Manifold Mockup Kit

Lay the run out in plastic first, then cut steel once. Every piece clips into the next and turns to any angle, so you can build a runner on the car, try it against the chassis, mark it and take it apart again.

How it works: each piece has a socket on one end and a six-finger clip spigot on the other. Push them together until they click, then turn them to clock the run. Every socket has rotation marks every 15° (longer at 45° and 90°, the wide one is 0° on the heel of the bend), and the pointer behind each spigot reads against the next piece's marks — so you can write a run down and build it in steel exactly. The angle is engraved on every bend and the length on every straight.

Start at the head: the head port adapter drops over a port's two exhaust studs (open slots, M8 or M10 with a washer). Slide it until the socket sits on the middle of the port — notches on the plate's edges mark its centre line — snug the nuts, and clip the first piece in.

In every kit: 22.5°, 45° and 90° bends in short radius and long radius, straights of 25, 50, 75, 100 and 150 mm (socket face to spigot shoulder), and the head port adapter. The outside diameter is true to the pipe or tube.

Sizes: 1¼" pipe (42.2 mm OD, bends at 31.75 / 47.6 mm centreline radius), 1½" pipe (48.3 mm OD, 38.1 / 57.2 mm), 1¾" OD tube in 16 gauge (44.45 mm, 44.5 / 66.7 mm) and 2" pipe (60.3 mm OD, 50.8 / 76.2 mm). SCH 10 and SCH 40 share the outside diameter and differ only in the bore.

Printed in PETG. It's a mockup: keep it away from the weld and off a hot engine, because PETG softens at about 80 °C.