This is the Werks Racing B5-Pro .21 Off Road Racing Buggy Engine. FEATURES: ABC cylinder construction, "A"luminum piston with a "B"rass liner that is "C"hrome plated Five port liner High-silicon aluminum alloy piston 7075 T6 knife edge connecting rod 2 needle slide valve carburetor with adjustable venturi CNC machined & lightened low GC cooling head Turbo head button INCLUDES: Werks Racing B5-Pro .21 Off Road Racing Buggy Engine with #5 Turbo Glow Plug, silicone exhaust gasket and parts list REQUIRES: Fuel: 10-30% nitro content, 20% recommended for break-in Exhaust System: Depending on vehicle Glow starter, fuel tubing and track equipment SPECS: Displacement: .21 cu in (3.4cc) Stroke: 0.649" (16.50mm) Bore: 0.64" (16.30mm) RPM Range: 3,000 to 39,000 Output: 2.6ps at 33,000 rpm Mounting Hole Centers Same Side: 0.83" (21mm) Mounting Hole Centers Opposite Side: 1.5" (37.5mm) Crankcase Width below Mounting Tabs: 1.2" (31mm) Width of Mounting Tabs: 1.7" (44.4mm) Height from Mounting Tabs to top of Cylinder Head: 3.7" (94mm) Cylinder Head Diameter at Top: 2.3" (59.9mm) Length from Backplate to Front Bearing: 2.5" (63.3mm) Length from Backplate to End of Crankshaft: 3.7" (93.2mm) jxs 07/11/11 ir/jxs