.30277.qmail@web13101.mail.yahoo.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Damon, I can't address directly your problem, but wanted to relate this.
I used to work with air cooled aircraft engines. An aircraft engine on a
test stand right after a rebuild would always run hotter than normal,
then as things began to "Wear in", internal friction became reduced and
it would begin to run cooler. This break-in process was tracked by
plotting the temperature over time on a graph. During the run-in, all
the little microscopic high points of the new metal to metal contacts
would be worn off for a closer fit. Until that was accomplished, there
was a lot of friction and thus more heat. When all those little points
were worn off, and were no longer sticking through the oil film between
parts, the oil film could smooth out more evenly thus better separating
the parts, and the excess friction was gone and the temperature would
begin to drop.
After the test run and break-in, the oil was drained, the filters and
screens pulled, and all were washed out with gasoline and the whole mess
passed through a fine screen. There were always metal filings after
run-in. . These were always checked with a magnet to get a gross
determination as to how much iron bearing metal had worn off during
break-in. Old hands at the game of engine re-build could just look at it
and tell you if we needed to tear the engine down again or if the engine
was ok to ship. Newer, computerized instrumentation, along with oil
analysis, gives a better picture after the break-in run.
Your engine needs to be run with a straight weight run in oil. I broke
my current WBX engine in after rebuild on a straight 30 WT,
non-detergent oil. After a hard start because everything was so tight
with all new parts, I ran it at just above idle for an hour after first
startup, then changed the filter and drained the oil, and allowed the
engine to cool completely. Then I put on a new filter, added new oil,
then drove it for 100 miles doing 30 to 40 mph. Then changed the filter
and oil and allowed the engine to cool completely. Then drove for 500
miles at a fairly continuous 55 mph, then changed the oil and filter and
allowed the engine to cool completely. Did it again at 1500 miles and
switched over to 20W50 oil with a new filter. Didn't bother with the
engine cooling this time.
Each time I changed the oil, the amount of metal filings in the oil
diminished. Never had a lick of trouble since day one. Good compression,
good oil pressure. Oil and filters are cheap compared to the overall
price of the engine rebuild, and longevity sought, so i felt this
routine was fully justified.
I never had a low oil pressure problem, ever, on this engine. What you
describe, suggests that you will need to go back into the crankcase and
have the fits and clearances checked. One thing I did on mine during
overhaul, was to have installed a brand spanking new oil pump. Fits and
Clearances in the pump were to factory new specs. I feel that is a must
on every engine rebuild.
One thing you might also consider if you replace the oil pump, is
whether or not you can port and polish the oil pump inlets and outlets.
I believe Robert Lilley did this when he did his now famous "Lilley
Rebuild" in which he targeted engine performance increases throughout
the rebuild. Better oil flow was one item. Ceramic coatings for reducing
friction and corrosion control was another.
Good luck with this. We are all anxiously awaiting the final results of
your efforts. There are some of us who would like to follow your
footsteps on this rebuild, once it is completely successful and the bugs
worked out.
Regards,
John Rodgers
88 GL Driver
Damon Campbell wrote:
>I finished up the 2.3L WBX engine last week, and got
>it running this week (couldn't work on it over the
>weekend because of that whole "wedding" thing getting
>in the way - and i mean mine :-). So we fired it
>up... or at least tried to. Really difficult to crank
>over, but with a boost (4 year old battery...), it
>fires up, and we are all happy. A mellow drive to
>Santa Cruz over hwy 17 shows it running strong, and
>willing to get up hills with enough power in 4th gear
>- not crazy amounts, but enough to accelerate a bit,
>too, and not have to downshift (even at 40mph). It
>drives really well... smooth, quiet, and enough power
>to feel solid and not wholly underpowered.
>
>However. And this is a *big* however, there are two
>problems...
>1) When hot, even with a brand new battery, the
>engine simply won't crank over. At best, you may get
>1/2 a lazy revolution. It cranks over and fires up
>cold with some difficulty, but it does.
>2) Oil pressure is low (grrr...). When at full temp,
>idle is around 5psi and at say, 3000 rpm, we are
>closer to 20-25psi. These obviously aren't great.
>Not even close to good.
>
>The confusion is that these seem almost contradictory.
> No hot start almost seems like a bearing binding, but
>low oil pressure and smooth running seems like
>excessive clearances? Just stabbing in the dark here.
>
>
>I'm just about ready to pull it apart again and take
>it to volkscafe and have them rebuild the shortblock
>again, just so i know it is done right (quick plug for
>Peter's awesome customer service, btw). But i want to
>know if any of you have any thoughts on what these
>problems may be. In the stand, the crank turned over
>fine with no resistance, and with pistons installed,
>still felt pretty darn smooth... I'm pretty much at a
>loss, and could really use some help here.
>
>Thanks much to the list gods,
>-Damon
>
>(on a positive note, i have a really good idea of what
>is going on in the engine back there, and how to
>kludge up a 2.1/1.9 hybrid...)
>
>=====
>'84 Westy (Sparky)
>'65 Kharma Ghia (Dharma)
>
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