hee hee,,, thanks GR
& i must say you really are taking to this computer technology thing quite well,,, pics & posts & data,,, well done
becarfull tho,,, next we will see you all set up with your dyno hooked via direct link into the web
sgc,,, Morris1100 is right (((To a point))) you can only really (sucessfully) grind the base circle of the cam down so much,,, Most "warm" or hotty road/rally cams can be ground down & (in the process) re-shaped, to affect a different profile/characteristic,,, usually allowing more lift &/or duration.
But if a "Decent" full race cam is desired then it`s best to use a 'Billett", (a blank) which is effectively a piece of solid round rod or bar that is then ground down & shaped into a cam shaft,,, machine the lobes & the gear drive for the dizzy etc,,, harden it & away you go (sort of thing) this way you can obtain a much wider lobe (poor choice of words but still) for longer duration & higher lift is avaliable this way too, without loosing any of the std original base circle.
Welding a std-ish cam up (adding material) is another way of making a bigger cam (egg)
,,, the welded part is often harder than the original cam material (in most cases) & can be good in the respect that the main part of the lobe that cops the heavy treatment/pressure/wear (the top half) of the lobe is pretty dam tough on a welded cam,,, but often it`s the section where the weld starts (the ramp) that can "pit" up or peel or start disintergrating if the weld hasn`t taken very good, or if the profile that`s chosen hasn`t been designed or ground very well,,, it`s that part that is normally really taking the beating,,,---> the ramp up,,, the steeper the ramp, the more crap/pain it cops.
hope that goes some way towards helping you understand , there is obviously way more involved with cams & all the different ways things happen & it`s often called a 'Black Art" , so i`ll leave any more detailed descriptions & explanations to GR & David R & anyone else who cares to add their knowledge into the pot
I know what cams i have used & what they`re like,,, i`ve compared many ,,, i`ve read up heaps ,,, My dad was good mates with Ivan tighe (obviously still is) & i grew up watching them "Play" designing & making new profiles, borrowing other profiles from other manufacturers & generally trying new things,,,
I had one major benefit in all that where i was able to directly compare all these cams with the seat of the pants, driving the minis they were all fitted into
There`s nothing much better than "Feeling" the differences & comparing the stop watch times, in a swag of cams in a pile of minis running at over 8500rpms at places like under the Dunlop bridge at Surfers paradise raceway & Lakeside raceway etc etc , doing lap after lap,,,, tracks like Morgan Pk (when it was dirt) Stanthorp, Dalby, Millmerran, Echo valley (also dirt & also my mosr favourite track
) Speedway tracks all over the place,,, Hillclimb tracks & Autocross tracks all over the place,,, all through my chldhood & intoadult-hood (I`m almost grown up now )
& having a "Play" with different profile cams in the same engines to help gain that edge , get extra grip & drivability etc, (depending on the circuit),,, dirt tracks offer & demand differnt circumstances, needs & approaches to gain that edge,,,, having that experience is what really opened my eyes at the relative "major & minor" changes in a cam designs/profiles,,, it was some wild times back then,,, & just an example of why i keep on about "Horses for Courses" all the time... to me it`s the most important part,,, well most important after the 'having fun" part anyways
I`ll shut up now