Robert Batlle & Ultimate Racing: A Legendary Partnership That Keeps Making History

Robert Batlle, one of the most iconic names in the world of RC, is also the longest-standing driver on the Ultimate Racing team. As he puts it:
“Over 25 years working side by side, pushing the limits and achieving major victories like the 2012 World Championship, three European titles, and many other prestigious international wins.”
And now, in 2025… we’re raising the bar once again!

Introducing the new Ultimate R36 engine, the result of years of development between Robert and our technical team. This engine represents the perfect balance: smooth, easy to drive, and with fuel efficiency that will blow your mind.
Robert says it best:

“I’m truly proud of this project. The R36 is super smooth and linear, and with the Supersonic 2141 pipe, the on-track feeling is just insane. And the fuel efficiency? Out of this world!”
The Ultimate Combo?

The new R36 comes paired with the Supersonic 2141 exhaust with ceramic treatment, our great FlowMax venturi, our renowned AIRMAX air filter, and a custom exhaust mount — all designed to squeeze out maximum performance.

ENGINE
Manufactured by the prestigious O.S. Engines, the R36 is based on the square-stroke Speed B21, evolving from the previous MXS with key upgrades: new intake and exhaust timing, a redesigned backplate, and an optimized crankcase.
It features a sealed combustion chamber with an O-ring for flawless sealing and maximum linearity. And yes — the FlowMax venturi is included, making this a truly elite package.
The result?
A power curve that’s smooth yet explosive when needed, delivering responsive and consistent performance through every turn — and one of the best idles on the market.

COOLING HEAD
The 8-fin head is the same proven design found on our current engines, but with a unique look that makes it stand out. With a low center of gravity and an airflow-optimized shape that directs cooling straight to the glow plug, it ensures more stable carb tuning and idle — even under extreme conditions.

CARBURETOR
The O.S. 21 J3 carb has been refined with a custom high-speed needle holder featuring head-style fins to help maintain a cooler, more stable temperature — boosting both performance and efficiency. Unlike the original OS carburetor, its high-speed needle holder was redesigned for a better refrigeration of the fuel flow into the carburetor, lowering the temp of the carb, and consequently it is more stable with a great idle stability, improves fuel mileage and overall engine performance.
The carb comes with the Dust Cover Ring from Ultimate Racing. This ring has been designed to guarantee the best sealing of the carburetor.
Besides this, the uniball joint of the carb slide was also modified with two stoppers instead of one. With this new modified design, you can easier adjust the angle of the uniball joint without having to disassemble the engine.
For those who love to fine-tune, this carb delivers ultra-precise adjustments, ideal for expert drivers.

BACKPLATE
CNC-machined from Swiss 7075-T6 aluminum, the new backplate features larger cutouts to improve fuel flow and boost power.
Its smart design allows for safe removal — even with the piston at bottom dead center — without any special tools or risk of damage.

CRANKSHAFT
Coated with DLC and equipped with two tungsten counterweights, the crankshaft improves rotational inertia, delivering smoother mid-range response and more progressive throttle feel.

BEARINGS
At the rear, an original O.S. ceramic bearing. At the front, a steel double-sealed Ultimate Racing bearing.
This combo ensures exceptional smoothness and long-lasting durability.

VENTURI
The engine includes two FlowMax venturis (6.0 and 6.5 mm) with a new design: longer and with a wider base, they fit perfectly into the carb, optimizing internal flow.
The result?
More power with smaller venturis, meaning better fuel mileage without sacrificing performance.

SLEEVE & PISTON
Building on the MXS platform, we’ve redesigned the engine internals with new porting and timing to unlock more power — without hurting fuel consumption.
The 3-transfer intake and single exhaust port layout delivers smooth, efficient, and highly usable power. Both the sleeve and piston are made from high-grade aluminum bar stock for maximum longevity.

CRANKCASE
The crankcase has been reworked internally to improve fuel flow and boost performance. Laser-engraved with Robert’s signature “36” and the limited edition number, it’s as exclusive as it is functional.

EXHAUST
The new Supersonic 2141 pipe delivers ultra-smooth throttle response, a distinctive sound, and a ceramic finish that looks great and holds up over time — without compromising performance.
Ready to Take Your RC Car to the Next Level?
With the Ultimate R36 + Supersonic 2141 combo, you get it all:
Power, reliability, style, efficiency… and most importantly: a champion’s DNA.

TECHNICAL SPECIFICATIONS

• Displacement: 3,49 cc
• Power Output: 2.65 PS/2.61 hp @ 34,000 rpm
• Practical Range RPM: 4,000 - 42,000 rpm
• Bore x Stroke: 16,40x16,40mm
• Sleeve: 3 + 1 ports
• Rear Ball Bearing: ceramic
• Front Ball Bearing: steel
• Crankshaft: 14 mm
• Carburetor: 21 J3
• Glow plug: P3 Turbo
• Exhaust Position: rear
• Fuel type: Recommended Nitrolux Energy3 16%-25%.