vacuum hose positions

[AusRs]

Help
so many ports on the Carb ..so many not needed to be used (no emissions testing on this car ) .........

i need to know which ones to block and which ones to use
do i pull the vacuum from the manifold for the booster ?

thanks in advance

[cjbiagi]

There are only two types of vacuum ports, ported and full time. Ported means there is no vacuum available at idle and full time means it has vacuum all the time. There may be multiple ports but they are all going to be one or the other. Now it depends what you are connecting them too. The one for the trans is full time as well as the brake booster. The advance on the distributor can be either, stock it is connected to a ported source but some cars like full time so try both and see what works best. There were a lot for the emission stuff, many worked through vacuum switches that were temp controlled or controlled in some other manner. Tell us what you are hooking up.

[AusRs]

Thanks Clyde
I am hooking up the trans ,should i do that direct from the manifold like it was ?
pcv
choke
vacuum advance (will use ported vacuum )
power booster line

think thats about all i will need ! have i missed anything ?

[spyder_xlch]

I've always refered to it as ported or manifold vacuum. Ported vacuum is any vacuum port above the throttle plates, manifold vacuum is anything below the plates. The power brakes and PCV can be hooked up to the intake manifold or a large port on the carb that is below the throttle plates. The choke pull off should go to ported vacuum. Vacuum advance can go to either like Clyde said (you may want to try both ported and manifold vacuum). The trans goes to manifold vacuum.

[MIKESMONZA]

?: My original 77 2 Barrel Rodchester Carb, 305/Four Speed, Power Brake's Mirage,
has a tiny funnel shaped amplifier installed inline,
on the Vacumn Line for the HEI Vacumn Advance Pot two inches away,
Is this Factory?,,or Normal,?

I have seen these on diferent GM Model's,
and only know that it is a Amplifier and would guess it has a directional desighn
Also could be not original Equipment ?
but could effect the timing??
Any body know why or have an Opion?

The vacumn Booster for Power Brakes is ported to Carb Bottom,,,,Edit 08-02- 08 the Power brake Booster is conected to Carb Base not ported but full time.
As I Remember The factory Pvc Hose is To the front of Carb or 2bbl intake manifold,foward driver side,,,,below carb mount
near Intake Runner,

As A Former Owner Lost Or Swaped the Original intake,,,
and used a Factory alluminum 2BBL intake in its place,

The Thermostat housing has vacumn ported screw in Temperature controled,,
hose's for Vacumn hook up to EGR unit for the crossover Exhaust ButterFly
and has a line for the Distrbutor Vacumn Advance disconected
Also has the Vacumn for the vapor canister for the gas Tank
They use a Info decal on most cars today,Tune up and Emissions,,
They have had GM body part number's in the past (For body dammage replacement,mostly
to let you trace the Componets on most set ups
some are on the Air Filter Canister' some have ended up on the Core Support of Later car's
and probaly have Vendors on E/bay making replacement's,
And has been on post's on the Old Site,
The emmissions decal for the 75 thru 80 camaro with 2bbl 305 would be a nice accesory as also the 75- 80 camaro 350 would be close,
but probaly no hose routing,

On my other car
The 75 V8 Intake is a Edelbrock Performer,with the vacumn for accesorys plumbed in to it,
But the Brake Booster is Plumbed in to the Base of 1406 carb
with the Adapter Pipe Bushing from Original two barrel carb along with metal pipe,

The Carb on 1406 has a distributor vacumn tube on front,, actualy two like Clyde descibed.
one Timed and one full time, I use a Full Time vacumn with the HEI on Mine,

Thanks
Mike

[spyder_xlch]

The vacumn Booster for Power Brakes is ported to Carb Bottom,

That's actually manifold (or full time) vacuum, not ported. The port is below the throttle blades.
I don't recall seeing a funnel shaped amplifier but a filter is quite common.

[MIKESMONZA]

Spider ;Your right on the Vacumn for brakes , I realy should have Said,,, Plumbed to Carb Base !
Not Ported to carb Base!

Also Thanks for the Filter Ideal
as maybe it can be checked for Vacumn reading's on both side's to see the differance's
and it's possible use in removing "Moisture" ?? from HEI Vacumn Advance Line,or maybe Pulse's.LOL

A "Filter" is alway's misconcevied in use of automotive and Electrical and hydraulic,
Maybe HG /Vacumn
I know I am confused.
Mike

[spyder_xlch]

I don't really know what the "filter" does but that's what it's called. If I had to guess I'd say it stops fuel vapors from getting to the booster diaphram.

[SunbirdMan]

?: My original 77 2 Barrel Rodchester Carb, 305/Four Speed, Power Brake's Mirage,
has a tiny funnel shaped amplifier installed inline,
on the Vacumn Line for the HEI Vacumn Advance Pot two inches away,
Is this Factory?,,or Normal,?

My 1978 305 automatic has a vacuum delay valve installed in that line. I thumbed thru my 1978 Monza Manual vacuum diagrams and the only vehicles it shows one in that line are California 305s. But that's for 1978, maybe 1977 has something different.

[spyder_xlch]

Maybe what Mike has is a check valve to hold vacuum in the event of a stalled engine so you still have power brakes (enough for one pump anyway)?

[MIKESMONZA]

Bought car in 2006? off E/Bay It Was in California Near?? UKIAH,,? Mike