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Useability of 92mm cylinders and pistons

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  • Bob
    My engine was built around 1980. It is a 2180cc AeroVee, 82mm stroke, 92mm pistons. I am rebuilding it and using a new engine case, crankshaft, connecting
    Message 1 of 7 , Jun 2, 2005
      My engine was built around 1980. It is a 2180cc AeroVee, 82mm stroke,
      92mm pistons. I am rebuilding it and using a new engine case,
      crankshaft, connecting rods, etc. The old case was filled with Porsche
      parts. I have noticed that current stroker 92mm pistons have the wrist
      pins higher up in the piston than non-stroker pistons. I have no idea
      if mine are like this. How can I confirm that my current pistons and
      cylinders will or will not work? And what the shims would be? Thanks!
      Bob
      MN
    • Chad
      Check out this link. http://www.cbperformance.com/catalog.asp?ProductID=1340 It may help with determining what you will need for spacers. You ll need to know
      Message 2 of 7 , Jun 2, 2005
        Check out this link.
        http://www.cbperformance.com/catalog.asp?ProductID=1340
        It may help with determining what you will need for spacers. You'll
        need to know your rod length. Use the deck height number in the
        engine calculator found here:
        http://www.cbperformance.com/enginecalc.html to determine compression
        ratio.

        chad

        --- In AirVW@yahoogroups.com, "Bob" <bbells@f...> wrote:
        > My engine was built around 1980. It is a 2180cc AeroVee, 82mm stroke,
        > 92mm pistons. I am rebuilding it and using a new engine case,
        > crankshaft, connecting rods, etc. The old case was filled with Porsche
        > parts. I have noticed that current stroker 92mm pistons have the wrist
        > pins higher up in the piston than non-stroker pistons. I have no idea
        > if mine are like this. How can I confirm that my current pistons and
        > cylinders will or will not work? And what the shims would be? Thanks!
        > Bob
        > MN
      • flybynightkarmarepair
        ... It s pretty unlikely your pistons are NOT stroker pistons. Even in 1980, they made them with the wrist pins re-positioned. If non-stroker pistons were
        Message 3 of 7 , Jun 2, 2005
          --- In AirVW@yahoogroups.com, "Bob" <bbells@f...> wrote:
          > My engine was built around 1980. It is a 2180cc AeroVee, 82mm stroke,
          > 92mm pistons. I am rebuilding it and using a new engine case,
          > crankshaft, connecting rods, etc. The old case was filled with Porsche
          > parts. I have noticed that current stroker 92mm pistons have the wrist
          > pins higher up in the piston than non-stroker pistons. I have no idea
          > if mine are like this. How can I confirm that my current pistons and
          > cylinders will or will not work? And what the shims would be? Thanks!
          > Bob
          > MN

          It's pretty unlikely your pistons are NOT stroker pistons. Even in 1980, they made them
          with the wrist pins re-positioned. If non-stroker pistons were used, the spacers under the
          barrels would have been huge to keep the deck height and compression ratio within
          reason.

          But why reuse these P's and C's anyway? They are cheap, cheap, cheap. If the engine
          needs a new case, rods, crank, due to wear it needs new barrels.....
        • Bob
          You know what, there are just too many questions on this engine (and at least one prop strike). Lord knows what Monnette and the other 3 or 4 owners have done
          Message 4 of 7 , Jun 2, 2005
            You know what, there are just too many questions on this engine (and
            at least one prop strike). Lord knows what Monnette and the other 3
            or 4 owners have done to it. Not to mention that incompetent boob of
            an A & P that said he was rebuilding it. Let's not get into that
            right now, I'm still swearing. Plus, by the time I got done buying
            the parts I need it would only be a few hundred dollars less than a
            longblock 1915. Anyways, Chad is right. It would be saver, better and
            easier to start from scratch and just get a whole new engine. I think
            I will just call Bennett and get a 1915 longblock or something. I
            have been bouncing back and forth on that and I guess money was the
            determining factor, but it was what i really wanted to do from the
            beginning. Thanks guys.

            --- In AirVW@yahoogroups.com, "flybynightkarmarepair" <ryoung@l...>
            wrote:
            > --- In AirVW@yahoogroups.com, "Bob" <bbells@f...> wrote:
            > > My engine was built around 1980. It is a 2180cc AeroVee, 82mm
            stroke,
            > > 92mm pistons. I am rebuilding it and using a new engine case,
            > > crankshaft, connecting rods, etc. The old case was filled with
            Porsche
            > > parts. I have noticed that current stroker 92mm pistons have the
            wrist
            > > pins higher up in the piston than non-stroker pistons. I have no
            idea
            > > if mine are like this. How can I confirm that my current pistons
            and
            > > cylinders will or will not work? And what the shims would be?
            Thanks!
            > > Bob
            > > MN
            >
            > It's pretty unlikely your pistons are NOT stroker pistons. Even in
            1980, they made them
            > with the wrist pins re-positioned. If non-stroker pistons were
            used, the spacers under the
            > barrels would have been huge to keep the deck height and
            compression ratio within
            > reason.
            >
            > But why reuse these P's and C's anyway? They are cheap, cheap,
            cheap. If the engine
            > needs a new case, rods, crank, due to wear it needs new barrels.....
          • robertshoover
            ... And the deck-height of your case. Stock, universal replacement case, you re generally safe to assume the cylinder base deck-heights are STD and all four
            Message 5 of 7 , Jun 2, 2005
              --- In AirVW@yahoogroups.com, "Chad" <cjstenson@a...> wrote:
              > You'll
              > need to know your rod length.
              ---------------------------------------------------

              And the deck-height of your case.

              Stock, universal replacement case, you're generally safe to assume the
              cylinder base deck-heights are STD and all four are equal but with a
              used or after-market case you need to confirm not only the height but
              its uniformity for all four spigots.

              It's also wise to verify the sealing depth of the spigot bores in the
              heads. When they are opened up for larger jugs there's always some
              'skim cut' involved. And if they've been flycut to reduce the chamber
              cc, you need to know by how much. Otherwise, you run into a real
              mare's nest when you try setting up the valve train geometry.

              Fortunately, none of this is rocket science, although it does require
              a number of accurate measurements. Once you have the data,
              determining the thickness of any required spacers becomes mostly a
              paper exercise. Of course, unless you have your spacers ground to
              order you'll be forced to use whatever is available, meaning a number
              of iterations to arrive at the best compromise.

              With the steady decline in the number of registered air-cooled
              Volkswagens the quality of VW parts -- and the honesty of the folks
              selling them -- has become something of a nightmare in recent years.
              Nowadays the hardest part of building a good engine is finding good
              parts.

              The hazard here is that while assembling a VW engine is a trivial task
              it takes only a single anomaly to blow the novice right out of the
              water. I see almost daily examples of heads, cases, rods and cranks
              that can not be used or which require some corrective action.

              The folks selling such junk are only interested in their bottom line,
              which like the number of Volkswagens, has been declining steadily.
              They have no incentive to offer quality goods and are shielded from
              liability because non-stock parts are defined as 'racing' equipment
              and do come under existing consumer-protection legislation. This
              places the Quality Control burden on the shoulders of the person
              building the engine. And while there are tons of How-To cookbooks for
              throwing together a VW engine, it takes a fair amount of tools and a
              bit of experience to tell if the parts are up to spec.

              The shade-tree types - non-professional mechanics who cater to the
              Kiddie Trade - tend to ignore the parts problem since the constant
              churn of ownership ensures a steady influx of technologically naive
              customers who don't know the difference between a good engine and a
              piece of junk. But builders who stand behind their engines are aware
              of the remarkable decline in both quality and service that has taken
              place over the last couple of years. As a case in point, I was
              recently sent a set of unusable stroker rods -- about $300 worth of
              junk -- by California Import Parts, an outfit I'd done business with
              for several years. Rather than replace the junk with usable parts
              they chose to put me on Infinite Hold and to even ignore a letter from
              my attorney, uninterested in the future loss guaranteed by such shoddy
              practices.

              -R.S.Hoover
            • Jonsimik
              What s the story on dub & Porsche parts inter-changeability? jon ... Porsche ... wrist
              Message 6 of 7 , Jun 3, 2005
                What's the story on dub & Porsche parts inter-changeability?

                jon

                --- In AirVW@yahoogroups.com, "Chad" <cjstenson@a...> wrote:
                > Check out this link.
                > http://www.cbperformance.com/catalog.asp?ProductID=1340
                > It may help with determining what you will need for spacers. You'll
                > need to know your rod length. Use the deck height number in the
                > engine calculator found here:
                > http://www.cbperformance.com/enginecalc.html to determine compression
                > ratio.
                >
                > chad
                >
                > --- In AirVW@yahoogroups.com, "Bob" <bbells@f...> wrote:
                > > My engine was built around 1980. It is a 2180cc AeroVee, 82mm stroke,
                > > 92mm pistons. I am rebuilding it and using a new engine case,
                > > crankshaft, connecting rods, etc. The old case was filled with
                Porsche
                > > parts. I have noticed that current stroker 92mm pistons have the
                wrist
                > > pins higher up in the piston than non-stroker pistons. I have no idea
                > > if mine are like this. How can I confirm that my current pistons and
                > > cylinders will or will not work? And what the shims would be? Thanks!
                > > Bob
                > > MN
              • Bob
                Jon, on VW and Porsche interchangeability - It certainly was interesting opening it up. And, it helped me make the decision to replace the entire engine.
                Message 7 of 7 , Jun 3, 2005
                  Jon, on VW and Porsche interchangeability - It certainly was
                  interesting opening it up. And, it helped me make the decision to
                  replace the entire engine. Nothing in the logbook about it. Maybe the
                  Porsche parts made it last longer - Depending on how you read the
                  logbook it could be anywhere from 162 hours to slightly over 1000
                  hours. I'll be magnafluxing the crank in the next few days to see if
                  the prop strike cracked it (previous owners adrenaline rush, not
                  mine). Should be interesting. The crank looks like it is cast not
                  forged, pitted, but I'm not an expert. The VW crank and new bearings
                  I have seem to tightly fit all the holes and everything after taking
                  the Porsche stuff out. If the Porsche crank checks out I will replace
                  it and make an airboat with the engine. Having owned a Porsche I am
                  really not sure why anyone would use Porsche parts for anything where
                  they would need a modicum of reliability. I kinda thought the Porsche
                  engineers were over there in pubs trying to figure out how to make
                  various parts of the vehicle more complicated and prone to failure.
                  Can't see that degree of quirkiness without purposeful planning.


                  --- In AirVW@yahoogroups.com, "Jonsimik" <bigbajon@a...> wrote:
                  > What's the story on dub & Porsche parts inter-changeability?
                  >
                  > jon
                  >
                  > --- In AirVW@yahoogroups.com, "Chad" <cjstenson@a...> wrote:
                  > > Check out this link.
                  > > http://www.cbperformance.com/catalog.asp?ProductID=1340
                  > > It may help with determining what you will need for spacers.
                  You'll
                  > > need to know your rod length. Use the deck height number in the
                  > > engine calculator found here:
                  > > http://www.cbperformance.com/enginecalc.html to determine
                  compression
                  > > ratio.
                  > >
                  > > chad
                  > >
                  > > --- In AirVW@yahoogroups.com, "Bob" <bbells@f...> wrote:
                  > > > My engine was built around 1980. It is a 2180cc AeroVee, 82mm
                  stroke,
                  > > > 92mm pistons. I am rebuilding it and using a new engine case,
                  > > > crankshaft, connecting rods, etc. The old case was filled with
                  > Porsche
                  > > > parts. I have noticed that current stroker 92mm pistons have the
                  > wrist
                  > > > pins higher up in the piston than non-stroker pistons. I have
                  no idea
                  > > > if mine are like this. How can I confirm that my current
                  pistons and
                  > > > cylinders will or will not work? And what the shims would be?
                  Thanks!
                  > > > Bob
                  > > > MN
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