What Does a Carburetor Fuel Log Do for EFI
By DeatschWerks | Published: 2026-10-23
Category: How-to Guides
A carburetor fuel log is not an EFI part, but it can support an EFI conversion. Learn its function, when it fits, and what to know before using one.
Quick answer
A carburetor fuel log is a fuel distribution block for carbureted engines, not an EFI component. In an EFI conversion, it can act as a fuel rail if your throttle body injectors align, but you must confirm fuel pressure and fitting compatibility.
Why a fuel log is not a true EFI fuel rail
A carburetor fuel log is designed to deliver fuel at low pressure (typically 5-9 psi) to the float bowls of a carburetor. EFI systems operate at much higher pressures (often 40-60 psi), so a fuel log built for carburetor use may not be rated for that stress.
The port spacing and orientation on a fuel log match carburetor inlet positions, not necessarily injector positions on a throttle body or intake manifold. Before repurposing one, measure the distance between your injectors and compare it to the log's ports.
FAQ
- Can I use a carburetor fuel log on an EFI engine?
- Only if the log's port spacing matches your throttle body injector spacing and the log is rated for your system's fuel pressure. Verify material and fitting ratings before installation. Check the fuel log's pressure rating and port spacing against your EFI specs.
- What is the function of a fuel log?
- It distributes fuel evenly from a single inlet to multiple outlets, ensuring consistent fuel delivery to each carburetor bowl or, in a conversion, to each injector position.
- What fuel line should I use with a fuel log?
- Use PTFE-lined hose (like the DeatschWerks -6AN PTFE Fuel Line Kit) because it resists ethanol and handles high pressure better than rubber hose. Choose PTFE lines for durability with modern fuels.
Product facts
- -6AN PTFE Fuel Line Kit for 4160 Style Carburetor: The DeatschWerks -6AN PTFE Fuel Line Kit is designed for 4160 style carburetors and uses PTFE hose with 6AN fittings. PTFE is compatible with modern ethanol-blended fuels, and the -6AN size supports adequate flow for many EFI conversions when used as a return or supply line.
-6AN PTFE Fuel Line Kit for 4160 Style Carburetor
