Car is a 53 Victoria with 2 x 2 carbs. Just bought a converted SBC distributor with a vacuum advance canister. I'm told to hook the vacuum line directly to the manifold. We took the road draft tube outa the front the the intake, put a grommet in it and stuck a pcv valve in it with a line running from it to the port on the intake- the only intake port. So question is; would we be best off putting the road draft tube back into the intake and run the vacuum advance line to the intake port OR if I put a 'T" fitting in the line running from the pcv valve to intake port and attach the line from the vacuum advance can to that will it operate properly ? Thanks !
I believe both spots are manifold vacuum since they are lower than the throttle blades, for the vacuum advance to work properly it needs to be ported vacuum. Not saying you can't run the vacuum advance to manifold vacuum but it will advance the timing right off the bat.
Road draft tube should be on the back of the block. Front is your oil fill and breather for road draft tube.
Gonna go back to how they engineered it originally- putting the large diameter tube/breather back into the front of the intake. We'll run the vacuum line from the can to a port on the intake as instructed by Charlie Schwendler, who we bought the converted distributor from.
I put my pcv in the road draft hole (which is in the rear on my FE) and hooked the vac advance up to the carb spacer(drilled and tapped) and it runs fine. The road draft tube is OK to use but the pcv is better. You want some sort of baffle in front of the pcv to keep it from ****ing oil.
Keep in mind manifold vacuum was around when cars had 4 or less initial advance so they needed the boost at idle... Most performance sbc need be around 8-14 I initial advance so manifold vacuum does not always work in that regard. I run an accel dual point with no vacuum added... Sent from my XT1254 using H.A.M.B. mobile app
Don't know which 2 bbl carbs you are using but most of them don't have ported vacuum. Just hook the distributer to the vac line on the carb and you should be fine.
I had a single point with a B-1 vacuum can which added 10 degrees of vacuum on top of the initial and mechanical I ran it to both full manifold and ported on my Holley The motor liked the ported better... Eventually I got rid of it because it pinged with the advance Sent from my XT1254 using H.A.M.B. mobile app
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