10 Best Radium Engineering Rail 2026

⚡ Quick Verdict

📋 How We Evaluated

Each rail gets evaluated for build quality, including CNC machining and aluminum finish, plus plumbing usability like AN ORB port threads and sealing surfaces. Performance focuses on fuel delivery consistency and how well the rail supports higher-flow injectors and tuning.

Value considers what the kit includes, while Amazon rating signals and Prime availability indicate buyer confidence and shipping reliability. User suitability emphasizes fitment confidence by application and how easily installers can integrate existing fuel system components.

Port Style	8AN ORB (3/4-16 female)
Number of Ports	3
Kit Contents	Fuel rail and mounting hardware
Compatibility	1994-2005 Mazda Miata/MX-5 (with stated fitment notes)

What We Found

Radium’s fuel rail for 1994-2005 Mazda Miata/MX-5 focuses on flexible custom plumbing. The listing states that all three ports use machined 8AN ORB (3/4-16 female) threads, which supports reliable sealing with ORB style fittings.

The kit includes the fuel rail and mounting hardware only, which suits builders who already have hoses, regulators, and fittings chosen. This design suits setups where the factory routing no longer matches a swapped or modified fuel system layout.

The standout is the consistent port machining across three ports, which makes part selection simpler when building a tidy AN-based fuel line plan. The listing also references fitment breadth, though exact year coverage details should be confirmed for a specific chassis and fuel rail configuration.

Who It’s For

This rail best serves fabricators and tuners building a complete AN fuel system for Miata or MX-5 projects. It fits well when injector line routing, regulator placement, or return line strategies require custom hose lengths and adapters.

The included mounting hardware helps reduce effort compared with rails sold without installation components. It also suits owners upgrading from worn factory fuel rail components who want ORB sealing stability.

Because the kit excludes additional plumbing parts, buyers should plan hoses, fittings, and a regulator compatible with their chosen AN sizes.

Part Number	20-0359
Construction	6061 Aluminum
Finish	Black Anodized
Manufacturing	CNC Machined

What We Found

The Radium 20-0359 top-feed fuel rail conversion kit for Nissan SR20DET (S14/S15) combines manufacturing clarity with strong materials. The listing calls out CNC machining and 6061 aluminum construction, plus a black anodized finish for corrosion resistance and a clean, stealthy look in the engine bay.

As a conversion kit, it aligns with projects moving to top-feed injector routing, often improving packaging and reducing constraint from factory underfeed designs. The product naming includes the exact Radium part number, which helps verify selection when multiple SR20 variants exist.

The listing does not include port size or included hardware details, but the rail’s stated build quality fundamentals remain a clear advantage. In short, machining quality plus 6061 aluminum and anodizing make this rail feel purpose-built rather than generic.

Who It’s For

This kit works best for SR20DET S14 and S15 owners planning a top-feed conversion for tuning and injector upgrades. It suits street and track builds where consistent fuel pressure delivery matters during sustained pulls.

The 6061 aluminum construction and anodized finish appeal to owners who care about long-term durability and clean installation aesthetics. Buyers should verify their regulator and fitting plan since port threading and included components are not specified here.

For anyone doing a conversion, the exact part number labeling helps reduce the risk of buying the wrong variant.

OEM Equivalent Part Number	20-0567-02
Part Number	20-0567-02
Compatibility	02-14 Subaru WRX/STI (top feed upgrade)
Fuel System Type	Top feed

What We Found

This Radium Engineering top-feed fuel rail upgrade targets 2002-2014 Subaru WRX and STI applications, using OEM equivalent part number 20-0567-02. The product centers on top-feed conversion compatibility, which helps maintain consistent injector feed routing during performance builds.

Radium’s typical approach emphasizes precise machining so AN-compatible fittings can seat cleanly and seal reliably. The listing explicitly calls out the specific fitment range and part numbers, which simplifies selection for WRX/STI owners.

Build quality expectations align with Radium’s aluminum rail designs, but this listing does not provide visible material or anodizing details. Overall, the standout trait here is model-specific targeting via the exact part reference, which reduces install guesswork for supported Subarus.

Who It’s For

This rail fits best for WRX/STI owners who want a straightforward upgrade that stays aligned with Radium’s 20-0567-02 specification. It suits street builds aiming for stable fuel pressure with tuning-ready hardware integration. It also works for track-focused setups where top-feed routing improves system organization and reduces packaging conflicts.

Buyers should confirm their intended fitting size strategy since this listing does not state port thread standards. For those doing a full fuel system refresh, the application-specific match helps keep downtime low.

Compatibility	Mazda 13B-REW Secondary (top feed conversion)
Conversion Type	Top feed conversion
Brand Part Detail	Radium Engineering
Intended Use	Fuel routing update for rotary secondary

What We Found

Radium’s top-feed conversion fuel rail targets a specific Mazda application: the 13B-REW secondary. The listing focuses on conversion functionality rather than general-purpose fitment, which typically means the rail adapts fuel delivery location to top-feed style requirements for rotary builds. However, the listing provides minimal technical detail beyond the stated compatibility.

Build quality cannot be confirmed from materials, anodizing, or machining specifics because no such details appear in the provided features. Still, the product’s naming indicates Radium’s intent to address a known swap and conversion use case, which often matters more than generic universal rails.

The rail’s key value lies in application-specific conversion for the 13B-REW secondary, reducing the chance of misfit when completing a top-feed conversion plan.

Who It’s For

This rail fits rotary builders who specifically run a Mazda 13B-REW secondary and want a top-feed conversion. It suits projects where fuel routing and injector packaging require moving toward top-feed configuration for better installation clarity. The conversion focus helps owners who already use supporting components tuned for top-feed delivery behavior.

Because the listing lacks port thread and kit contents information, planning becomes the buyer’s responsibility. Confirm fitting sizes, seals, and mounting strategy before purchase to avoid delays during fabrication or tuning.

Compatibility	2013+ Scion FR-S / Subaru BRZ / Toyota 86
Kit Type	Fuel rail kit
Brand	Radium Engineering
Details Provided	Compatibility only

What We Found

Radium’s fuel rail kit compatible with 2013+ Scion FR-S, Subaru BRZ, and Toyota 86 targets a modern platform with common performance upgrades. The listing provides only compatibility and no additional feature details, so material, finish, and port threading remain unspecified.

That gap matters because these cars often use established fuel system components where correct AN or OEM sealing methods prevent leaks and pressure drop.

The product name positions it as a rail kit, which implies it may include more than the bare rail, yet the listing does not confirm included items. Performance benefits depend on how the rail supports higher-flow injection and stable pressure under load.

Despite the limited data, the application grouping is useful, because buyers can target compatibility for the specific Subaru/Toyota twins and FR-S platform.

Who It’s For

This kit fits drivers and tuners upgrading 2013+ FR-S, BRZ, or 86 fuel systems for track days or horsepower-focused builds. It suits buyers who want a platform-specific option that aligns with a common upgrade path.

If a complete fuel system plan already exists, the compatibility label reduces the risk of selecting an incorrect rail. However, the lack of stated port sizes and contents makes this less suitable for custom builders who need detailed integration guidance.

Confirmation of fittings, mounting hardware, and return/pressure strategy remains essential before ordering.

Part Number	20-0545
Compatibility	GM LSA/LS9
Kit Type	Fuel rail plumbing kit
Brand	Radium Engineering

What We Found

Radium’s fuel rail plumbing kit for GM LSA/LS9 appears as product 20-0545 in the listing. The name indicates it supports plumbing for supercharged GM platforms rather than a universal rail body upgrade.

The provided content does not describe machining, material, finish, or specific fitting types, so sealing and compatibility planning must come from outside documentation. Still, the strongest value here is the explicit application target: GM LSA/LS9.

Buyers using these platforms often face complex routing constraints for feed and return lines, and a dedicated plumbing kit helps reduce guesswork around hose routing and component selection. The listing’s lack of technical features also prevents judging whether the kit includes adapters, fittings, or only rail-related plumbing components.

As presented, the product functions as an application-labeled plumbing option anchored by Radium 20-0545.

Who It’s For

This kit suits GM LSA and LS9 owners who need assistance with fuel rail plumbing integration. It fits performance builds where routing and fitting selection must remain consistent with a known Radium solution. The kit also helps reduce installation time when shop documentation already references 20-0545.

Because the listing does not confirm included fittings or port standards, it suits buyers who can verify their current fuel system components. If hoses, AN adapters, and regulator fittings already exist, this plumbing kit can streamline final connections.

Part Number	20-0277
Compatibility	RB25DET
Fuel System Type	Top feed
Brand	Radium Engineering

What We Found

Radium’s 20-0277 top feed fuel rail kit focuses on the RB25DET application. The listing provides a single explicit product identifier, RADIUM 20-0277, plus the top-feed function in the title.

No further details appear about construction, anodizing, or port threading, so sealing and plumbing compatibility cannot be evaluated from the provided features. For RB25DET builds, top-feed rails can improve injector feed routing and packaging, especially when upgrading fuel systems for higher power.

Still, the performance outcome depends on port thread standards, included hardware, and how the rail integrates with regulators and return lines. Because the listing omits kit contents, buyers must verify whether mounting hardware and necessary adapters are included.

In summary, the standout remains the top-feed intent and exact Radium part reference, but the text lacks the technical data needed for deeper assessment.

Who It’s For

This rail targets RB25DET owners seeking top-feed fuel delivery configuration for tuned builds. It fits street and track projects where injector routing and engine-bay packaging matter. It also suits installers who already plan fitting standards and have matching regulators and AN lines selected.

The listing’s minimal details make it less ideal for first-time top-feed conversions where port threading and sealing approach drive most decisions. Before purchase, confirm the exact sealing interface and whether the kit includes mounting hardware and adapters for the intended fuel system layout.

Compatibility	Honda B-Series
Part Reference	20-0370-02
Brand	Radium Engineering
Details Provided	Fitment only

What We Found

Radium’s fuel rail labeled for Honda B-Series uses a part reference of 20-0370-02, but the provided listing lacks further specifications. The feature set shows no stated port threading, material, or finish, which prevents judging sealing compatibility or durability expectations from this text alone.

For buyers, the key value comes from the explicit compatibility label “FITS Honda B-Series 20-0370-02,” which can help confirm selection when multiple B-series variations exist. Performance implications depend on how the rail supports injector and return strategies, yet that information is absent here.

Build quality cannot be confirmed without listed CNC or anodizing details. Still, the application designation acts as a helpful anchor for installers who cross-check parts to their engine bay layout and fuel routing needs.

Who It’s For

This rail suits Honda B-Series swap and rebuild projects that match the 20-0370-02 application reference. It fits when a known Radium B-series rail selection reduces trial-and-error during planning. It also suits owners who already know the required port sizes from their existing AN fittings and regulator.

However, the listing provides too little technical data to guide custom integration, so confirmation with the manufacturer or documentation is important. Buyers should confirm whether the system uses top-feed or the intended rail routing strategy before purchase.

Part Number	20-0230-02
Compatibility	Honda K-Series
Brand	Radium Engineering
Details Provided	No features listed

What We Found

Radium’s 20-0230-02 fuel rail for Honda K-Series appears in the listing with no additional technical feature details. The only usable specifics are the part number and the K-series application categorization, which means the rail’s port style, materials, and included hardware cannot be assessed from the provided content.

That omission matters because fuel rails rely on sealing integrity and correct thread standards for reliable pressure delivery. Without stated port threading, builders may face mismatches with their AN fittings, regulator, or return components. Performance characteristics and build confidence also remain unknown based on the text.

For some buyers, the part number still reduces risk by enabling cross-checking with existing documentation or vehicle-specific compatibility charts.

Who It’s For

This rail targets Honda K-Series owners who already know the correct Radium part number for their engine and fuel system plan. It suits replacement or upgrade projects where compatibility is already confirmed by documentation or shop experience.

It also fits builders who prefer ordering once the port sizing is predetermined by their existing hardware. However, the lack of listed details makes it less suitable for first-time installers who need guidance. Before purchase, confirm port threading, top-feed versus return style, and whether mounting hardware or fittings come included.

Compatibility	2013+ Scion FR-S / Subaru BRZ / Toyota 86
Kit Type	Fuel rail plumbing kit
Brand	Radium Engineering
Details Provided	Compatibility only

What We Found

Radium’s fuel rail plumbing kit listing references compatibility with 2013+ Scion FR-S, Subaru BRZ, and Toyota 86. The product name indicates plumbing-focused support, which typically means it provides components needed to connect fuel rail feed and return lines cleanly for the specified platform.

However, the provided features do not include part numbers, materials, finish, or fitting thread standards. Without that information, buyers cannot confirm how the kit interfaces with existing AN fittings, fuel hoses, regulators, or return components.

Performance implications remain indirect, since plumbing quality affects leak resistance and pressure stability, but those details are absent here. Still, the explicit platform compatibility can reduce selection mistakes for owners who already know their exact fuel system architecture and simply need the correct plumbing set.

Who It’s For

This kit fits builders who already have a rail and regulator plan for 2013+ FR-S, BRZ, or 86 and need plumbing components to finish connections. It suits shops aiming for consistent routing and reduced trial-and-error during installation.

Because the listing lacks fitting standards and included items, it fits best for buyers who can verify compatibility against their existing fuel lines and adapters. It also helps when a correct, platform-specific plumbing bundle already matches the rest of the upgraded system.

Confirm included hardware and thread interface before purchase to avoid delays.

What to Look For Before Buying

When choosing a Radium Engineering rail, first confirm engine compatibility and whether the setup requires top-feed conversion or standard routing. Next, verify port threading and sealing style, especially ORB vs other interfaces. Consider what the kit includes: mounting hardware only, or full plumbing support.

Finally, check build materials and finishes for corrosion resistance and long-term durability.

Check Verify exact engine fitment and feed style

Confirm compatibility with the specific engine code and year range, not just the brand name. Identify whether the build calls for top-feed or a conversion kit, since injector routing changes with each style. Match your existing mounting points and regulator location to the rail’s intended layout.

Use part numbers in listings to cross-check with build documentation.

Value Compare kit contents against the rest of the fuel system

Some kits include only the rail and mounting hardware, which means fittings, hoses, and regulator accessories require separate purchases. Plumbing kits may include adapters or only routing components, so read the included-hardware list carefully. Value improves when kit contents remove the most expensive unknowns, like ORB-compatible fittings.

Plan the full feed/return line layout before buying.

Rating Use rating and Prime signals, then validate fitment

When available, higher Amazon ratings and Prime availability often correlate with easier installation and fewer missing-parts issues. For listings with no rating data, rely more heavily on part numbers and published port standards. Confirm returns and compatibility notes from the seller to reduce risk.

Even well-reviewed rails require confirmation against thread and sealing interfaces.

Verify Confirm port threading and sealing interface

Port threading standards determine which AN fittings, adapters, and regulators fit correctly. ORB threads typically require ORB-style sealing, so avoid mixing incompatible sealing types. Check both feed and return ports count, and ensure each line uses the intended orientation.

When details are missing, request specs from the seller or manufacturer before checkout.

Frequently Asked Questions

What does “top feed” mean for fuel rail upgrades?

Top feed refers to routing the fuel rail so injectors receive fuel from above, usually improving packaging and enabling cleaner builds. Many conversions also help align injector angles and reduce hose strain. It can affect regulator and return line layout, so compatibility depends on the conversion kit.

Confirm top-feed intent before choosing fittings and injector plumbing.

Why do ORB threaded ports matter when using AN fittings?

ORB threads use a sealing cone style that matches ORB fittings for consistent leak-resistant joints. Correct ORB compatibility reduces the risk of pressure leaks and seepage under boost. If fittings use the wrong seal type, builders may experience leaks or unstable pressure.

Always match ORB (or the specified sealing interface) with compatible AN adapters.

Do Radium rail listings always include mounting hardware and fittings?

Not always. Some listings specify the kit includes the rail and mounting hardware only, which means AN hoses, regulators, and fittings require separate selection. Other listings describe a plumbing kit, which may still omit critical adapters. Review kit contents carefully and verify what is included in the box before ordering.

How can compatibility be confirmed for Subaru and Nissan applications?

Use the exact part number and OEM equivalent part reference included in the listing to confirm fitment. Cross-check with vehicle year, chassis code, and any fuel system conversion documentation. For swaps, verify that the rail’s mounting layout matches the intake manifold and injector configuration.

When port threading details are missing, confirm with the manufacturer before purchasing.

What should be checked before installation to avoid fuel system problems?

Confirm port thread standards, sealing style, and fitting sizes before tightening connections. Inspect all hoses for correct length and routing clearance to prevent abrasion under vibration. Plan regulator and return line connections to avoid improper pressure control. After installation, leak-test under pressure and recheck hardware after initial heat cycles.

🎯 Final Verdict

For most SR20DET top-feed conversion shoppers, Radium 20-0359 delivers the clearest build quality with CNC machining, 6061 aluminum, and black anodizing. That combination makes integration smoother and durability stronger than listings that omit technical details.

For a flexible custom-plumbing alternative, the 8AN ORB three-port Miata/MX-5 rail stands out by standardizing ORB sealing threads across all ports. Compare your engine fitment and port thread requirements, then select the rail that matches your fitting ecosystem.