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First attempt at facing a head.

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  • First attempt at facing a head.

    Hi all I am new to this game and today I had my first shot at facing a head.

    I used the cheapO 4 cutter face mill that came with the mill. I now understand why people opt for a flycutter.

    My first cuts where pretty deep and I ran the machine really slow. I fiddled around and found that flat out was the best speed whilst only removing a bee's pecker of metal. I think it gave an OK finish not great tho.
    I have attached a photo any tips would be greatly appreciated.


  • #2
    Wd-40

    Same cutter - high(er) speed and feed but lubricate (plenty!!) with WD-40 or paraffin (kerosene here and UK) - but do clean off the aluminium which will have really stuck to your cutters (due to cutting dry).

    Be sure that the mill is properly "trammed" else you will or may get a "step" where the cuts over-lap. This may cause a leak between cylinders, or between water jacket holes or between cylinders and water cavity holes etc.

    If this is the case, use a fly-cutter with good rakes and clearances and a rounded nose - and fine hone then edges with a diamond "(cheap)" honing-stick.

    Comment


    • #3
      In my (limited) experience here in my home shop, the couple of multi-cutter face mills I have (one of them like you have) the finish is not nearly as good as I am able to get with a fly cutter. I dont doubt that with the proper cutter and inserts a beautiful finish could be had - translated- with enough money! Since I have such good luck with a fly cutter, I,m not likely to pursue finding that 'ideal' face mill.

      I use the cheapo brazed carbide lathe cutters after a good crisp edge is put on it with a diamond wheel. I can tell by the change in the "hammering" sound when I need to re-touch the edge on them and when kept sharp, get an almost mirror finish.

      And like Tiffe said, use some lube,- kerosene or WD - WD is convenient in the spray can. ---- Hmmm, this IS an aluminum head innit?
      If everything seems to be going well, you have obviously overlooked something........

      Comment


      • #4
        That looks like an iron head to me, not aluminum. In that case cut it dry, lube or collant and iron swarf just makes a mess. How many passes did you need to make?
        James Kilroy

        Comment


        • #5
          Lookin at it a little closer, kilroy, it just may be iron, in which case you right....
          If everything seems to be going well, you have obviously overlooked something........

          Comment


          • #6
            Originally posted by oldtiffie
            Same cutter - high(er) speed and feed but lubricate (plenty!!) with WD-40 or paraffin (kerosene here and UK) - but do clean off the aluminium which will have really stuck to your cutters (due to cutting dry).

            Be sure that the mill is properly "trammed" else you will or may get a "step" where the cuts over-lap. This may cause a leak between cylinders, or between water jacket holes or between cylinders and water cavity holes etc.

            If this is the case, use a fly-cutter with good rakes and clearances and a rounded nose - and fine hone then edges with a diamond "(cheap)" honing-stick.

            its cast iron mate.

            Comment


            • #7
              Duly admonished

              Oops.

              Thanks jkilroy, Bill Pace and michael3fingers - appreciated.

              My cock-up (SNAFU?) there.

              I assumed that it was aluminium because of the better finish at higher speeds.

              I should have asked and waited for an answer.

              Self severely admonished by same self.

              Comment


              • #8
                Van Norman head broaching machines do the full face of the head in one pass. Doing several passes on the surface of the head may not give a good seal surface. You need a cutter that will cover the full width of the head and then some. It's the same when you deck a block.

                Multiple passes are not good surfacing heads.
                It's only ink and paper

                Comment


                • #9
                  thanks carl

                  I have ordered a MT3 fly cutter that will accept a 3/8 square cutter. I only about 75mm of it pokin out to get the whole thing done in 1 swing. I am in Aus so it will take a while to get here from the UK but I will post photos once its done. thankyou for your feed back.

                  Comment


                  • #10
                    Ive occasionally wondered why heads are not ground on a Surface grinder?

                    anyone know?

                    Dave

                    Comment


                    • #11
                      Originally posted by small.planes
                      Ive occasionally wondered why heads are not ground on a Surface grinder?

                      anyone know?

                      Dave
                      Most likely one reason is that they will be too smooth for good sealing with the head gasket. I'm sure that manufacturers could cut o'ring seats in the head or block but its not just the cylinders that need sealing. You also have to seal all of the coolant and oil passages. The gasket will need something to bite on. In the US industry the standard machine for machining the mating faces was Cincinatti Broaches. The tool sets for a block or haed broach had to be about 16 feet long IIRC. They left a fairly smaooth surface. Later when lightweight castings came into play much less aluminum blocks and heads a lot of the face machining switched to milling operations (aluminum has to be milled). These operations when set up right did not leave a mirror finish. Again the reason was to give a some bite to gasket. Sometimes I would look at say the finish on a 4.0 head for a Jeep and wonder as it looks like a fish scale.
                      Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

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                      • #12
                        Originally posted by small.planes
                        Ive occasionally wondered why heads are not ground on a Surface grinder?

                        anyone know?

                        Dave
                        In my yoot I was an automotive machinist and we had a large tub grinder that we could use to single-pass heads and engine blocks. The wheel was huge in diameter - much larger than the width of the heads, and on a vertical shaft.

                        It could take 30 minutes to set up a badly warped head but 5 minutes to produce a flat mirror surface, often in a single pass. It's amazing how many cracks you find in the webbing between side-by-side exhaust valves after they're surfaced. Never finished grinding a Mercedes-Benz Diesel head because they were always cracked.

                        Comment


                        • #13
                          Talk to most OEMs and aftermarket gasket manufacturers and the tech reps will tell you smoother is better. That a gasket needs something to grab is old shop legend. Today, especially on aluminum heads, there is quite a bit of movement and a smoother gasket surface is what is wanted. Also, many fewer head bolts are used than in the old Ford flathead days.

                          Surface grinders are not used because they're slow, mainly designed for steel, and the varying width and length of heads and blocks don't fit the tables of any but the larger grinders.

                          Bottom line, automotive machine shops work dirt cheap, have the correct tooling, know what they are doing, can find the cracks most heads have these days, so kids, don't try heads at home.

                          thnx, jack vines

                          thnx, jack vines

                          Comment


                          • #14
                            Originally posted by small.planes
                            Ive occasionally wondered why heads are not ground on a Surface grinder?

                            anyone know?

                            Dave
                            in this instance because I dont have one

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