Automotive Intake Manifold – Boss 302 Independent Runner

Discussion in 'Lost foam casting' started by Al2O3, Apr 24, 2021.

  1. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Thank you Anders. I use 1.3% shrink for aluminum so the foam patterns are made 1.3% larger than the desired casting size.

    Anders Lundholm and BattyZ like this.
  2. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I needed another air filter base for a clear polycarbonate display lid but the foam patterns just aren’t rigid enough to be made separately so I did a variation on the first lid to cast with the second base. On this version I made some turning vanes that are positioned above each carb booster to help direct the inlet charge and any reversion pulse. The turning vanes are these conical looking shapes cut with a 2” ball nose router bit. I was sort of surprised how well the foam machined into the points.

    1 Cone.JPG 2 Cones.JPG

    Mounted up they looked like this…

    3 Cones Mounted.JPG 4 Cones Mounted.JPG

    ….and the opposite side of the lid was machined to make the cones more uniform wall.

    5 Top side lid 2.JPG

    I gated it essentially the same as the previous lid except the runners were more outboard because the cones were occupying the position used on the previous version and it was the only way I could come up with a viable degating strategy. The other significant difference is this base and lid is only 1/8” wall whereas the previous one was 3/16” wall.

    6 Gated.JPG

    The casting session was similar to previous run and came off well.

    7 Casting Aftermath.JPG 8 Raw casting.JPG

    After communing with my table saw and bandsaw, the lid and base parted ways.

    9 Seperated.JPG

    I cleaned up the remaining gating on the mill, touched up with abrasive disc, then media blasted them…..and then there were two.

    10 Finished Casting.JPG 11 Finished Casting.JPG

    One thing I thought was pretty interesting was how well those pointy cones cast. Seven out of eight of them looked like this. I had to be very careful handling them not to get stuck.

    12 Pointy Cone.JPG

    The very last one furthest from the sprue at the bottom of the mold looked like this, so I must have had the temp about right (1450F) for this large thin-walled part.

    13 Rounded Cone.JPG

    Michael, BattyZ, Ronny Bøe and 9 others like this.

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