O.S Engines Pro modified .21 VZ-B V-Spec

New from O.S Engines, is the pro modified version of the .21 VZ-B V-Spec, which sports special enhancements for exceptional performance. Every upgrade to the engine is done by hand in the U.S. by a skilled technician, and all for the aspiring racer who wants a performance advantage over the competition running stock. The upgrades include a hand selected and matched piston and liner, a drilled out cylinder head for lighter weight and better cooling, the engine gets a ceramic rear bearing, while a special coating on the lightened crankshaft prevents wear and finally tungsten weights in the crankshaft improve balance at higher RPMs.

Specifications:
Displacement: .211 cu in (3.46 cc)
Bore: 0.654 in (16.6 mm)
Stroke: 0.63 in (16.0 mm)
Practical rpm range: 3,000-40,000
Output: 2.48 hp @ 33,000 rpm
Weight w/o muffler: 12.7 oz (360 g)
Includes: 21JS carburetor & 7 mm carb restrictor

Source: OS Engines [osengines.com]