The Ilmor 'C-Flex' billet motor mounts feature a proprietary floating saddle clamp (patent pending) on the rear support of the mount that: STATIC - Allows the mount to sit flat on any chassis - Ilmor's floating saddle clamop will take in and compensate for any offsets in the chassis rails Elimates the need for unique custom machined mounts Relives the chassis and engine from any static stresses generated when tightening the engine clamps Even chassis' with badly misaligned motor mount tubes DYNAMIC - permits quick tuning to significantly free up the chassis; simply adjust the floating saddle clamp set screws - unlike the traditional mounts which require the third bearing carrier to be disconnected or even modify the chassis to free up the kart. isolates chassis from the rigidity of the engine-mount assembly - allowing the chassis to flex as the track conditions demand Isolates engine from chassis twisting motion - preventing the bottom end of the engine binding as the chassis flexes. Binding the bottom end of the engine will increase frictional losses which ultimately translate into engine performance losses and increased wear and tear. NOTE: Motor mount clamps are sold seperately.