nutsy

after putting a new distributor vacuum advance on do i need to adjust anything? thanks.

S489

short answer: no
IF you replaced the correct advance "in kind" on an otherwise well tuned engine . . . (this assumes you checked the timing after replacement)

7T1vette

Only that it really works! {Lots of 'new' parts don't, anymore.} I would put the timing light on it just to check.

cardo0

All the vac cans are rated for certain vac. Like some have full adv at 18" Hg and some at 22" Hg. U can find out what your eng needs by using a vac gauge (most fuel press gauges are vac too or use a mighty vac brake bleeder gauge). Connect the vac gauge to the intake and measure vac at your normal eng idle (450-900 rpm). Next rev the eng untill the secondaries open. *Warning don't WOT the eng without a load on eng and overrev it* - u will destroy the vlv springs. Just rev to 4000rpm max and measure eng vac.
Now u know your eng idle vac and WOT (next best thing) vac. U need a vac can that has no adv at WOT and full adv at your normal idle rpm. U can check any installed vac can by taking off the dist cap and connecting a "Mighty Vac" brake bleeder and watch where the can starts to pull in (WOT) and and where full adv (idle) is on the "Mighty Vac" gauge.

That's as easy as i can make it for u. Now u can shop for the right vac can yourself.
Hope this helps,
cardo0

Roarinbear

Not to hi-jack this thread, but, can an adjustable vacuum canister be used?

cardo0

I can't see from here in California how your adj vac can works in NH. But u can test it and set it just like how i just described.

cardo0

Roarinbear

Thanks. Didn't know if it would be easier, or better.

FB007

I wouldn't. They are inconsistant POS's.

FB007

There is no manifold vacuum at WOT.

baxsom

i didnt think that the secondaries would open in park

Reggie Dunlop

Adjustable cans are like anything else - just buy a good name brand unit. I have used several and have never had a problem. I have the Accel on my '79. It's been there for about a year on a car that I drive 60 miles everyday. I have the Crane unit on a '77 Pontiac 400 - it's been there since '03 and has over 50,000 miles on it and still works just fine - and I have the Proform (came on the dist) on a '72 Chev K20 - again no problems in over 3 years of occasional use.

cardo0

Really? Then how does air (and fuel) move through the carburetor and into the combustion cylinder? Just PFM?

Someone or more than one here needs to go out and measure thier eng vac with the secoundaries open.

cardo0
This thread isn't just hijacked its trashed. Too many posting info they need to prove to them selfves instead of expecting others explain the very basics to them.