420motorsport. Fuel Injection – Injectors, Fuel Rails & O-Rings

How the parts work together

Fuel injectors meter fuel to each cylinder, and fuel rails distribute fuel from the pump to the injectors. O-rings and seals seal between the injector, rail and intake. Connectors and adapters make it possible to fit injectors with a different design, both electrically and mechanically. Conversion kits combine several of these parts into one solution.

How to choose injectors and a fuel rail

Injector size must match your power target, fuel type and fuel pressure. Injectors that are too large can make idle and low load harder to control, while injectors that are too small can run out of capacity at high boost. Also look at:

Flow, e.g. 550 or 1000 cc/min, which BLOX Racing Eco-Fi Street Injectors are available in.

Fitment: O-ring diameter, injector length and whether an adapter is needed. The BLOX kits are available, for example, with adapters for the Honda B/D/H and K series.

Connector type, which must either match the car's wiring harness or requires an adapter harness.

Fuel rail capacity and connections, especially if a pressure regulator is also to be fitted. One example is the AMS Performance Alpha Fuel Rail Kit for the Nissan GT-R R35, which comes with a regulator.

New injectors typically require the engine management to be tuned. More flow often also requires a stronger fuel pump and regulator.

Installation and maintenance

During installation, the O-rings should be lightly lubricated and seated correctly so they do not get pinched or crack. A leaking O-ring can cause a fuel smell or a vacuum leak. For example, we stock O-rings from Injector Dynamics in 14 and 16 mm and injector seats from Radium Engineering in 25 and 30 mm for Nissan. It is a good idea to replace seals and O-rings every time the injectors have been removed. Other brands in the category include DeatschWerks, Grams Performance, Exergy and Industrial Injection.

Frequently asked questions

Does the engine management need tuning when I change injectors?

Typically yes, if the flow or injector characteristics change. The engine management needs the new injectors' data to calculate the correct amount of fuel. Otherwise the mixture can become too rich or too lean.

Can I reuse the old O-rings?

It is not recommended. Old O-rings can be hardened or deformed and cause leaks. New O-rings in the correct diameter are a simple safeguard whenever the injectors or fuel rail have been removed.

What does a fuel injection conversion kit include?

It depends on the specific kit. Check the product description for which parts are included and what you need to add yourself, e.g. a pump, regulator or engine management.

How do I know if an injector fits without an adapter?

Compare the O-ring diameter, injector length and connector type with the original injectors. If any of them differ, an adapter, an adapter harness or a different injector seat may be the solution, depending on the product.