Welded Race Fan, Fits VW Upright Shrouds, 37mm Wide

OVERVIEW

When you are pushing your air-cooled Volkswagen engine to the limit, the last thing you want to worry about is a catastrophic cooling failure. Standard factory fans are manufactured using a crimped design that was never intended to withstand the extreme centrifugal forces generated by high-performance, high-revving engines. At high RPMs, these stock fins can actually flatten out or, worse, detach entirely, turning your cooling shroud into a blender and causing immediate engine overheating. The EMPI Welded Race Fan is the definitive solution for serious builders who demand reliability. By TIG welding every single fin to the inner and outer rings, this fan eliminates the structural weaknesses of the original design, ensuring that the blades stay exactly where they belong, even when you are winding out that stroker motor on the track or the dunes.

Beyond its incredible structural integrity, this 37mm wide race fan is precision balanced to minimize vibration, which is critical for the longevity of your alternator or generator bearings. A vibrating fan doesn''t just make noise; it creates harmonic resonance that can lead to premature failure of the charging system and even the engine case itself. This fan is designed specifically for "doghouse" style upright shrouds, providing the maximum air volume necessary to keep your cylinder heads cool under heavy load. Whether you are building a weekend warrior, a dedicated drag racer, or a high-performance street sleeper, upgrading to a welded and balanced fan is cheap insurance against the "grenade" effect that often haunts high-RPM Type 1 engines. Don''t let a stamped-metal factory part be the weak link in your performance build.

FITMENT

This 37mm wide welded race fan is designed for Type 1 based upright engines utilizing the wider "doghouse" style cooling shroud. It is a direct fit for the following applications:

• Volkswagen Beetle: 1971-1977 (Including Super Beetle)
• Volkswagen Karmann Ghia: 1971-1974
• Volkswagen Bus (Type 2): 1971 (1600cc Dual Port models)
• Volkswagen Thing (Type 181): 1973-1974
• Custom Builds: Any air-cooled VW engine retrofitted with a 1971-later "Doghouse" style upright fan shroud.

SPECS

• Product Name: EMPI Welded Race Fan
• Part Number: 4586-10
• Width: 37mm (High-capacity "Doghouse" width)
• Construction: Heavy-duty steel with TIG welded fins
• Balance: Precision dynamic balancing for high-RPM stability
• Compatibility: Fits standard VW alternator and generator shafts
• Finish: Industrial-grade coating for corrosion resistance
• Quantity: Sold Each

PRO TIPS

1. Verify Shroud Clearance and Alignment

Before you tighten the 36mm fan nut, always rotate the fan by hand within the shroud to check for any rubbing or interference. Performance shrouds, especially aftermarket chrome versions, can sometimes have slight variances in their stamping. If you hear a "tink-tink" sound, you may need to shim the fan hub or slightly adjust the shroud positioning. Even a tiny amount of contact at low speeds can lead to significant heat and friction damage at 5,000 RPM. Ensure the fan is centered perfectly to maximize airflow efficiency and prevent mechanical drag.

2. Inspect Your Fan Hub and Woodruf Key

A welded fan is only as strong as the hub it sits on. When installing this race fan, take a close look at your fan hub and the woodruff key on the alternator or generator shaft. If the keyway is wallowed out or the hub shows signs of cracking, replace them immediately. A high-performance fan creates significant torque upon acceleration, and any play in the mounting hardware will eventually shear the key or strip the hub. Always use a high-quality fan nut and torque it to the factory specification of 40-43 ft-lbs to ensure it stays locked in place during high-revving sessions.

3. The Importance of the 37mm Width

It is crucial to remember that this is a 37mm wide fan, which is significantly wider than the early 1200cc-1500cc fans (which were roughly 31mm). If you try to force this fan into an early, non-doghouse shroud, it will hit the back of the shroud and fail to spin. Conversely, if you use an early thin fan in a late-model doghouse shroud, you will lose a massive amount of cooling pressure because the air will bypass the fins. Always match your fan width to your shroud type. For maximum cooling on a performance engine, the combination of this 37mm welded fan and a genuine doghouse shroud with an external oil cooler is the gold standard.