This is the Novarossi KEEP-ON.21 9 Port .21 X-Long Stroke On Road Engine. This engine features a patented Novarossi main bearing found only in the KEEP-ON line of engines. This bearing has a narrower center ring compared to the outer ring providing reduced rotating mass, with increased acceleration and throttle response. The KEEP-ON.21 engine also features an extra long stroke providing more bottom end power. This engine also features an o-ring supported combustion chamber, as well as a "Tuned" crankshaft with reduced rotating mass and improved fuel flow.
- Cooling Head: This 'Lighter and Lower evolution 2' type cooling head has been drilled and milled out to reduce the mass of the cooling head, reducing the Center of Gravity of both the engine and car.
- Conrod: The R7 conrod is made from a super light aluminum which has been checked ultrasonic. The specific form of the R7 creates little turbulence inside the engine while running.
- Rear Cover: The rear cover presents a round shape to optimize the filling and reducing the dead spaces. The steel plate is to reduce friction and to expand the lifespan of the conrod.
- Sleeve: The sleeve has 9 transfer ports and an exhaust with booster ports. The special shape and positioning of the ports, covered by a patent, improve the internal fluid-dynamics to obtain the maximum possible performance.
- Gasket: The inner shape of the gasket has a new shape, and with that more material. Together with a change in material these gaskets are more resistant to high temperatures.
- Crankshaft: The crankshaft has been ground to increase the mixture flow and has a special shape to reduce turbulence inside the crankcase. The balancing is done by 3 inserts made of tungsten alloy and the inlet has a silicone filling to reduce the weight of the crankshaft for improved acceleration.
- Glowplug: The glowplug of the engine is a Turbo type glowplug. Turbo glowplugs have a different shape than Standard glowplugs and therefore are not interchangeable with engines that use Standard glowplugs.
- Compression Rings: The ignition timing is controlled with these little rings of various thickness. To change the ignition timing you can add or remove a ring of a certain thickness.
- Rear Ball Bearing: The unique rear bearing reduces rotating mass and increases the engines scavenging, providing increased throttle response and a higher top speed.
Max Power: N/A
Practical Range: 6,000 ~ 46,800 RPM
Bore x Stroke: 15.88x17.60mm
Transfer Ports: 9
Ball Bearings Front: Steel
Ball Bearings Rear: Ceramic
Crankshaft Type: 14.5mm - TURBO SG 'TUNED'
Carburetor Type: 9mm Slide
Carburetor Material: Aluminum
Glowplug Type: Turbo - C8TGH
Exhaust Position: Rear
Fuel Type: Advise; 25% Nitro