Exhaust Header Flange, 1-5/8 Center, Pair

OVERVIEW

When you are fabrication a custom exhaust system for your air-cooled powerhouse, the precision of your components makes the difference between a high-performance machine and a leaky, frustrating mess. These EMPI 1-5/8 inch center exhaust header flanges are the gold standard for builders who refuse to compromise on structural integrity. Designed specifically for larger diameter performance tubing, these flanges provide the necessary foundation for constructing custom headers, merging collectors, or adapting specialized mufflers to your existing setup. Whether you are building a high-revving street engine or a rugged off-road beast, these heavy-duty flanges ensure that your exhaust pulses flow smoothly from the head to the tailpipe without the turbulence caused by mismatched or flimsy mounting surfaces. At Appletree Automotive, we know that a custom build is only as strong as its weakest weld, which is why we offer these precision-stamped pieces to ensure your fabrication project starts on the right foot.

Durability and heat management are paramount in the high-temperature environment of a Volkswagen engine bay, and these flanges are engineered to withstand the thermal cycles common in performance applications. Manufactured from thick, high-quality mild steel, they offer excellent weldability for both MIG and TIG processes, allowing for a deep, penetrating bead that won''t crack under the vibrations of a flat-four engine. The 1-5/8 inch center bore is perfectly sized for performance-oriented extractors, providing a seamless transition for exhaust gases. By using a pair of these flanges, you have the flexibility to create a symmetrical dual-exhaust system or a high-flow single extractor setup that looks as professional as it performs. Don''t settle for thin, stamped-out junk that warps the first time it gets hot; invest in the heavy-duty hardware that professional builders use to keep their systems sealed tight and sounding right.

FITMENT

• Volkswagen Type 1 Beetle: All years utilizing 1-5/8 inch performance exhaust tubing.
• Volkswagen Type 2 Bus / Transporter: Custom exhaust applications for 1600cc to 2332cc engines.
• Volkswagen Type 3 Fastback, Squareback, & Notchback: Custom performance exhaust builds.
• Volkswagen Karmann Ghia: Performance street and racing exhaust systems.
• Dune Buggies & Sand Rails: Universal fitment for custom header fabrication on air-cooled engines.
• VW-Based Trikes: Ideal for adapting custom mufflers or turn-outs to performance headers.

SPECS

• Product Brand: EMPI
• Part Number: 2505-12
• Quantity: Sold as a pair (2 Pieces).
• Center Hole Diameter: 1-5/8 inches (1.625").
• Material: Heavy-duty mild steel for maximum weldability and durability.
• Flange Thickness: Engineered to resist warping under high heat.
• Bolt Pattern: Standard 2-bolt VW exhaust pattern.
• Finish: Raw steel (ready for welding and high-temp coating).
• Application: Custom header construction, exhaust repairs, and flange replacement.

PRO TIPS

1. Proper Surface Preparation for Superior Welds

Before you strike an arc, it is absolutely vital to prep these flanges properly. Even though they arrive in a raw state, there can be residual oils or surface oxidation from the manufacturing and shipping process. Use a flap disc or a wire wheel to clean the area around the center bore where the tubing will seat. If you are TIG welding, go the extra mile and use acetone to wipe down the flange and the tubing. A clean surface ensures a weld that isn''t just aesthetically pleasing, but one that is structurally sound and free of porosity, which is the leading cause of exhaust leaks in custom-fabricated systems.

2. Preventing Thermal Warpage During Fabrication

One of the biggest mistakes builders make is welding the entire circumference of the tube to the flange in one pass. The intense heat can cause the flange to warp, meaning it will never seat flat against the gasket, leading to a permanent leak. To avoid this, bolt the flange to a spare cylinder head or a thick piece of scrap steel plate before welding. This acts as a heat sink and mechanical restraint. Use a "stitch" welding techniqueweld a small section, move to the opposite side, and let it cool slightly between passes. This keeps the mounting surface true and flat, saving you the headache of having to resurface the flange with a belt sander later.

3. Use High-Quality Hardware and Anti-Seize

Once your beautiful custom exhaust is finished, don''t ruin the installation by using cheap, Grade 5 hardware or old, rusty bolts. Because exhaust components undergo extreme heat cycles, standard nuts and bolts can "gall" or seize over time, making future maintenance a nightmare. Always use high-quality Grade 8 bolts or specialized copper-clad exhaust nuts. Furthermore, always apply a generous amount of high-temp nickel or copper anti-seize to the threads. This ensures that when you need to drop the exhaust for an oil change or engine service, the nuts come off smoothly without snapping a stud or stripping the threads on your custom-made headers.