The shifter is then removed from the mill, blown clean, and set up in a bench vise. To create the cast-look takes far more attention than simply trying to blast the part with any type of media. Kerr prefers to use a metal burr wheel for steel secured in an air-driven drill to create the texture. He tells us that an aluminum one can also be used but that it will create a far rougher surface. To achieve the grain pattern, a precise repetitive motion in the same direction should be used to lightly glide from left to right starting at the top of the shifter downward. If you stop, the wheel could create a divot on the section being worked. It's best to start off the metal and finish off the metal on the other end with each sweep to create uniformity. Once completed, Kerr sandblasts the part using basic play sand available at any hardware store. Once the part is completely clean, it is washed down with either brake cleaner or water to remove the majority of the sand residue. A final blow with an air line will remove the rest. The final look gives the perfect illusion of a cast part looking decades old.
Shifting gears to take on the fabrication of a traditionally-styled fuel block, Kerr begins with a 2-inch square by 4-inch long-block of solid T6061 billet aluminum. The stock is then coated in machinist's dye. The bottom of one end of the block was measured to establish the center for the fuel inlet. Using a height gauge on a granite layout table the mounting surface lines were measured and marked using a scribe at 1.2 inches from the top of the fuel block with a second mark at 0.575 inch from the top. This results in a 5/8-inch band for the mounting surface. The block was then moved to the First mill and secured in a Kurt vise to drill a 2-inch-deep hole in the base for the fuel inlet using a 7/16-inch drill bit. The hole was then blown clean, tapped with a 1/4-18 pipe thread, and an old fitting secured to allow it to be secured to the lathe. A small pilot hole was also measured and added using a 0.250-inch drill bit to the opposite end to secure it to the live end of the lathe. The block was then moved to the lathe making sure it was square on all edges when mounted. Since the block is rectangular, particular care needs to be taken to avoid shattering the cutting bits as the block is being turned. A facing insert tool was set up and cutting commenced below the mounting surface, removing 0.100 inch at a time. This step takes quite a bit of time to get the section completely round. To achieve the desired diameter of 1.875 inches, the cuts were adjusted to 0.050 inch till completed. Note that the total area being turned was 0.575 inch. The block was then reversed and the same amount was removed from the top while allowing the 5/8-inch mounting band to remain. Finally the block was coated with machinist's dye and measured using a Vernier caliper for stylish fins to be cut next with each being 1/8-inch thick. A total of eight fins were marked starting from the bottom of the block to create the layout.
Once lined up, beginning at the bottom of the block a 1/8-inch grooving tool was used. After moving the cutter in place lightly touching the block, Kerr "zeroes" out the handle dial to ensure the same will be cut, here the amount is 0.300 inch per fin. This amount is again confirmed with a dial indicator as each fin is completed. Kerr tells us that it's all about maintaining the accuracy and balance of the part as you move forward. The block was then flipped and re-secured in the lathe with a carbide bit used to add a neat bevel to the top of the block. The block was then removed from the lathe and secured in a vise to prepare to drill the fuel outlet holes. After measuring 2 inches from the bottom of the fuel block a 7/16-inch bit was used to slowly drill into the block, making sure to intersect the fuel inlet hole. While still on center, a center guide was then used to make sure the tap holes were perfectly straight for using a 1/4-18 pipe thread tap. The mounting surface was then finalized with a disc sander to round off the front sides for a clean look. The flat mounting surface was then drilled with a 0.159-inch drill bit and tapped with 10/32 thread. To complete the fuel block its surface was prepared in the same way as the shifter, giving it the old-time cast look of a part that would have been at home on a dry lakes racer in the late '40s and to us that's just plain bitchin.
19. Here you can see the upper and lower portions of the initial cuts to the fuel block completed.
20. With a quick spin in the lathe Kerr coated the body of the fuel block with machinist's dye to prepare it for its next set of cuts.
21. To mark the fins a Vernier caliper was used to measure them out. Starting from the bottom, eight fins were scribed in place, each 1/8-inch thick.
22. With an 1/8-inch grooving tool installed, Kerr meticulously makes his first cut to 0.300 inch depth starting at the bottom of the fuel block.
23. It's a good idea to keep a dial indicator on hand to measure from fin-to-fin as production moves forward to ensure all measurements are accurate.
24. The fuel block comes to life once the fins were completed, giving the part a very traditional vibe.
25. The fuel block was then reversed in the mill and a carbide tip blade was used to give the top edge a very subtle bevel.
26. With the block in a vise, a 7/16-inch drill bit was used to drill the fuel outlet hole 2 inches from the bottom of the block.
27. Carefully, the drill moves through the block making sure to intersect the fuel inlet hole.
28. Using an Enco disc sander with a 36-grit disc, the front sides are rounded off for a nice custom look while the rear mounting surface will remain flat.
29. A 7/16-inch drill bit was used to drill an additional fuel outlet hole.
30. With the block still secured in the vise, the holes were then tapped with a 1/4-18 pipe thread. Mounting holes were also drilled and tapped on the rear mounting face.
31. A metal burr wheel for steel was then used to begin the surface texturing process. Kerr slowly worked his way around the fuel block massaging all surfaces.
32. The worked-over fuel block (top) lets you see all of the completed surface preparation and once sandblasted the final product (bottom) looks like it was hand cast decades earlier.
33. There are a number of parts JoKerr Fabrication has started offering, including this downright bitchin carb topper for dual-quads, featuring extremely unique velocity stacks.