[Vwdiesel] Decoking pistons

Wed Oct 6 15:37:59 PDT 2010

Bryan,

Emery grade
'60'

About 20000 miles/ two years, ago I hand skimmed the head, after a gasket failure. The sunk valves became closer to the pistons, and at true TDC, and exact cam set, there is no gap between the closing of the exhaust, and the opening of the inlet valve. 
I have improved it with 5 notch 1.5 gasket replacing the 2 hole 1.6 gasket, and advancing the cam by about 20 thou on the loose locking bar...  I've just remembered thart the exhaust shim gaps are at the lower end of their limit, and could give me a few more thou to play with...
I see I'm blocked yet again from the site. It must be because of that picture link :o(

Mark
  ----- Original Message ----- 
  From: Bryan Belman 
  To: mark shepherd 
  Sent: Wednesday, October 06, 2010 11:10 PM
  Subject: Re: [Vwdiesel] Decoking pistons

  Pretty cool, never heard of that honing trick.
  what was the emery sheet course # if you don't mind.
  So, that cleaned up the cylinder walls.
  you cleaned the pistons up, cleaned the groves out and put new rings on,same size?
  The valves looked good.  What do you think the contact was, just timing off for a bit before you corrected it?

  this is a 1.6TD Q.  yes?
  The same setup works well in a vanagon and I had the Exhaust Manifold, Intake and turbo and all but never did it and sold it all to someone else.

  Bryan Belman, Pt. Pleasant, NJ
  04 Jetta Wagon TDI PD, 100hp, 5sp -- running :<)
  92 Jetta 1.6 Eco-Turbo Diesel, 5sp -- running :<)
  82 Diesel Westy 1.9NA -- running :<)
  70 Type 1 stock Beetle -- Running :-) 

------------------------------------------------------------------------------
  From: mark shepherd <mark at shepher.fsnet.co.uk>
  To: vw fans <Vwdiesel at vwfans.com>; Bryan Belman <dieselwesty at yahoo.com>
  Sent: Wed, October 6, 2010 6:01:52 PM
  Subject: Re: [Vwdiesel] Decoking pistons

  I think these messages were just released by Loren after quarantine. :o)
  All shell bearings were good. No play in wrist pins either. Nothing bent, 
  all valves perfect. All I ended up doing in the end, was to re-ring [$22], 
  and a light honing with a plastic bottle covered with coarse emery paper.
  The subsequent results are on the mileage graph.
  The gumming up was probably down to my using multigrade oil. As it was using 
  it/burning it, I chose not to use quality oil, and used to top-up, rather 
  than replace. Still using multigrade, but will replace more often.

  Mark

  ----- Original Message ----- 
  From: "Bryan Belman" <dieselwesty at yahoo.com>
  To: "vw fans" <Vwdiesel at vwfans.com>
  Sent: Wednesday, October 06, 2010 10:35 PM
  Subject: Re: [Vwdiesel] Decoking pistons

  Looks re-buildable, but sure is ugly now. Wow, never saw rings like those, 
  have
  to see what things look like after they are given a good bath.
  Are you just going to hone the cylinders with the block in the car? you must
  have dropped the crank already.
  Bryan Belman, Pt. Pleasant, NJ
  04 Jetta Wagon TDI PD, 100hp, 5sp -- running :<)
  92 Jetta 1.6 Eco-Turbo Diesel, 5sp -- running :<)
  82 Diesel Westy 1.9NA -- running :<)
  70 Type 1 stock Beetle -- Running :-)

  ________________________________
  From: mark shepherd <mark at shepher.fsnet.co.uk>
  To: vw fans <Vwdiesel at vwfans.com>; mark shepherd <mark at shepher.fsnet.co.uk>
  Sent: Thu, September 23, 2010 9:58:03 PM
  Subject: Re: [Vwdiesel] Decoking pistons

  Sorry not meaning to bump this , but my linking skills are somwhat lacking,
  and most of the pictures weren't visible, [to me at least!]
  Click on the revealed picture!
  http://img255.imageshack.us/g/piston1andstuckrings.jpg/

  Mark

  ----- Original Message ----- 
  From: "mark shepherd" <mark at shepher.fsnet.co.uk>
  To: "mark shepherd" <mark at shepher.fsnet.co.uk>
  Sent: Friday, September 03, 2010 2:08 AM
  Subject: Re: [Vwdiesel] Decoking pistons

  >
  > At long last I got round to uploading some pictures. Here is a picture of
  > a set of rings. Not sure if they were of the 160psi cylinder, or one of
  > the two 200psi ones, or even the 270psi one. Has anyone run with bigger
  > gaps? The pressure was less than my old vw gasser. Scrolling should give
  > the other pictures, in no particular order, but titled according to what
  > they are.
  >
  > http://img809.imageshack.us/f/imgp9942.jpg/
  >
  > Subject: [Vwdiesel] Decoking pistons
  >
  >
  >>
  >> Greetings,
  >> Hopefully someone will be up on the other side of the world.
  >>
  >> Just taken my pistons out for a rering, I was having a 'little difficulty
  >> starting. Fuel economy averaging about 45 to 48 UK mpg. 3 pistons have
  >> single stuck rings,top or middle some of the gaps could be as big as
  >> 1/16th- 1/8th of an inch!!
  >> Bores good, and hastings rings fit to middle of VAG gap spec. Pistons
  >> are great and so are all bearings. It loks like my nocking for the last
  >> 20 to 30 ooo miles was exhaust valve clash. I always set belt accurately,
  >> but I overskimmed the head, and so this mayexplain that.
  >>
  >> However my question is this.
  >> Should I remove the thin layer of carbon deposit between top ring and
  >> piston face?
  >>
  >> Regards
  >> Mark
  >> _______________________________________________
  >> Vwdiesel mailing list
  >> Vwdiesel at vwfans.com
  >> http://www.audifans.com/mailman/listinfo/vwdiesel
  >>
  >
  >
  >

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