Billet Aluminum Solex-to-Weber Carburetor Adapter Plates — Porsche 356 Super 90, SC & 912 (Pair)

Precision-machined billet aluminum carburetor adapter plates for converting Porsche 356 Super 90, SC, and 912 engines from the original Solex carburetors to Weber IDF or DCNF carburetors. Sold as a pair (one per side). Made by Washburn's Metal.

Why the Solex-to-Weber conversion is so common on 356s and 912s

The original Solex 40 PII-4 carburetors fitted to Porsche 356 Super 90, SC, and 912 engines are notoriously difficult to keep in tune. Parts availability is poor, rebuild specialists are rare, and even a properly-rebuilt set tends to drift out of sync within a few hundred miles. Many 356 and 912 owners have moved to Weber 40 IDF or 44 IDF carburetors over the years because they're easier to tune, more reliably available, and well-supported by the air-cooled performance community.

The challenge: the Weber bolt pattern doesn't match the Solex flange on the factory Porsche intake manifold. These adapter plates bridge that gap — Weber bolt pattern on top, Solex pattern on the bottom — letting you keep your original Porsche manifolds and add modern Weber carburetors without permanent modification.

Specifications

• Material: Billet aluminum
• Finish: Machined
• Configuration: Solex flange (bottom) to Weber flange (top)
• Sold as: Pair (one per carburetor)
• Manufacturer: Washburn's Metal

Fitment

• Porsche 356 Super 90 (1959–1963) — Solex 40 PII-4 carburetor manifold
• Porsche 356 SC (1964–1965) — Solex 40 PII-4 carburetor manifold
• Porsche 912 (1965–1969) — Solex 40 PII-4 carburetor manifold
• Other applications using the same Solex flange-to-Weber conversion

Important: These adapters work with the original Porsche Solex-pattern intake manifolds. If your manifolds have been replaced with Weber-direct manifolds, you don't need these adapters. Confirm your manifold flange pattern before ordering.

FAQ

Which Weber carburetor do these adapt to — IDF or DCNF?
The Weber flange pattern is the standard IDF/DCNF pattern used across the Weber sidedraft and downdraft line. Both 40 IDF and 44 IDF Webers bolt up. Contact us if you're running a less common Weber variant.

Do I need new linkage and air cleaners?
Yes. Solex-to-Weber conversion is a complete carburetion swap. You'll need Weber-specific linkage (typically a hex-bar style), Weber air cleaners, and matching jets/venturis for your engine's displacement and state of tune.

Will this reduce performance compared to properly-rebuilt Solex carbs?
No. A well-tuned Weber setup will match or exceed a properly-rebuilt Solex setup in driveability and reliability. The main downside is loss of originality — for a numbers-matching show car, keeping the Solex carbs is the more correct choice.

Are these reversible?
Yes. The conversion is fully reversible — your original Porsche manifolds aren't modified, just adapted. Save your original Solex carbs and you can go back to factory configuration anytime.

Do they include gaskets?
Contact us to confirm — gaskets vary by application and we typically supply or recommend the correct gasket sets based on your specific carburetor choice.

Will they fit a 356A or 356B with the smaller Solex 32 carbs?
No. These are sized for the larger 40 PII-4 manifolds used on Super 90, SC, and 912. The smaller-engine 356A/B uses a different manifold flange.