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.
  3. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Finally got around to assembling the video for the filter assemblies.

  4. Mach

    Mach Silver Banner Member

    Very nice, will we get to see this bolted to a go-faster in the near future?
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Well, at some point yes, but still a bit in the future. There is a companion engine development program in the works by the fellow that will eventually own the system. Unfortunately, I broke my ankle a few weeks ago, am surgically pinned backed together, in a cast, and ordered to be off it for another four weeks so that has slowed me down a bit. About the only thing I can do to remain productive and keep from going crazy is write CAM programs and work on my CAD skills. So far I have completed pattern programs for 16 new parts in the queue and counting. When I get back on my feet, it's going to be CNC Router and Casting Pa-looza!

    Stanislavz and Anders Lundholm like this.
  6. Mach

    Mach Silver Banner Member

    Sorry to hear that and hope you are back at it soon enough. I do find it humorous that even at reduced speed, you are more productive than I am at full speed. Looking forward to casting palooza. :)
  7. Hopes to see you on feets soon!! Take care!
    You learn us so much !!!
  8. Get well soon Kelly, hope you make a full recovery.
  9. BattyZ

    BattyZ Silver Banner Member

  10. Monty

    Monty Copper


    Let me just a former Shelby modded '66 Fastback owner, I'm simply drooling over this. I saw your videos on YouTube and that led me here. Awesome....simply awesome!

  11. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Thanks for the well wishes fellas. One month post-surgery and first time since I was actually able to accomplish something in the shop.

    72 Ankle.JPG

    Small project, but at least it's something. It’s a linkage arm for the induction system. I only need one piece but by the time I set up and change tools once I figured three were about the same total time.

    73 CNC.JPG

    Space is very tight between the carbs. I made two versions. The rod ends mount on the end of one and on top the bosses of the other. One version is just one-sided machining, the other, two-sided, so it had some registration holes/pegs.

    74 Top.JPG 75 Bottom.JPG

    Cut one of each free from the holding tabs and cut the ribs with a razor knife. Wasn’t worth to extra programming to cut the slope on the rib. The castings will get a couple ball bearings in the center boss.

    75 One Each.JPG 76 One Each.JPG

    Moving slow. Baby-steps……quite literally. Still more frustrated than a one-legged man at an ass-kickin’ contest but at least it’s something.

  12. BattyZ

    BattyZ Silver Banner Member

    Nice design. Good use of splines!

    For the steep slope side wall I have learned to love tapered endmills. Need to have your tool change procedure rock solid but they make quick work! I have 1, 3 and 7 degree tapered variants.

    I concur!
  13. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Roger that. I was thinking I'd (3-jaw) chuck on the central boss so no draft/taper ;)

  14. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I had a whether window today and took the opportunity to cast a number of patterns I previously made. I made these small idle stops. There is a left and right hand version. I nested them and blasted out a few panels.

    78 Idle Stop Nested.JPG

    Then cut them out of the panel

    79 Idle Stops.JPG

    Here’s where they go on the carb

    80 Idle Stop on Carb.JPG

    Tree’d them up along with the linkage arms, dipped and cast them.

    81 Idle Stop Coated.JPG 82 Idle Stop Degated.JPG 83 Linkage Arm.JPG

    …….and along with the other castings, the day’s bounty

    84 The Days Bounty.JPG

  15. BattyZ

    BattyZ Silver Banner Member

    I really like how you snuvk in the rim casting, great haul overall.

    The tree-ing of the small parts looks very useful. Results to boot!
  16. And this is the project that clued me into the existence of this site - really great work, and not the least of which because you're messing with incredibly cool rare Trans-Am intent parts.

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