Radium Primary Top Feed Conversion Fuel Rail - Mazda Cosmo JC (20B-REW)
Radium Primary Top Feed Conversion Fuel Rail - Mazda Cosmo JC (20B-REW)
SKU: SKU: 20-1120
More info
Radium 20B-REW Primary Fuel Rail — Mazda/Eunos Cosmo JC (20-1120)
Note: This rail replaces the discontinued Radium 20-0464. Radium's new part number for this product is 20-1120.
The Radium Engineering high flow primary fuel rail is for the 20B-REW rotary engine originally found in the 1990-1995 Mazda/Eunos Cosmo. The aluminium fuel rail is anodised black for compatibility with all popular fuel types including E85. Manufactured with a large internal bore, the fuel rail can support all necessary engine power requirements.
Thermal insulating spacers and washers are included with stainless steel hardware to prevent thermal energy from conducting heat into the fuel. The included 14mm lower injector seats were designed specifically to be compatible with or without the OEM diffusers in place. They feature FKM O-rings making them suitable for boosted applications.
Ports & Fittings
The fuel rail ports are tapped for 8AN ORB, with three ports in total. The extra centre port allows additional fuel system accessories such as the OEM fuel temperature sensor (using Radium 14-0421), a pressure transducer, Radium fuel pulse damper, etc.
- 8AN ORB adapter fittings sold separately — appropriate fittings must be selected based on the specific application
- Ample space around the fuel rail port(s) is necessary for larger accessories such as fuel pressure regulators, fuel pressure gauges, and fuel pulse dampers
- Use the dimensional drawings on the relevant product pages as a reference guide to verify clearance
Fuel Injector Requirements
Universal fuel injectors with the following dimensions are required when installing this fuel rail. The injectors must have 34mm height with 14mm O-rings (fits 14mm bore): 34.3mm (±1) top-to-bottom O-ring spacing and 42.5mm (±1) overall length, per Radium's dimensional drawing.
Many injector manufacturers will have applications with these dimensions. Here are a few examples of applicable injector part numbers from Injector Dynamics:
- Injector Dynamics 1050-XDS — 1050.34.14.14
- Injector Dynamics 1300-XDS — 1300.34.14.14
- Injector Dynamics 1700-XDS — 1700.34.14.14
- Injector Dynamics 2600-XDS — 2600.34.14.14
Fuel injectors are NOT included and must be purchased elsewhere.
Included
- Anodised billet aluminium fuel rail
- Anodised billet aluminium injector seats
- Thermal spacers
- Mounting hardware
Specifications
| Part Number | 20-1120 (replaces 20-0464) |
| Application | Mazda/Eunos Cosmo JC — 20B-REW (1990-1995) |
| Configuration | Primary fuel rail, top feed conversion |
| Ports | 3 × 8AN ORB |
| Construction | Billet aluminium, large internal bore |
| Finish | Anodised black |
| Injector Seats | 14mm lower seats — compatible with or without OEM diffusers |
| O-Rings | FKM — suitable for boosted applications |
| Fuel Compatibility | Gasoline, E85, and all popular fuel types |
| Mounting | Thermal insulating spacers with stainless steel hardware |
Why Radium Engineering?
- ✅ Manufactured in the USA to motorsport-grade tolerances
- ✅ CNC-machined billet aluminium components built for performance and longevity
- ✅ Real-world high-power build credibility trusted by tuners and race teams worldwide
- ✅ Bolt-on design — no cutting, drilling, or fabrication required
- ✅ Compatible with E85, pump petrol, methanol, and all popular fuel types
Fast shipping available throughout Australia. Lead times may vary — contact us for current availability.
