This is the V2.0 version of the .21 off-road Ultimate M4R tuned engine. The M4R V2.0 is a 4 port engine with tuned crankshaft and great and linear power at both low and high R.P.M. It boasts the most advanced technology and a top-level human capital that team up to further improve fuel mileage, overall performance and reliability.
The M4R has all what an engine needs to compete against other market leading engines, but at an affordable and very competitive price for a top-quality race engine.
The main changes from the previous version is that the V2.0 comes with a new cooling head design as well as the last evolution of carburettor which is even easier to tune and more stable at different RPM than the previous version.
It stands out the exclusive oversized cooling head 100% designed by Modelix R&D department also used on the M5 engines to keep the engine cooler and improve performance at high temperatures. It's been drilled and milled out to make it lighter and keep the overall center of gravity of the engine low. Besides this, the diameter of the central hole of the head where the glow plug fits has been reduced to better measure the temperature for those who use a temp gun .The reason to do this is to avoid that the temp gun touches the glow plug when measuring the temperature and have a more accurate temp reading.
The carburetor chosen for the M-4R engine is the plastic one from Novarossi. It is a "reverse" type with a sliding throttle valve. It provides high idle stability, more precise tuning and higher mid/top range power.
The exclusive 13mm turbo crankshaft has also been designed by the team and hand tuned and lightened to reduce rotation weight and is surprisingly strong and reliable thanks to our special steel and heat treatment.
The shape of the rear cover helps to optimize the crankcase filling and reduces dead space. The steel plate helps to reduce conrod-backplate friction and increases the life of the conrod and improves engine efficiency and performance.
This 4 transfer ports sleeve is the best option to provide high linear power at each RPM and low fuel consumption.
PISTON & CONROD
The R7 conrod is machined from a super light aluminum that has been checked ultrasonically. The unique shape of the R7 rod creates less turbulence inside the engine.
The material of the piston has been chosen for its excellent strength to weight properties. The flat shape of the top of the piston improves the efficiency of the engine.
Each piston is coupled with the sleeve to get the best compression and longevity. This operation is made by hand, one by one and checked by a specific precise measurement tool.
TURBO PLUG UNDERHEAD BUTTON
The combustion chamber has a special shape to increase the performance during combustion. The sealing o-ring avoids vibrations and also protects the assembled sleeve/crankase from external dust. This head button is for Turbo plugs, not Standard plugs. It's been market with an arrow to make sure you always assemble it correctly.
The front bearing has a double rubber shield protection against dust. The main bearing is calibrated and assembled by hand and its tolerance is twice checked by a specific measurement machine.
Displacement: 3,49 cc
R.P.M. (max power): 34.500
Practical Range: 7.000-36.500
Bore x Stroke: 16,42x16,42
Sleeve: 4 ports
Rear Ball Bearing: steel
Front Ball Bearing: steel
Crankshaft: 13 mm - turbo - tuned
Carburetor: plastic - 9 mm - reverse
Glowplug: Turbo (C6TGC)
Exhaust Position: rear
Fuel type: 25% nitro. Recommended fuel Nitrolux.