[Vwdiesel] Any good machine shops in the Puget soundareaSeattle/Tacoma ...

[James Hansen]

that should read "measure parallel to the wristpin" ahead of the ring
grooves and behind it should be exactly the same dimension.
-J

-----Original Message-----
From: James Hansen [mailto:jhsg at sasktel.net]
Sent: Friday, February 17, 2006 10:06 PM
To: vwdiesel at vwfans.com
Subject: RE: [Vwdiesel] Any good machine shops in the Puget
soundareaSeattle/Tacoma ...


Due to differing thickness of material in each dimension, pistons are not
round when temperature change occurs, hence the difference in dimension when
cold vs hot.  Final grinding leaves the dimension across the wristpin
smaller than perpendicular to the wristpin because when hot, the thicker
material across the wristpin increses in dimension more than the areas where
there is no material. If you were to measure them when at 800F, they would
be mostly round, but then measuring methods suffer in accuracy as the
measuring tool heats up.
Measure perpendicular to the wristpin. behind the ring lands and ahead of
them.  It should be uniform across the same dimension.
The guy doing cylinder honing should know this however....
You want to see the words "Sunnen" on the cylinder hone, and it should look
fairly clean and well looked after.  Usually shops that own good equipment
do good work...  usually...
-james.

-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com]On
Behalf Of Cotter
Sent: Friday, February 17, 2006 11:01 AM
To: LBaird119 at aol.com; vwdiesel at vwfans.com
Subject: Re: [Vwdiesel] Any good machine shops in the Puget
soundareaSeattle/Tacoma ...


And do not forget that the pistons are "cam ground" which means they are not
a perfect circle-they are oval shaped--
I do not recall where to take the measurements. I believe the measurement is
taken perpendicular/parallel to the piston pin. ( say that one 5 times real
fast)
I had a VW trained mechanic in the stealership tell me an engine was junk;
until the service manager explained the cam ground piston to him--(warrantee
claim in 1983 as they fumbled around trying to find a noise which ended up
to be a broken flange on the front of the intermediate shaft.)

Good luck
Cotter



-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com] On
Behalf Of LBaird119 at aol.com
Sent: Friday, February 17, 2006 1:02 AM
To: vwdiesel at vwfans.com
Subject: Re: [Vwdiesel] Any good machine shops in the Puget sound
areaSeattle/Tacoma ...

  Whomever you have do the work, make sure they bore for the
proper piston to cylinder clearance.  Most shops want to leave
you with much more than the .001 specified clearance.  When
about .0025 clearance is wear limit, you don't want any more
to start than you need!
  I had to argue with the shop that did my last one or two.  They
wanted to bore it with almost .002 clearance and refused to do
.001 until I showed them in black and white!
     Loren
_______________________________________________
Vwdiesel mailing list
Vwdiesel at vwfans.com
http://www.audifans.com/mailman/listinfo/vwdiesel

_______________________________________________
Vwdiesel mailing list
Vwdiesel at vwfans.com
http://www.audifans.com/mailman/listinfo/vwdiesel
--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.15.9/261 - Release Date: 2/15/2006

--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.15.9/261 - Release Date: 2/15/2006

--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.15.9/261 - Release Date: 2/15/2006