vacumm tuning carburetors

[sleepychallenger]

What are the vacumm readings suppoesed to be when at idle and when reved? also, where would you reccomend tapping into? i have the carter AVS and tapped into the back of the  carb.

[Chryco Psycho]

depends on the cam , idle vacuum can range from 3" - 20"

[sleepychallenger]

i have a hemi grind cam from comp cams in there. the vacumm guage is reading 0-1" at idle and about 15-17 when the rpms are increased

[solarguy]

Some pretty good reading here............http://www.secondchancegarage.com/public/186.cfm

[sleepychallenger]

the article doesnt say but are those readings at idle? did i hook up to a bad port for vacumm?

[Chryco Psycho]

it is acting as if you connected to the ported vacuum for the dist , you vacuum should be higher at idle
 so right now hooked to the large port for the power brakes you only have 1 " of vacuum at idle ?

[sleepychallenger]

no, i hooked to the small port at the back of the carb. Vacuum advance is in the front of the carb. i havent hooked into the brake booster because i do not have a big enough vacuum hose to tap in there and hook to the guage. from where i hooked up on the carb, i only have 1" vacuum at idle. when reved it goes up to about 15". the port is the one that you hook the vacuum hose to for the air cleaner snorkels