The 509 Touring Cam is designed as a bolt-in, high torque cam for 1999-'06 models, except 2006 HD® Dyna®. 180 psi cranking compression, no need for compression releases. For 88 CID engines with stock compression ratio. Idle-4500 rpm. S&S 551 cams for Harley-Davidson® touring bikes have become a favorite with late model bagger riders. The problem is that, due to the .550" lift, the 551 cams can't be installed in early (1999-'04) Twin Cam 88® engines without installing a set of high lift valve springs. That means that the heads have to come off just to install a cam. That's a lot of work and expense!
