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ports in cast iron heads

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  • A. Kovatsch
    Yesterday I have been to a workshop for machining engine parts to talk about intake channels for my iron head Ford. The man said that they don t have time for
    Message 1 of 10 , Dec 1, 2003
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      Yesterday I have been to a workshop for machining
      engine parts to talk about intake channels for my iron
      head Ford. The man said that they don't have time for it
      since it takes an etrnity to polish ports in this head, if it
      was alu they'd gladly do it...

      I asked if I do it myself, and they said that it will take
      "all winter of polishing" till I make a significant difference...

      How true si this?


      bye all,
      sascha
      http://www.jestartech.com
    • Ernest Buckler
      Sascha, I d say that the proper cutters and grinders, plus a die-grinder with plenty of horsepower would help a lot. Start with 1/4 shaft (or metric equiv.,
      Message 2 of 10 , Dec 1, 2003
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        Sascha,
        I'd say that the proper cutters and grinders, plus a die-grinder with plenty
        of horsepower would help a lot. Start with 1/4" shaft (or metric equiv., of
        course) carbide burrs in various shapes, to get close to the depth you want,
        then finish up with grinding stones and rolls. You'll need lots of them, in
        various grits. You won't find the burrs or the rolls at your local hardware
        store, definitely industrial supplies. These are the spiral rolls of
        grinding cloth wound into a tight cylinder that thread onto a pointed
        mandrel, usually 1/4" shaft. But that's for finish work, after you've done
        the cutting. Be VERY careful you don't knick the valve seats...!!!!! Also
        much easier if the guides are removed, if you're going to go beyond just
        matching ports. Also take the time to make a simple holder that can be
        locked at any angle, a great time saver.

        I'd also suggest starting on a JUNK head, just do one and see how much time
        it takes, how the cutters like to grab and pull, etc. See if you're up for
        it. I paid to have basic matching and smoothing on my 460 Ford V8, plus
        install valve seats for unleaded fuel, total cost was something like $300,
        and the ports looked much nicer than before, not to mention matching the
        manifolds.

        Ernest Buckler




        ----- Original Message -----
        From: " A. Kovatsch" <jestartech@...>
        To: <mc-engine@yahoogroups.com>
        Sent: Monday, December 01, 2003 10:59 PM
        Subject: ports in cast iron heads


        Yesterday I have been to a workshop for machining
        engine parts to talk about intake channels for my iron
        head Ford. The man said that they don't have time for it
        since it takes an etrnity to polish ports in this head, if it
        was alu they'd gladly do it...

        I asked if I do it myself, and they said that it will take
        "all winter of polishing" till I make a significant difference...

        How true si this?


        bye all,
        sascha
        http://www.jestartech.com



        unsubscribe: mailto:mc-engine-unsubscribe@yahoogroups.com

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      • Anders Brink
        ... Check out http://www.sa-motorsports.com/diyport.htm /anders @ http://andersbrink.tk/
        Message 3 of 10 , Dec 2, 2003
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          " A. Kovatsch" wrote:
          >
          > Yesterday I have been to a workshop for machining
          > engine parts to talk about intake channels for my iron
          > head Ford.

          Check out http://www.sa-motorsports.com/diyport.htm

          /anders @ http://andersbrink.tk/
        • bjammin@i-plus.net
          ... Let me put a perspective on this. Grumpy Jenkins went on record 35 years ago as stating that finer polish than can be done with 280 grit was a big waste
          Message 4 of 10 , Dec 2, 2003
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            >the expert said that it can be polished to the amounth that could
            >be described as "cut", but it is not necessary since
            >smoothing the surfaces can be enough.

            Let me put a perspective on this. Grumpy Jenkins went on record 35 years
            ago as stating that finer 'polish' than can be done with 280 grit was a big
            waste of time.

            As for turbulence, it's axiomatic that ports should have laminar flow;
            turbulence uses up energy that could otherwise promote cyl filling. The big
            reason to not polish ports too fine has much more to do with heat transfer
            from port walls into the mix, which is seldom atomized perfectly traveling
            thru the port; that extra few calories does make quite a diff. Also, the
            turbulence induced by 280 grit finishes is minimal and most likely doesn't
            extend past the boundary layer anyhow.

            For my personal experience, ports should 1) have all casting flaws removed,
            2) have guide bosses pared down to a bit over the guide dia at the guide
            tip, 3) be tapered from carb to valve, 4) have intake seats narrowed about
            40-50%, and 5) have any and all other metal removed from the top only, esp
            downstream of guide.

            If you're into anti-reversion, you can make the port bigger than the carbie
            hanger flange and do a special boogie bit on the valve backside, consisting
            of a circular trench just inside of the seat (yes, it works on intakes too).

            Regards, Hoyt McKagen

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          • cider_power
            ... Its not. As somone has already said, decent equipment makes the job simple. Using a drill and cheap stones will end up costing more in the long run than
            Message 5 of 10 , Dec 2, 2003
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              --- In mc-engine@yahoogroups.com, " A. Kovatsch" <jestartech@p...> wrote:
              > Yesterday I have been to a workshop for machining
              > since it takes an etrnity to polish ports in this head, if it
              > "all winter of polishing" till I make a significant difference...
              >
              > How true si this?

              Its not. As somone has already said, decent equipment makes the job simple.
              Using a drill and cheap stones will end up costing more in the long run than
              buying an industrial die grinder and the stones an burs you will need for the job.
              Dont be tempted by steel burs, especialy for cutting cast iron, carbide are 10
              times the price but last a lot more than 10 times longer but they chip easily so try
              to avoide any chattering and do your best to keep away from the valve seats. If
              its your first time trying this, your going to damage the valve seats so alow for
              having them re-cut. Use plenty of coolant (water emulsion or light oil, ask the
              supplier. They will help you with any questions you have on tools and stones, if
              they dont or dont know what your talking about then take your business
              elsewere). Before you start, expect to have to scrap a head, its all to easy to
              break into a drilling or just go to far. If there is any info on where to cut and what
              to watch out for then find it, somone else has made mistakes to find all that out.
              Check up on everything you intend to do.There are plenty of web sites with all
              the info you will need on porting. Find what you want to know, then check other
              sites to see if they agree. There are a lot of different oppinions floating around
              but these days its all "tunning by numbers". Dont go mad!. Taking out the
              restrictions in the ports, polishing the ports and matching the manifolds will make
              a big change but the cam, intakes, exhaust, comp.....ect. ect. ect. all have to
              work together to get any real gains. If you go at the head or any other part step
              by step with patience then your going to end up with a damn good engine. Best
              of luck with it.

              Stan.
            • JOHN MEAD
              ... The best stones to use are cone shaped wrapped grit paper. They are cheap and as the outside grit wears off there is another layer under it. John Mead
              Message 6 of 10 , Dec 2, 2003
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                --- cider_power <ciderpower@...> wrote:
                > Its not. As somone has already said, decent
                > equipment makes the job simple.
                > Using a drill and cheap stones will end up costing
                > more in the long run than
                > buying an industrial die grinder and the stones an
                > burs you will need for the job.

                The best "stones" to use are cone shaped wrapped grit
                paper. They are cheap and as the outside grit wears
                off there is another layer under it.

                John Mead
              • A. Kovatsch
                after posting this question to the groups, I talked to the VW tuner about ports job, and he said something similar to this. What I need in the intake ports is
                Message 7 of 10 , Dec 2, 2003
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                  after posting this question to the groups,
                  I talked to the VW tuner about ports job,
                  and he said something similar to this.

                  What I need in the intake ports is laminar not turbulent flow.

                  non-smooth surface of channels gives turbulence, and therefore,
                  the effective cross section for the flow is nor what I see or measure,
                  but the same-the turbulence layer.
                  remove this layer is pretty much enough for high perf as
                  far as ports are considered, lets not forget the chance of "finding water"
                  in an unknown head : 0

                  the expert said that it can be polished to the amounth that could
                  be described as "cut", but it is not necessary since
                  smoothing the surfaces can be enough...

                  I guess I just wasn't concentrated well on the problem - thanks all : )
                   

                  bye,
                  sascha
                  http://www.jestartech.com
                   

                  Ray & Sonja Crenshaw wrote:

                  > >> The man said that they don't have time for it
                  > >> since it takes an etrnity to polish ports in
                  > >> this (cast iron) head
                  >
                  > > I'd say that the proper cutters and grinders, plus a
                  > > die-grinder with plenty of horsepower would help a lot
                  >
                  > Why not do what Smokey Yunick used to do? Back in the 50's, NASCAR (US
                  > sanctioning body for <ahem!> "stock car" racing) didn't allow port
                  > polishing. Smokey's six-cylinder flathead Hudson Hornets outran all comers
                  > for several years, so the idea has been tested in combat and found to work.
                  >
                  > "What was it" you say?
                  >
                  > Smokey just painted the Hornet's ports, then shined up the paint.
                  >
                  > Give 'er a try, and send me a check for my percentage of the money you save.
                  >
                  > jrc in SC
                  >
                  >
                  > unsubscribe: mailto:mc-engine-unsubscribe@yahoogroups.com
                  >
                  > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                • Ray & Sonja Crenshaw
                  ... Why not do what Smokey Yunick used to do? Back in the 50 s, NASCAR (US sanctioning body for stock car racing) didn t allow port polishing.
                  Message 8 of 10 , Dec 2, 2003
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                    >> The man said that they don't have time for it
                    >> since it takes an etrnity to polish ports in
                    >> this (cast iron) head

                    > I'd say that the proper cutters and grinders, plus a
                    > die-grinder with plenty of horsepower would help a lot


                    Why not do what Smokey Yunick used to do? Back in the 50's, NASCAR (US
                    sanctioning body for <ahem!> "stock car" racing) didn't allow port
                    polishing. Smokey's six-cylinder flathead Hudson Hornets outran all comers
                    for several years, so the idea has been tested in combat and found to work.

                    "What was it" you say?

                    Smokey just painted the Hornet's ports, then shined up the paint.

                    Give 'er a try, and send me a check for my percentage of the money you save.

                    jrc in SC
                  • cider_power
                    ... Thats a hornets nest of a statement to make, its been debated for at least 40 years and there has been as much proof for one side as the other. Some tuners
                    Message 9 of 10 , Dec 4, 2003
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                      --- In mc-engine@yahoogroups.com, "A. Kovatsch" <jestartech@p...> wrote:
                      > after posting this question to the groups,
                      > I talked to the VW tuner about ports job,
                      > and he said something similar to this.
                      >
                      > What I need in the intake ports is laminar not turbulent flow.
                      >
                      Thats a hornets nest of a statement to make, its been debated for at
                      least 40 years and there has been as much proof for one side as the
                      other. Some tuners will shape a port and sand blast the surface to get
                      the desired finnish, while others will not be happy untill they can
                      see their face in it. I try to polish the exhaust to a near mirror
                      finish, it does reduce carbon buildup to a small degree and leave the
                      intakes fairly rough unless there are nesasary restrictions in which
                      case a polished finish should, in theory, allow a little more flow at
                      the cost of fuel atomisation. In practice though, you could bugger
                      about for a month finding the best finish to gain 1 percent and lose 5
                      by not spending enough time on somthing like the jetting or ignition.

                      Stan.
                    • kastanis
                      Maybe a little off topic by now, but is it even possible to have laminar flow in intake ports? The gas velocity would have to be extremely low.
                      Message 10 of 10 , Dec 4, 2003
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                        Maybe a little off topic by now, but is it even possible to have laminar flow in intake ports? The gas velocity would have to be extremely low.

                        -----Original Message-----

                        > Date: Thu Dec 04 12:09:19 PST 2003
                        > From: "cider_power" <ciderpower@...>
                        > Subject: Re: ports in cast iron heads
                        > To: mc-engine@yahoogroups.com
                        >
                        > --- In mc-engine@yahoogroups.com, "A. Kovatsch" <jestartech@p...> wrote:
                        > > after posting this question to the groups,
                        > > I talked to the VW tuner about ports job,
                        > > and he said something similar to this.
                        > >
                        > > What I need in the intake ports is laminar not turbulent flow.
                        > >
                        > Thats a hornets nest of a statement to make, its been debated for at
                        > least 40 years and there has been as much proof for one side as the
                        > other. Some tuners will shape a port and sand blast the surface to get
                        > the desired finnish, while others will not be happy untill they can
                        > see their face in it. I try to polish the exhaust to a near mirror
                        > finish, it does reduce carbon buildup to a small degree and leave the
                        > intakes fairly rough unless there are nesasary restrictions in which
                        > case a polished finish should, in theory, allow a little more flow at
                        > the cost of fuel atomisation. In practice though, you could bugger
                        > about for a month finding the best finish to gain 1 percent and lose 5
                        > by not spending enough time on somthing like the jetting or ignition.
                        >
                        > Stan.
                        >
                        >
                        >
                        > unsubscribe: mailto:mc-engine-unsubscribe@yahoogroups.com
                        >
                        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                        >
                        >
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