Designing tubular headers for the 1UZFE V8 engine inside the tightly packaged front chassis on the 620 build brought a considerable number of challenges. Systems like the front coilover bellcranks, upper control arms mounts, inner frame rails and steering linkage all needed to be considered to make sure there was enough serviceable room for the headers to live while also being removed if needed. Spending considerable time on the design was able to produce mirror image headers which would really expedite the time spent with sizing and cutting all the primary tubes for each side.

Starting with one off flanges designed from scratch, I made sure to incorporate tall and thin weld lip profiles around the primary holes to aid in welding the tubes to the much thicker weld flange. At the tail end of the headers I was working with uncommon tubes sizes for both the primaries and the v-band outlet, which required something special to be done with the collectors. Reaching out to the metal printing gurus at MIMO Technik, I designed a printable lofted collector profile which they DMLM printed from 625 Inconel.

Jigging the headers was a straightforward process, designing and laser cutting a steel framework to locate the flanges and also capture the collector ends on a removable locating ring. To precisely cut all the primary profiles, 3D printed jigs were designed and printed to securely clamp onto pre determined mandrel bent profiles, and provide a clear and easy cutting edge to trim the parts to their exact shape.

Once all the pieces were ready and test fit, the primaries were sequence and back purge welded by good friend Dominic Markiewicz, and the primaries welded to the flanges and collectors using a spare cylinder head to hold the flange’s shape as best possible. Fitment on the motor and inside the chassis was amazing, just as the CAD had shown on the digital side. The welding and printed cutting jigs were stored away, making this header set something that could easily be put into production use if needed.