Camshaft Differences

[joedrum]

hmmmmm ...in my case .. perfectly good stock carb racks that worked good on 1100s with early cams in them didnt work on the 1200.....with its longer stroke ... this whole deal has had me going awhile .. some who have done this mod before me seem to never say a thing about ever having a problem here ...making me think there stories a bit off ... the people i know about that went this way all had trouble with carbs ....as slab was saying about the biggest difference here is just in head shaving ... way of valve relief .....but now it also involves ignition and induction system ....the other big deal going on past stock carbs not working ...was the accross the board 0-to redline power band my bike has ....

with the 2 stage weber progressive carb...it is a scary game digging into secondary low in the rpm ... the times i have ...stopping the bike safely was next thought ....the down low power is something i stay away from .. to hard to control...from a cam in the stock version has no low rpm power at all ...compared to hooch...i think its a collection of things that leads to the big differences not just one ..as i see things ...all together seems to be a big deal ... there is no more sane power to go for in a all purpose dependable bike ... surrounding parts are maxed out in my opinion :ahem:

 

[ekvh]

MSGT-R, don't know if you're still around or too busy with your F6b, but I was wondering how much difference is in the base circles of the 1000 and 1200 cams. I didn't note any measurements just that it was a fatter one. Thinking about regrinding a set of 1200 cams to match 1000 lift and use in early heads. Should give a big bump in duration and overlap. By my guesstimating it would only need to be a mm larger, and you description makes me think it's more than that.

 

[ekvh]

Got a chance to compare the base circles of the 1000 and 1200 cams. I believe there's a little optical illusion due to the differences in design, but the base circles were/are the same. The rocker arm ratios are also the same. So dropping in 1200 cams from an 84-85 year will gain ten degrees overlap but give up some lift. Grinding the 1200 cams to gain a larger lift will result with a pretty small base circle. IMHO, you're better to grind the 1000 (75-77) years if at all. Finding a set that isn't worn down would help.