O.S. ENGINE MAX R21 GT- 5 PORTS - TUNED VERSION -

O.S. MAX R21 GT 5-port tuned engine developed for modern high-performance GT racing.

Today's GT cars can convert the power of tuned 3.5 cc engines into real lap-time gains rather than simply wheelspin. The R21 MAX pushes the 5-port concept with highly developed exhaust-port geometry while remaining within 5-port regulations.

The engine also features a cooling head approximately 9 g lighter than the standard version.