i am going to port the head on my ds 650. does any one have any good advise on this subject? i have to take the head off any way so i thought as long as i am there why not. i have stock cams so will porting hurt me if i do not have the cams to go with it? i plan on doing cams ladder on.

 

Ideally when you port a head, the cams should be designed to go with the improved flow. Keeping stock cams and porting a head could actually set you backwards a few notches. Normally after a porting job is done for a particular engine, the engine is dynoed with a cam which has been cut to be theoretically correct for the motor (taking intake and exhaust flow into account as well) and then it is recut(the cam) to optomize the result...That is how it should really be done.

That is why when having a head ported it is important that you purchase the cam from the same engine builder if they are a reputable house, as he will have the best idea of which cam best matches the porting. IE TC racing or Powroll who have done the development work for the whole package and developed kits which work well together. These are not the only houses of course which do good work, but simply examples.