This is the Sirio S21 CL7R STI On-Road Competition Buggy Engine. Sirio engines are made from the finest alloys and composites in the industry and the back to back 1/8th On-Road IFMAR World Championships and the 2004-05 1/10 IFMAR World Championship speak volumes when it comes to performance.

Sirio has introduced their STI line up of engines. STI engines have all the "extra" touches that a true "team" engine has and they are now available to the public.

STI engines feature serialized crankshafts, cases and rods for better quality control. Each crankcase is hand selected and blue printed for the best tolerances. The sleeve is hand matched to the case to improve the flow through all the ports. The connecting rod features a surface treatment that ensures maximum strength. The crank shaft has an aerospace coating to improve durability and performance. Premium bearings are hand matched to the crank shaft and case tolerances. Add this all up and you have true factory team performance.

Features

• Blue cooling head with Sirio logo on top
• AAC ( aluminium ) piston and cylinder
• 7 port cylinder with 3 more for exhaust
• Modified crankshaft for more power in both low and high rotations
• Inside bearing is ceramic for longer durability
• 4 needle alumínium carburettor
• Rear exhaust engine

Specifications:
Displacement: 3.5 cc
Stroke: 16.90mm
Bore: 16.20mm
Ports: 5+2
Piston: CNC
Sleeve: ABC
Exhaust: Rear
Weight: 322 grams
Crankshaft: 14.20mm SG Type
Carburetor: Composite / Slide / Double Adj.
Plug Type: Turbo