Wossner forged piston kit with an 89.02mm bore, designed for KTM EXC 450 Racing, Beta RR450, and Polaris Outlaw 450 MXR models. Engineered for optimal combustion chamber heat transfer and uniform bearing surface under heat expansion, reducing localized pressure and piston collapse. Manufactured in Germany for durability and precision.

Features

• Forged piston for superior strength and design


• Optimized heat transfer to cylinder walls


• Elliptical design for uniform bearing surface and even thrust load distribution


• Manufactured in Germany

Specifications

• Bore: 89.02mm (+0.02mm oversize)


• Standard size piston (PN# 8581DC)


• Lock Part Number: CW20


• Pin Part Number: WP038


• Ring Set Part Number: 890XSY


• Displacement: 449 cm³


• Stroke: 72.00mm


• Clearance: 0.04mm


• Wossner Compression Ratio: OEM


• OEM Compression Ratio: 11.10:1


• Dome Volume: +7.10 cm³


• Compression Height: 23.50mm

Cross-Reference OEM Part Numbers

• Not provided

Vehicle Fitments

• KTM EXC 450 Racing (2003-2007)


• Beta RR450 (2005-2009)


• Polaris Outlaw 450 MXR (2008-2011)