OPS/Radical 621T. Take advantage of the recent drop in the Euro. Brand new 2010 Radical/OPS factory modified engines. Brand new Cinderella cooling head design provides enhanced cooling and aerodynamics. Enhanced carburetion provides better fuel economy. Same internal engine parts that took 2nd and 4th at the Brazilian NATS 2009. I'm telling you guys with the recent drop in the Euro it is time to give the Radical line a try. We guarantee you will love our OPS engines. Everything seen in the picture is what you get! This is the Off-Road 621T HIGH TORQUE version of the Radical 621 line of OPS engines. Note the tear drop porting on the sleeve which is differant to that of the 621P power on-road engine. Comes with Venturi carburetor 6,7,8mm inserts. Manufactured by OPS in Italy. Engine Characteristics: Tremendous Bottom end with super Mid-High end power. Here are some specs: Displacement: 3.5cc (.21 ci ) Horse Power: rated 3.07 hp RPM: 35,000. This Italian stallion is a true work horse in the realm of off-road 1/8th scale competition engines. You will be amazed by the fine detail of this engine. The engines mount screw holes are machined flush which is a feature I have never seen before. The new Cinderella Rich Gold cooling head has a translucent sparkle and the bull printed on the top of the head is a classy Italian touch. The heat-sink head is secured to the engine block by six cap-head screws. The button cylinder head design allows the racer to fine tune the motor to their glow plug preference by offering an optional standard button head piece from the manufacturer. We now stock these head buttons. Under the head: The engine is already shimmed for 25-30% nitro fuel. The crankshaft has a ported center passage with elliptical cuts on the counter-weights along with oil passages where the crank meets the case bearing to help lube the components. The end of the crankshaft has a beveled edge that helps chop up the mixture as it enters the crank port. Admiring the chrome-platted brass design with a total of 7 transfer and boost ports. All the transfer ports have tapered angled channels with fanged out edges. The exhaust port has an internal taper to the port with some notches at the top. The engine receives extremely high marks in this department as it is evident that the power version and the torque version engines are factory modified throughout the products port system. The blocks internal ports provide a smooth flow and transfer throughout the engine block. This engine block also has five integrated fins to help displace the core temp away from the piston and sleeve. Careful when reinstalling the back-plate, the instructions are clear that the piston must be positioned up in the sleeve before the backplate is reinserted as the o-ring sealed plate is milled out to accommodate a portion of the high-silicone aluminum piston when it is at dead bottom. This power version slide carburetor has one low-speed, and one high- speed needle along with one idle screw. ease. This method also reduces strain on a brand new motor during it early phases. Enthusiasts often make the mistake of breaking in the motor cold you do not want to do that with these engines. Heat em up to 200% before starting each time and every time and these engines will last you a life time. We have customers in Australia that swear their Radical 621T is coming on stronger after 5-6 gals of fuel. You will get many gallons of unbelievable performance out of these engines with a little TLC. Any question just shoot us an email. We carry full line of replacement parts. Check out the Yellow buggy with Florescent Yellow wheels with our Radical Red Head 621T at our local in-door nitro track. Team driver Mike battling it out with his racing buddy running the Novarossi based engine. Our Radical engines are factory modified made in Italy beautiful workmanship. Always is stock and on sale at GotNitro.com. Thanks for watching our video!