JS Motorsport
 
 
motorcycle
HIGH-PERFORMANCE
PARTS
FOR NORTON TWINS
JS Motorsport
4480 North Academy Avenue
Sanger, CA 93657
Phone/Fax: 559 875 0659
Email: jim@jsmotorsport.com
JS Motorsport Technical
New gradual ramp JS2 compared to PW3

The PW3 cam is a great cam but the ramps are a bit more abrupt than other Norton cams. We put that right by modifying the ramps so they are more gradual to avoid valve bounce and valve train wear. Now you can have the best of everything - the high performance and wide power spread of the PW3 combined with smoother ramps. The illustration below compares the original PW3 profile and ramps with the new upgraded JS2.

For ease of viewing, the image below has the profiles re-aligned so both ramps end at the short vertical line. You can clearly see that the new JS2 ramp is a more gradual ramp

The lobe centers have been changed from 107 (PW3) to 105 (JS2) to increase performance.