Photo 5 — The Gear Tie is laid down against the tubing and the bend marks are transferred.
Photo 6 — The first segment in our tubing pattern is straight down and the offset was formed to route between the firewall, exhaust manifold (covered in high temperature woven wrap) and the engine's head. There are no rules about how much of a bend is needed. In general, gentle bends are easier to make and are encouraged. Every project has its constraints in its design. Note the reference line on the brass tubing to aid in keeping bends on the flat.
Photo 7 — More bend marks are transferred to the brass line. Note that the reference line on the end has rotated.
Photo 8 — Bends marks are again transferred to the brass tubing, this time with the tubing rotated to follow the pattern.
Here are some things to consider when making the pattern: 1) angle of the bends, 2) location of the bends (from a starting point), and 3) angular reference where these bends occur (also referred to as Rotation Angle). In this case, the starting point is the fitting under the oil filter. Since we wanted our tube to remain flat, to avoid bending our tubing to some unwanted direction, we placed a reference line on the tube where it can be easily seen while fabricating the tubing (Photos 6 & 7). The first two bends (i.e. the offset to clear the head) are in line with each other so a reference line is made 90 degrees to the bends. This oil line tubing project uses brass tubing from Restoration Supply Company. It is sold in eight foot lengths. While it is possible to cut an approximate total length of the tube and begin the flaring and bending steps, it makes more sense to work with the entire length of tubing, flaring one end first and making your bends from that point makes sense. Should something go wrong and you have to start over again, you want the piece of tubing to be as long as possible so that you don't come up short.
Flaring — The composition of a double flare end is shown in Photos 9 & 10. The end is first widened to form the outside angle while the next step folds the tip into itself. The flaring tool set used is shown at Photo 11. The tubing vise holder should be secured in your bench vise while the length of tubing is supported (Photo12). Photo 13 shows the tubing clamped into the holder with the appropriate amount of tubing protruding. Use the forming insert as a gauge for how much the tube must protrude. Using the cone vise and the forming insert, the tubing's end is drawn to full closure to make it into a shape of a bubble. Considerable force is required to create the bubble in the tubing. Employing an extension will make this task much easier (Photos 14-15). After the bubble has been formed (Photo 16) the insert is removed and the cone vise is again screwed onto the tubing to form the inside of the flare (Photo 17). The completed flare is at Photo 18.
Photo 9 — Close-up side view of a double flare. The cut into the flare's tip is another reason why this tubing could not be used.
Photo 10 — Top down close-up view of the same double flare.
Photo 11 — This Flare forming tool from Oldforge makes both single and double flare ends into the tubing ends. This set includes a multi size tubing holder (vise), different size forming inserts, and a cone shaped vise former. The Flaring kit shows the tubing vise which handles 3/16, 1/4, 5/16, 3/8 and 1/2 inch sizes. The five black disks with small dowels are the Flare formers for each of the sizes. The cone shaped vise former is used to set the inner flare when performing a double flare.