Designed specifically for rotary engine fabricators, the SPAN Racing Technology Billet Exhaust Manifold Flange provides superior fitment, durability, and weldability for custom exhaust manifold construction.
Manufactured in-house in Saitama, Japan from premium SUS304 stainless steel, each flange features an integrated welding register that simplifies fabrication while helping maintain precise alignment during the welding process.
Unlike conventional flat-cut flanges, the recessed pipe seat allows the exhaust tubing to transition smoothly into the port, promoting improved exhaust flow while increasing welding surface area and overall strength.
Key Features
Designed for Mazda Rotary Engines
Compatible with:
- Mazda 13B
- Mazda 20B
- Mazda 26B
The split-flange design makes it suitable for virtually all Mazda rotary engine configurations.
Premium SUS304 Stainless Steel
Precision CNC machined from high-quality SUS304 stainless steel, offering excellent corrosion resistance, strength, and long-term durability in high-temperature exhaust environments.
Integrated Welding Register
Each flange features a precision-machined pipe register designed to accept 50 mm exhaust tubing.
This design:
- Simplifies tube positioning during fabrication
- Improves weld consistency
- Helps minimize flange distortion during welding
Improved Exhaust Flow
Unlike traditional flat flanges where the tubing is simply butt-welded to the flange, the recessed pipe seat creates a smoother transition into the exhaust port, reducing flow disruption and improving exhaust efficiency.
Optimized Thickness
- Base flange thickness: 8.7 mm
- Overall thickness with welding register: 13.5 mm
The increased material thickness provides excellent rigidity while maintaining reliable sealing under extreme exhaust temperatures.
Manufactured in Japan
Designed, CNC machined, and finished in-house by SPAN Racing Technology in Saitama, Japan.
Fitment
- Mazda 13B Rotary Engine
- Mazda 20B Rotary Engine
- Mazda 26B Rotary Engine
Notes
- Compatible with 50mm exhaust tubing
- Split-flange design
- Sold individually
- Please order the required quantity for your manifold configuration
- Professional fabrication and welding are recommended
Included
- 1× SUS304 Billet Exhaust Manifold Flange
To International Customers
International shipping costs, customs duties, and import taxes are not included in the item price.
We recommend contacting us for a manual shipping quote before completing your purchase.
Some products are manufactured to order. Please contact us to confirm current availability and estimated lead time before placing your order.
SPAN Racing Technology
info@span-racing.com
