🏁 The REDS Racing 321 Estremo Worlds Edition is a Nitro 3.5 cm³ engine and resonator set specially developed for 1/8 off-road racing. Based on the 321 Estremo platform used during the 2026 racing season, this Worlds Edition combines a high-performance performance engine with a specialized cooling cylinder head and the REDS 2143 X-ONE Worlds Edition resonator with OXD surface treatment. The entire assembly was designed to promote consistent engine performance, particularly during extended races and in high-temperature conditions.
- Brand: REDS Racing
- Model: 321 Estremo Worlds Edition
- Part Number: REDCOBU0040
- Type: Nitro Nitro 2-stroke engine
- Displacement: 3.5 cm³
- Category: Buggy and Truggy 1/8 combustion engines
- Version: Worlds Edition 2026
- Bore: 16.4 mm
- Stroke: 16.4 mm
- Valve train: 3 intake ports and 1 exhaust port
- Engine weight: 345 g
- Cylinder head: Worlds Edition, optimized for Nitro management
- Crankshaft: DLC coating
- Balancing: 2 tungsten weights
Bearings
- Front bearing: 7 x 19 x 6 mm, sealed design
- Rear bearing: 14 x 25.4 x 6 mm
- Rear Bearing Type: 9-ball ceramic
Fuel system
- Carburetor: OS 21J
- System: XFlow Venturi
- Included venturi: 7 mm
- Optional venturis: 6 mm and 8 mm
Resonator
- Model: REDS 2143 X-ONE Worlds Edition
- Series: X Line
- Treatment: OXD
- Function: Exhaust gas and temperature management
- Benefit: Protection against wear and damage caused by high temperatures
Recommended settings and consumables
- Recommended clutch: REDS TETRA-X
- Recommended clutch configuration: 4 aluminum weights, Medium setting
- Recommended spark plug: REDS TS3
- Recommended fuel: 16–30% nitromethane
- Recommended oil content: 8 to 10%
The REDS 321 Estremo Worlds Edition features a cooling cylinder head specially developed for this version.
It was designed to improve engine temperature management, particularly during long races or when outside temperatures are high.
A more stable operating temperature offers several advantages:
- More consistent fuel delivery during races.
- Reduced temperature fluctuations during intensive use.
- More consistent engine performance throughout the race.
- Better temperature control under demanding racing conditions.
This design aims to maintain smooth engine operation when thermal stresses become significant.
This kit includes the REDS 2143 X-ONE X Line Worlds Edition resonator, featuring an OXD surface treatment.
This treatment was developed to improve the resonator’s resistance to the stresses encountered in competition.
In particular, it:
- Protect the resonator’s surface from wear.
- Minimize damage caused by high temperatures.
- Improve resistance to intensive use.
- Contribute to exhaust gas management Nitro.
The combination of the 321 Estremo engine and the 2143 X-ONE Worlds Edition resonator is designed to meet the demands of 1/8 off-road racing.
- 1 Nitro REDS Racing 321 Estremo Worlds Edition 3.5 cm³ engine
- 1 resonator REDS 2143 X-ONE Worlds Edition with OXD treatment
- 1 OS 21J carburetor with XFlow Venturi system
- 1 7 mm venturi
This set is designed for 1/8-scale off-road RC cars with internal combustion engines, including:
- Buggy 1/8 Nitro
- Truggy 1/8 Nitro
Be sure to check that the engine mount and exhaust system are compatible with the chassis you are using.
The REDS Racing 321 Estremo Worlds Edition with 2143 OXD resonator is designed for buggy and truggy 1/8 scale nitro models who compete and are looking for an engine capable of maintaining smooth operation under demanding conditions.
With its Worlds Edition cylinder head, OXD-treated resonator, OS 21J XFlow carburetor, and competition-grade mechanical components, it provides a complete engine/resonator package for preparing a vehicle for off-road racing.
