Radium Top Feed Injector Seats | Mazda 13B-RE/13B-REW/20B-REW (20-0444)

Sixteen-millimeter Mazda counterbores and 14mm modern injectors disagree by exactly one press-in seat.

The Radium Engineering Top Feed Injector Seats for Mazda Rotary Engines are the same machined aluminum injector seats used in Radium's fuel rails for Mazda/Eunos Cosmo and RX-7 rotary engines: required when converting the OEM 16mm injector seat counterbore to the 14mm standard of popular injector lower O-rings. They simply pop into the OEM injector bore, seal to the machined counterbore with the included Viton O-ring, and were designed specifically to be compatible with or without the OEM fuel injector diffusers installed. The green seats serve the irons (primary location) and the black seats serve the intake manifold (secondary location). Sold individually.

What You'll Feel

• Modern 14mm injectors seated correctly in 16mm rotary bores
• Boost-tight sealing at the injector base from the Viton O-ring interface
• Flexibility to run or delete the OEM diffusers without changing seats
• Spares on hand for rail services and 4-port manifold conversions needing extras

Features

• Machined aluminum injector seats, identical to those in Radium Mazda rotary fuel rails
• Converts the OEM 16mm injector counterbore to 14mm for popular injector lower O-rings
• Press-in installation; seals via included Viton O-ring
• Compatible with or without OEM fuel injector diffusers installed
• Green: primary location (irons); Black: secondary location (intake manifold)
• SOLD INDIVIDUALLY

The Details

These seats exist as a separate line item for two reasons: service, since a damaged or lost seat should not require a rail purchase, and expansion, since Radium's own secondary rail documentation notes that Elite Rotary Shop 4-port intake manifolds require 2 extra injector seats beyond the rail kit's included set, which is precisely this part. Installation follows the instructions' rhythm, cleaning the OEM ports, lubricating the seat O-rings, and firmly pushing the seats into place before the injectors and rail land on top. Suitable for 13B-RE, 13B-REW, and 20B-REW conversions. Count your ports and order accordingly, one seat per injector position.

Kit Includes

• 1x Machined aluminum top feed injector seat with Viton O-ring (specify color/location)

Applications

• Mazda 13B-RE, 13B-REW, and 20B-REW rotary engines
• Radium Mazda rotary top feed rail conversions; ERS 4-port manifolds need 2 extra
• Green = primary (irons); Black = secondary (intake manifold)