Myself and a relative were discussing the correct place to hook up the vacuum advance on a Holley...we had a shop install a 750 DP Holley and I was trying to describe to him how they hooked up the vacuum advance but he didn't seem to understand what I was describing, so I took this picture and emailed it to him. Maybe somebody here can tell me whats its supposed to be for. The advance is hooked up to a 90 elbow coming out of the area near the electric choke housing. If you try to disconnect that vacuum line from the carb, that elbow will probably come out with it, and then you have to fight to press the fitting back in. Is this the right place to have the vac advance hooked up or should it be teed into the metering block fitting where the other line is hooked up for the trans? Or it should be hooked up somewhere else? TIA
NO, no, that location is for the vacume advance .... The trans vac hook up is at the back of the intake manifold.... The little nipple under the choke can be capped.... That is on a nailhead engine,,,, the engine in the pic appears to be a 350 or bbb.... the location of the trans vac should go into the intake on those , also at the back... but not sure about all years.... Personally , the way I hook mine up is to have both the trans vac and the dist vac go into a ''direct'' vacume source that is below the butterflys of the carb,,, that gives vacume all the time except at wide open throttle.... increases response and gas mileage...
The car used to have a 350 trans with the vacuum hooked up at the back of the intake, now it has a 200-4R...the vacuum switch is for the torque converter lockup and is supposed to be connected to a ported source. It sounds like I'm going to have to tee into that line to get the vacuum advance hooked up correctly. What is the nipple thing under the choke for? The engine is a 455.
Nobody knows what that fitting is for? Well anyway, heres what I ended up doing. Plugged that mystery fitting and teed the vacuum advance into where the 2004R TCC vacuum switch went into the carb: After that, tuned the idle mixture and idle speed. The engine does seem to run a little smoother at lower RPM. :grin:
The nipple under the choke is for the choke pulloff piston. Should go to manifold vacuum. http://www.chevelles.com/techref/Adjusting_Automatic_Chokes.htm
