what do you guys like to set timing at on a carb'd engine?

i have been setting mine 8* with the vaccum advance off and plugged. after i plug it back in, the timing jumps up to 22*, and is at about 34* @3000rpm. is this normal?

i have a 350 with a mild cam, and a 650 holley. the vaccum gauge says the engine is making 15" of vaccum.

should the timing jump up that much at idle?

 

pretty much normal, the vacuum is pulling at idle and making the timing advance. if you had no vacuum to it at idle it's stay where ever you set the base timing at.

 

sounds like you have your vacuum advance plugged into "manifold vaccum", it should be plugged into a vacuum port ABOVE the throttle valves. there should be no vacuum adavance at idle speeds. On holley carbs, the port your looking for is the highest one on the carb.

set up a vaccum guage to manifold vacuum, and turn the distributor until max vacuum is acheived, with the advance un plugged. which is around 8-12 degrees on a typical SBC. total advance should be around 36 all in at about 3200. thats with the vaccum advance unplugged. of couurse, every combo is different

 

well i've heard two different answers from many different people now. some say that i should have no vaccum advance at idle, and some say 22* at idle is fine

does any one know for sure?

 

either will work, depends on how you want it set up. most street applications will see no vacuum at idle to the vac advance. it all depends on how quickly you want to get to full advance.

 

ahh ok, so there isnt a right and a wrong way, just different ways todo it.

thanks ede!