The 21XZ-B Spec III is that latest evolution of the popular 21XZ-B racing engine from OS. OS are known worldwide for developing race winning 1/8th Off Road World Championship engines and this latest iteration is a result of constant refinement. Using the latest OS design techniques and technology lots of small improvements have added up to a noticeable step forward in performance. These improvements not only enhance the outright performance but also the drivability and usability in high pressure race situations.
• The Spec III has a long stroke for optimum torque • Improved low-to middle-range torque for corner exits • 3 scavenger ports and 3 exhaust port cylinder • Reduced weigh head for a lower CG • DLC-coated crankshaft with pressed-in tungsten weights • 21J carburettor with 6.5 mm restrictor
Note: This engine does not include a tuned pipe or manifold
