vacuum advance?

[Coryduran]

How necessary is a vacuum advance? My 65 Dodge Dart GT is set up to have a vacuum advance, but it's not connected. I figured out that it wasn't connected this morning after I couldn't get it to start. I was looking and I saw that it wasn't connected. I contacted the guy who owned the car before me and here is what he said word for word
"When I bought the car it was all out of whack. I checked the initial advance and overall timing. With any decent amount of initial (8-12 degrees) the overall advance would jump way too high (40 plus) above 2500 rpm. Instead of welding up the counterweights in the distributor to take out some mechanical advance, I just bypassed the vacuum canister. It is set right where it should be initial and overall now. If you wanted to run a vacuum advance you could technically remove the counterweights, weld in some material, then file it away until you get the desired amount of mechanical advance, but that would be a lot of work for basically the same end result (possible slightly better mileage)"

So that's where that stands right now. I'm a newbie to this stuff, so I'm kinda just assuming I should listen to him, but I'm wondering how important the vacuum advance is, and if I'd need vacuum advance when I switch the car over to electric ignition.

 

[mac daddy mopar]

you can stick a allen head ( can't remember the size) in the vacuum nipple and adjust the vacuum advance.

 

[rumblefish360]

It's really small, I can't remember right now ethier (5:33 am yawwwwnnnn)
You can dial alot of advance out that way. The vacuum advance should add mileage real well.

 

[Murray]

Not all vacuum advances are adjustable! Most are not. Do not mess with modifications to the advance mechanisms unless you really know what you're doing. Mechanical and vacuum combine to produce a smooth running, economical vehicle.Restore it to original specs.Adjust the points, the timing, check vacuum advance diaphram. A bad diaphram will cause a hesitation.

 

[Coryduran]

Yeah well the previous owner did all the stuff to both mechanical and vacuum advance before I purchased it, and I never noticed until I owned it for a week (Accidentally flooded it, while I was looking around I realized the vacuum advance wasn't connected to the carb, asked the po, and his reply is in the first post) So that's where all that stands.

If I buy a new distributor ( I want a new one that will also convert the car to electric ignition) would that also solve the whole vacuum advance mess?

 

[Gryzynx]

If I buy a new distributor ( I want a new one that will also convert the car to electric ignition) would that also solve the whole vacuum advance mess?

New OEM spec piece ought to do it. Of course, you have to reconnect your vacuum line. Hope it was plugged properly at the source. You may have to undo a lot of the PO mods. Sounds like he had just enough knowledge to be dangerous. I assume the rest of the engine is stock?

 

[Beatnik]

Yea, you should run vac adv on the street. PO did a band-aid fix instead of fixing the issue...

If you converting to an OEM style elec. ign. then I'd suggest FBO's system. www.4secondsflat.com

Give Don a call and he'll hook you up. You could just buy the MP kit too...but Don's stuff is better (IMO) and he'll custom curve/phase the dizzy to your motor specs...

Good luck

 

[dgc333]

The PO of your car does not understand how the vacuum advance works. The vacuum advance ONLY works at part throttle light load cruising when the manifold vacuum is high. Any time you step on the gas or are under load such as going up a hill the manifold vacuum is close to zero and the vacuum advance does not add any timing.

With the initial set at 8-12 degrees and getting 40 above 2500 rpm you will need to weld slots or get a distributor with an adjustable mechanical advance. The vacuum advance being disconnected will not fix that.

Under the fore mentioned light load conditions you want your initial + mechanical + vacuum advance to be on the order of 50 degrees or more. I would go ahead and connect it, it won't hurt anything and will give you better economy while cruising which is why it's there.