Vacuum advance troubles ????

thegavel

thegavel

Active member
Joined
May 26, 2008
Messages
29
Location
Melbourne, Australia
Seasons Greetings ALL,
Dumb question time.
How do I tell if the Vac advance unit is faulty???
It's on a standard points type dizzy (with pertonix conversion).
I've tried looking for movement but it's almost impossible to see it.
I was checking the timing yesterday and didn't notice any
difference (in timing) with the vac hose on or off.
I even tried sucking on the hose (to see if it was on the
wrong vac port on carb)but when i did I got no resistance!!
It was like well.. sucking on a hose not connected to anything, I thought it would seem blocked.
Is this right?????
MANY THANKS
Have a HAPPY & SAFE NEW YEAR.
CHEERS
GAV
 
010752 said:
Connect a hand vacuum pump to the VA with the engine running, carb ports capped and timing lite connected.
You will then see at what vacuum it changes the timing and by how much if any.

Using the above together with a regular vacuum gauge and tach and you have yourself an on car distributer machine.

Here is a cheapie.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474
Click to expand...

You can also do that on the bench to merely check movement/leak down.
If it's an adjustable can, throw it away. They are junk. Get the right can.
 
You say it's like nothing on the other end of the hose, assuming it's connected directly to the dizzy vac advance can, and not through some other device, I would say the vac advance can is bad.....may try another hose piece, if you suck on it hard enough, you should hear the idle speed pick up a bit...and to see if the carb point has vacuum on it...just hold you finger over that port....

I would put the vac canister to a point that is always full manifold vac....

that way you will pick up some idle speed, but then you can lower it down again, and in so doing, probably have less dieseling/run on when the engine is hot in summer....

:drink:
 
mrvette said:
I would put the vac canister to a point that is always full manifold vac....

that way you will pick up some idle speed, but then you can lower it down again, and in so doing, probably have less dieseling/run on when the engine is hot in summer....

:drink:
Click to expand...

Yep. That too. Ported vacuum was just an EPA trick to lower recorded emissions at idle.
 
big2bird said:
mrvette said:
I would put the vac canister to a point that is always full manifold vac....

that way you will pick up some idle speed, but then you can lower it down again, and in so doing, probably have less dieseling/run on when the engine is hot in summer....

:drink:
Click to expand...

Yep. That too. Ported vacuum was just an EPA trick to lower recorded emissions at idle.
Click to expand...

Mrvette is the king of suck' I'm about to install his new suck induction supercharger, will that act something like a vac advance or a real blow hard? I'm confused.:stirpot:
 
big2bird said:
DARROW 74 said:
What year did they start using vac advance.
Click to expand...

Somewhere between 1933 and 1937.
Click to expand...

OH man, I think Ford learned advanced sucking about 37 or so, as in a old buddy had a 35-6? Ford Rumble seat convertible, had the obvious fathead V8, and he had all sorts of starting/running/idle problems....with dead stock dizzy, I finally convinced him to stick a vacuum advance on it, from a later car....which did cure his problems, like the hydraulic brakes modification that made the car safe to drive, the vacuum advance made it driveable.....he never lost much points I suppose as he had a few V8 show awards....
funny in that Mike knew all about drones and those spy/drones they fighting with in Afgan, he built the early models for the Navy....but when it came to the cary hobby and that sort of mechanicals, he had a learning curve....something I would think would be done by osmosis from HIS field....

:crutches::bonkers:
 
mrvette said:
big2bird said:
DARROW 74 said:
What year did they start using vac advance.
Click to expand...

Somewhere between 1933 and 1937.
Click to expand...

OH man, I think Ford learned advanced sucking about 37 or so, as in a old buddy had a 35-6? Ford Rumble seat convertible, had the obvious fathead V8, and he had all sorts of starting/running/idle problems....with dead stock dizzy, I finally convinced him to stick a vacuum advance on it, from a later car....which did cure his problems, like the hydraulic brakes modification that made the car safe to drive, the vacuum advance made it driveable.....he never lost much points I suppose as he had a few V8 show awards....
funny in that Mike knew all about drones and those spy/drones they fighting with in Afgan, he built the early models for the Navy....but when it came to the cary hobby and that sort of mechanicals, he had a learning curve....something I would think would be done by osmosis from HIS field....

:crutches::bonkers:
Click to expand...

Studebaker pioneered it in 1930. Chrysler introduced it in 1931. Chevy and Buick followed suit shortly thereafter. The 1938 Delco had it for sure, as I restored one.
 
SmokinBBC said:
Gav...you figure it out yet?
Click to expand...

Yeah it looks as if the vac advance can is history.
I got the wife to do some foot work while I checked it out,
Nothing,no movement at all, but there was definately vacuum from the hose.
So I'll be pulling (Not sucking LOL) the dizzy
on the weekend and getting replacement parts.
Hopefully the can is available here in Oz.
I don't want to wait too long to get HER back on the road,
It's Summer down here so the shows and runs are getting underway.
You guys have come thru again,
Thanks muchly
CHEERS
GAV
 
I would look in the Tech section for the proper vacuum can for your application.
 
Well, who would have guessed?????
The good lady wife :1st:must have been paying attention to (at least) some of my rantings.
She's gone and bought me a CRT Performance Tach drive Dizzy off feebay
(Right dizzy,Right engine type -YIKES).
Okay it isn't an MSD but it'll do.
Jeez I'll have to watch what I say from now on,
maybe if I mention the SS Twin turbo C3 on feebay enough
she may buy that for me (YEAH RIGHT !!!).
Any tips or hints on installing/setup would be great.
Again thanks to everyone here for your help & patience.
TO ALL HAVE A GREAT NEW YEAR & DRIVE SAFELY.
:drink:
CHEERS
GAV
 
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