Best place to hook up vacuum gauge on Edelbrock carb (permanent and temporary)

[ChuckN]

The Eddy carb has limited ports.
The trans modulator is connected to a fitting on the manifold itself, the rear (large fitting) is used by the brake booster, and the front is used for full manifold vacuum for the timing advance (not ported vacuum, the full vacuum fitting). If I tee into the vacuum advance line for the gauge, will that throw the signal off to the advance? The purpose of this is for carb tuning (metering rods and step up springs) and if it affects the timing that would ruin any accuracy. Post your suggestions, thanks in advance.

Chad

 

[legopnuematic]

You should be fine teeing into either. The “cleanest” would likely be to find a fitting for the manifold with two barbs:

You must be registered for see images attach

Quite a few varieties that are available, a little looking may be needed for the most ideal configuration.

 

[83Stepper]

Agreed on putting a tee onto the back of the manifold behind the carb.

Any reason on why you'd want a permanent mounted vacuum gauge? If you do permanently mount it, I would go with a hard line over any other tubing.

 

[ChuckN]

Agreed on putting a tee onto the back of the manifold behind the carb.

Any reason on why you'd want a permanent mounted vacuum gauge? If you do permanently mount it, I would go with a hard line over any other tubing.

Oh, mostly for tuning the step up springs in conjunction with the AFR gauge so I can tune how quick or slow the fuel comes in- so I’ll need it in the cab with me.

The main reason for the question is I wasn’t sure if vacuum gauges in general were “dead head” or if they had any flow through effect.

 

[ChuckN]

You should be fine teeing into either. The “cleanest” would likely be to find a fitting for the manifold with two barbs:

You must be registered for see images attach

Quite a few varieties that are available, a little looking may be needed for the most ideal configuration.

That’s a great idea, I didn’t know they existed. Thanks!

 

[legopnuematic]

I’ve got a vacuum gauge that lives on the column of my 76 next to the tach.

This is an old picture, truck has an Autometer tach in it now:

You must be registered for see images attach

The wideband O2 gauge lives in a little panel I made that is mounted below the radio.

Personally I really like having both the wideband and vacuum gauge as a permanent fixture of my vehicles.

 

[ChuckN]

I’ve got a vacuum gauge that lives on the column of my 76 next to the tach.

This is an old picture, truck has an Autometer tach in it now:

You must be registered for see images attach

The wideband O2 gauge lives in a little panel I made that is mounted below the radio.

Personally I really like having both the wideband and vacuum gauge as a permanent fixture of my vehicles.

That’s the way to do it.

 

[Ricko1966]

Agreed on putting a tee onto the back of the manifold behind the carb.

Any reason on why you'd want a permanent mounted vacuum gauge? If you do permanently mount it, I would go with a hard line over any other tubing.

For one you can see engine problems before you feel them. For another you can taylor your driving habits for better MPG.

 

[83Stepper]

For one you can see engine problems before you feel them. For another you can taylor your driving habits for better MPG.

Maybe I'm just too old school for that lol. Always went by drive and feel over any mechanical gauge, aside from oil pressure and temp.
Definitely know I didn't buy any of my squares for fuel efficiency. Never had one that was economical by any means, especially my 71 full convertible or 80 full time K5 Blazers.

 

[ChuckN]

Maybe I'm just too old school for that lol. Always went by drive and feel over any mechanical gauge, aside from oil pressure and temp.
Definitely know I didn't buy any of my squares for fuel efficiency. Never had one that was economical by any means, especially my 71 full convertible or 80 full time K5 Blazers.

Absolutely. For myself, I’m not looking for efficiency, just wanting to time the carb since in some areas it is rich, and others too lean depending on where the throttle is at.

 

[Ricko1966]

Maybe I'm just too old school for that lol. Always went by drive and feel over any mechanical gauge, aside from oil pressure and temp.
Definitely know I didn't buy any of my squares for fuel efficiency. Never had one that was economical by any means, especially my 71 full convertible or 80 full time K5 Blazers.

Old cars used to have vacuum gauges, factory.

 

[legopnuematic]

Old cars used to have vacuum gauges, factory.

Like this one I have from a 50s International truck:

You must be registered for see images attach

 

[Camar068]

Oh, mostly for tuning the step up springs in conjunction with the AFR gauge so I can tune how quick or slow the fuel comes in- so I’ll need it in the cab with me.

The main reason for the question is I wasn’t sure if vacuum gauges in general were “dead head” or if they had any flow through effect.

a vacuum gauge should be no flow. Take a mechanical and put a hose and syringe on it and pull. It should stay steady with no movement to the needle provided the syringe plunger doesn't move. If it doesn't you have a leak in the hose connections or the gauge is bad.

Another way to test a gauge would be to pull a vacuum and clamp the hose closed with vice grips or hemostats. Let it sit. If it moves....you've got a leak. How quickly it moves over time depends on how big the leak.

Lets say you want to test for leaks now or years down the road. Start it up and spray starter fluid on the gauge, fittings, hose. If idle changes, you've got a leak.

A vacuum gauge is also useful for troubleshooting other stuff as well. Once installed it's good to make a mental image of what it's doing at idle. You'll notice when it's different and can jump on things earlier.

You must be registered for see images attach

 

[83Stepper]

Absolutely. For myself, I’m not looking for efficiency, just wanting to time the carb since in some areas it is rich, and others too lean depending on where the throttle is at.

I get that for sure. I've done most of my dialing in at about 2k rpm's with the throttle screw dialed in and tuned them to maximize the reading there. Haven't felt the need to have one connected full time while driving. But I can definitely see instances where that could be useful.

 

[1lejohn]

I connected my gauge to the vacuum line running to the HVAC controller.