Exhaust Header Mockup Kit 1.75" Tube (44.45mm OD) – 219pc WORKSHOP

Exhaust header and manifold mockup blocks for 1.75" mandrel bent tube

Our largest kit, built for fabricators designing complex headers and manifolds in 1.75" OD mandrel bent tube (44.45mm). 219 magnetic mockup blocks let you route primaries around the block, chassis rail, steering shaft and turbo flange in plastic, confirm every clearance, then cut stainless once you already know the answer. Both 1D and 1.5D centreline radius bends are included, so tight and sweeping bends can be mixed in a single design.

What it does

• Mock up an entire eight cylinder header without running out of blocks
• Keep more than one project mocked up at a time
• Design equal length headers where primary length actually matters to the powerband
• Model the merge collector and confirm the collector angle before you cut
• Work around tight engine bay clearances, turbo positioning and wastegate routing
• Produce an exact cut list so you order the right mandrel bends and waste no stainless

Kit contents (219 pcs)

• 25 × 30° 1D
• 25 × 30° 1.5D
• 25 × 45° 1D
• 16 × 45° 1.5D
• 12 × 90° 1D
• 12 × 90° 1.5D
• 30 × 15 mm straight
• 25 × 25 mm straight
• 12 × 50 mm straight
• 8 × 75 mm straight
• 8 × 100 mm straight
• 8 × Flexible Flange Adapters
• 10 × Flat Pipe Measuring Gauges
• 2 × Pipe Guides
• 1 × Heavy Duty Plastic Carry Case

Tube compatibility

Matched to 1.75" outside diameter mandrel bent exhaust tube, 44.45mm OD. This is a tube kit, not a pipe kit. Tube is sized by its actual outside diameter, while NPS pipe is sized by nominal bore, so 1.75" tube is not interchangeable with our 1.25" or 1.5" NPS SCH10S kits. If you are building in schedule 10 pipe, choose one of those instead.

Bend radii on tube

On tube, D refers to the actual outside diameter. 1D is therefore a 44.45mm centreline radius and 1.5D is 66.7mm. This differs from our NPS pipe kits, where D follows the nominal size rather than the OD, so blocks will not match across the two systems.

This kit ships with 1D and 1.5D bends. A wider 2D radius (88.9mm CLR) is available separately in our 1.75" tube bend add-on packs, for long sweeping primaries where flow matters more than packaging.

Header mockup, step by step

1. Mount the flange adapters to your head flange or turbo flange
2. Snap bends and straights together, rotating each joint to clear obstructions
3. Adjust until every primary is routed and the lengths are balanced
4. Count your blocks for the cut list, then cut, tack and TIG weld to match

Specification

Made to order in Britain

Every kit is produced to order in our own workshop rather than pulled off a shelf. That is why we can supply centreline radii and tube sizes the imported kits do not offer. Need a size that is not listed? Get in touch and we will quote it.

FAQs

Do I need WORKSHOP or BUILDER?
BUILDER at 136 pieces suits a four or six cylinder build. WORKSHOP at 219 suits eight cylinder header work, or a shop running several projects at once.

Can I get 2D bends for this kit?
Yes. Our 1.75" tube add-on packs cover 30°, 45° and 90° in 1D, 1.5D and 2D, so you can add the wider 88.9mm CLR radius to the 1D and 1.5D blocks supplied here.

What are the flat pipe measuring gauges for?
They let you transfer primary lengths and cut positions from the mockup straight onto real tube, so the cut list you generate on the bench is the one you cut to.

Will these blocks work with my 1.25" or 1.5" NPS kit?
No. Tube and pipe are different diameters and each size is a separate system. Blocks will not connect across sizes.

Is the carry case included?
Yes. The heavy duty case is supplied with this kit and keeps the blocks sorted between jobs.