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New Vacuum Advance
Posted by: Duane1967 ()
Date: November 23, 2012 11:55AM

Are all vacumm advance units the same, or are each one different based on the yr/engine/transmission and distributor?

I've seen you can take a socket and increase/or decrease the way it operates by bending it, or increasing the dimple, BUT, if I just want to get a new one, which one do I buy? (if there's more than one) I have a 67 95HP/slip and slide.

Thanks! I'm sure no one will answer right away. I know you are all out Black Friday shopping???

Duane
1967 500 Coupe
Folsom, CA (Sacramento suburb)


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Re: New Vacuum Advance
Posted by: MattNall ()
Date: November 23, 2012 12:02PM

As far as I know.. there are only one or two models still available...but looks like one dozen different units were used originally.

I'd just buy one and see how it works for you..

"psi' units are for turbo's


Most likely your 67 falls into the last dozen listed here.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
...............110-PG.................................................Webered-Turbo




Edited 1 time(s). Last edit at 11/23/2012 12:04PM by MattNall.

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Re: New Vacuum Advance
Posted by: jimmyo ()
Date: November 23, 2012 12:34PM

They're not easy to read, but I hope this helps you. Also only a few different vacuum advances around. You can cross reference your distributor on the top chart with the vac advance on the bottom.

Jim O'Connor
45 miles north of The Bronx, N.Y.
1962 Greenbrier 110 4spd
1964 Monza Convertible 110 PG
"Wherever you go....There you are"

<a href="[s1166.photobucket.com]; target="_blank"><img src="[i1166.photobucket.com]; border="0" alt=" photo 045ef0c8-2087-4eac-8a5d-9aa0d575d5e0_zps9946d378.jpg"/></a>
<a href="[s1166.photobucket.com]; target="_blank"><img src="[i1166.photobucket.com]; border="0" alt=" photo e1227532-1d1b-4c27-b9b3-ab7c1e338ee9_zpsoelhfofz.jpg"/></a>



Edited 1 time(s). Last edit at 11/23/2012 12:35PM by jimmyo.

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Re: New Vacuum Advance
Date: November 23, 2012 12:47PM

There is a three digit number stamped on the arm of the V/A that corresponds to it's properties.

I think that number is detailed on the second pic that Jim posted.

Later Turbo retard unit is stamped 250 and has a ring on the pipe the hose fits to help hold it against the pressure.




Dan Davis ~ Pierce County, WA ~ CCF admin ~
CORSA +Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 Corsa 140 Coupe ~ ~ 1965 Monza 140/4 Convertible Sierra Tan/Fawn ~ 1964 Monza Spyder Convertible ~ 1960 Monza Ermine White/Red PG ++ ~ 1965 Monza 140/4 CoupeEvening Orchid w/ ivory/black interior ~ 1962 Monza Wagon 102/4 ~ 1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468



Edited 1 time(s). Last edit at 11/23/2012 12:56PM by 1966-Corsa-GT-180.

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Re: New Vacuum Advance
Posted by: jimmyo ()
Date: November 23, 2012 12:55PM

Yes the vac advance number is the 2nd chart 3digit vac advance number.

Jim O'Connor
45 miles north of The Bronx, N.Y.
1962 Greenbrier 110 4spd
1964 Monza Convertible 110 PG
"Wherever you go....There you are"

<a href="[s1166.photobucket.com]; target="_blank"><img src="[i1166.photobucket.com]; border="0" alt=" photo 045ef0c8-2087-4eac-8a5d-9aa0d575d5e0_zps9946d378.jpg"/></a>
<a href="[s1166.photobucket.com]; target="_blank"><img src="[i1166.photobucket.com]; border="0" alt=" photo e1227532-1d1b-4c27-b9b3-ab7c1e338ee9_zpsoelhfofz.jpg"/></a>

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Re: New Vacuum Advance
Posted by: vairchet ()
Date: November 23, 2012 01:21PM

Here's some older information concerning Corvair distributors. Following four pages pretty much coincides with previous photos (information gleaned from February 1984 edition of the Corvair Communique):

Some Corvair Guy in Ramona

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Re: New Vacuum Advance
Posted by: vairchet ()
Date: November 23, 2012 01:23PM

Last page:

Some Corvair Guy in Ramona

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Re: New Vacuum Advance
Posted by: Duane1967 ()
Date: November 23, 2012 02:58PM

I searched for Vacuum Advance before posting my question, and saw several of the charts many of you have posted. That is essentially why I asked, because it appeared that based on your distributor, and the hp and trans type, it takes a different unit. Based on what I've seen and what Matt has already said, not that many different units are currently available.

BUT, if you search online distributors, or if I go to Napa, it is safe to assume that if i go into Napa and ask for a vacuum advance for a 67 Corvair with the number represented in that chart, they won't have it, or be able to tell me there is any difference.

I saw matt's response, saying just buy one, and see how it works. Is that the best approach? I'm getting a slight surge feeling or sound at cruising speeds.
It doesn't feel like an engine miss, but with the cost of a new v.a., it sure seems like a good chance it might resolve the issue.

Or is it just as easy to wack it with a socket and a hammer, and that will fix it too. Are there instructions somewhere on how to do that?

Thanks!

Duane
1967 500 Coupe
Folsom, CA (Sacramento suburb)


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Re: New Vacuum Advance
Posted by: MattNall ()
Date: November 23, 2012 03:42PM

Whack it 1st.... then buy..

Test before whacking by pulling the hose off and plug it with a screw.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
...............110-PG.................................................Webered-Turbo

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Re: New Vacuum Advance
Posted by: steve c goodman ()
Date: November 23, 2012 08:49PM

Hello Duane: From what I have seen the quality control with the new advance canisters leaves a bit to be desired. In other words, no two work exactly the same. Couple that with the fact the vac in your engine may not be the same as the next car either and you have some interesting times adjusting it.

I test the advance canisters with my vac pump to get an idea how each one is moving, takes some time to do too. GOOD LUCK

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: New Vacuum Advance
Posted by: lgoodwin ()
Date: November 24, 2012 12:08AM

The only things that can go wrong are a leaky diaphragm and/or hose, a sticking advance mechanism inside the distributor or issue with the connection (V/A lever not on the lever coming out of dist).

Rather than hit it with a hammer and risk damaging something, may I suggest one or more of the following approaches to testing it?

TIMING LIGHT: With a timing light and engine warmed up and at correct idle speed,
1) Verify the initial timing is correct.
2) Speed engine up to 2000-3000 RPM (while speeding up, watch timing and verify that it is advancing), and hold engine speed at 2000-3000 RPM (not sure what it "idea" RPMs) and verify that timing HOLDS STEADY at a reasonable advance timing (look up the range for your year/engine/trans).
3) Let engine go back down to idle and verify that timing drops back to initial value without stopping in-between (indicates sticking).

SUCTION: Apply suction to vacuum advance hose (mouth works ok for this test) and verify that the lever moves to the right, stays there when holding suction, and moves back to the left when you release the suction.

HTH

<table align='center' width='0'>
<tr>
<td><img src='[www.automation-scs.com]; alt='1962 Corvair 900 sedan' width='190' /></td>
<td><img src='[corvaircenter.com]; alt='1967 Corvair Monza 140/4-speed' width='190' /></td>
<td><img src='[corvaircenter.com]; alt='1968 Corvair 500 coupe' width='190' /></td>
<td><img src='[www.automation-scs.com]; alt='1983 Mexican Mustang 5.0' width='190' /></td>
<td><a href='[www.automation-scs.com&]; target='_blank'></a></td>
</tr>
<tr>
<td align='center'><font size='1'>1962 900 sedan needs a home</font></td>
<td align='center'><font size='1'>1967 Monza 140/4-spd</font></td>
<td align='center'><font size='1'>1968 500 coupe (now my son's)</font></td>
<td align='center'><font size='1'>1983 Mexican Mustang 5.0</font></td>
</tr>
</table>

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Re: New Vacuum Advance
Posted by: vairchet ()
Date: November 24, 2012 01:31AM

Here's what I found at Autobone: [www.autozone.com]

Here's what I found at O'Really Auto Parts: [www.oreillyauto.com]

Here's what I found at NAPA: [www.napaonline.com]

Some Corvair Guy in Ramona

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Re: New Vacuum Advance
Posted by: Tom Z ()
Date: November 24, 2012 03:31AM

..I'd investigate your 'slight surge at cruise speeds' before you start "throwing parts at it" !! It sounds like the controlling vacuum TO the advance pod may be changing,or the (worn?) distrib bushing and gear (and points,etc) are causing a timing change,or it's a carb condition,,heck it could be the trans modulator and/or the vac line leaking!..

Tom Z,,Rochester NY

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Re: New Vacuum Advance
Posted by: matchlessmo ()
Date: November 24, 2012 04:19AM

i got mine from ebay= $4.86 free shipping [www.ebay.com]

. .

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Re: New Vacuum Advance
Posted by: Duane1967 ()
Date: November 24, 2012 10:43PM

I agree. Guessing at parts is sometimes like peeing in a fan, BUT, if it only cost
$4.50 to $10.00, and it's a simple, take off, put back on, sometimes it just makes me feel good to give it a gamble. It feels even better if it works. Sucks when there is no change. I saw all the different part numbers in the charts posted, and knew that the ones available at O'Reilly, Autozone and Napa would be a generic one. That's why I asked can you just go buy one or were they different.

The surge doesn't seem to cause a loss of power. It's more annoying than anything else.

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Re: New Vacuum Advance
Posted by: lgoodwin ()
Date: November 24, 2012 11:06PM

Duane1967 Wrote:
-------------------------------------------------------
> The surge doesn't seem to cause a loss of power.
> It's more annoying than anything else.

When you say "surge", do you mean
a) that with your foot on the pedal and holding it there, the engine (and vehicle) speeds up?
b) that the throttle response varies, sometimes accelerates faster than expected), but is not consistent?
c) something else?

BTW, the BWD on O'Reilly and the Echlin on NAPA both have the pointing tab like the one on my 67 Monza with a 140 transplanted into it, but the other end on BOTH of those has TWO SCREW HOLES. Corvairs only have one hole on that end. You may have to modify it to make it work on a Corvair.

<table align='center' width='0'>
<tr>
<td><img src='[www.automation-scs.com]; alt='1962 Corvair 900 sedan' width='190' /></td>
<td><img src='[corvaircenter.com]; alt='1967 Corvair Monza 140/4-speed' width='190' /></td>
<td><img src='[corvaircenter.com]; alt='1968 Corvair 500 coupe' width='190' /></td>
<td><img src='[www.automation-scs.com]; alt='1983 Mexican Mustang 5.0' width='190' /></td>
<td><a href='[www.automation-scs.com&]; target='_blank'></a></td>
</tr>
<tr>
<td align='center'><font size='1'>1962 900 sedan needs a home</font></td>
<td align='center'><font size='1'>1967 Monza 140/4-spd</font></td>
<td align='center'><font size='1'>1968 500 coupe (now my son's)</font></td>
<td align='center'><font size='1'>1983 Mexican Mustang 5.0</font></td>
</tr>
</table>

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Re: New Vacuum Advance
Posted by: RobertC ()
Date: November 24, 2012 11:53PM

As stated there are only a couple options available now - versus the "many" that GM used...

There aer companies that rebuild vacuum advances. I have no idea how close they will come to GM spedcs.

Here is one company in Oregon... you could call and see what they tell you.

[philbingroup.com]

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Re: New Vacuum Advance
Posted by: Duane1967 ()
Date: November 25, 2012 07:51AM

lgoodwin wrote:

When you say "surge", do you mean
a) that with your foot on the pedal and holding it there, the engine (and vehicle) speeds up?
b) that the throttle response varies, sometimes accelerates faster than expected), but is not consistent?
c) something else?

It's more like "c", something else. Cruising at 65 mph, on a flat stretch of the highway, I can hear the engine hum change like it is missing, but it's not an
ignition or firing miss, it's more just like a sound. If there is a loss of power, it's so subtle, it's actually just annoying. And it gives me the impression that something is wrong, and I'm getting ready to be reminded why I should have paid more attention to it because it will leave me stranded some where. I've walked before. Luckily, never been towed.

Duane
1967 500 Coupe
Folsom, CA (Sacramento suburb)


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Re: New Vacuum Advance
Posted by: jimmyo ()
Date: November 25, 2012 08:56AM

I've been following this tread closely because recently if I back off the throttle a little at cruising speed, I can feel a slight dead spot, Not a miss, just a slight drop in power. I was thinking Vac advance myself, because I think maybe the advance is not responding properly to the drop in vac pressure. I hate that I can't find the specs on the replacement units flaps sellsangry smiley .Also what is also complicating the picture is I know I'm running the wrong distributor. I have a 140 dist (330) on my 110 engine (319) The 140 dist full mechanical advance advance is 18degrees at 2800rpm. The 110 Dist is 20 degrees at 4800rpm. It's not a big problem, but it's the little things that make me nuts. I'm going to try the vc150 they sell for fun, just to see what happens. I don't mind having spare parts. I will try testing the old one before hand, to see if I can detect a problem.

Jim O'Connor
45 miles north of The Bronx, N.Y.
1962 Greenbrier 110 4spd
1964 Monza Convertible 110 PG
"Wherever you go....There you are"

<a href="[s1166.photobucket.com]; target="_blank"><img src="[i1166.photobucket.com]; border="0" alt=" photo 045ef0c8-2087-4eac-8a5d-9aa0d575d5e0_zps9946d378.jpg"/></a>
<a href="[s1166.photobucket.com]; target="_blank"><img src="[i1166.photobucket.com]; border="0" alt=" photo e1227532-1d1b-4c27-b9b3-ab7c1e338ee9_zpsoelhfofz.jpg"/></a>

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Re: New Vacuum Advance
Posted by: Duane1967 ()
Date: November 25, 2012 11:51AM

as far as i know, I have the correct distributor and va for my car.

I drove it 15 miles this morning, and observed very closely the symptoms I had previously described. It's not really a surge. The engine noise/rumble stays exactly the same, but the car almost seems like it is hitting a gust of wind, and I can feel the resistsance. It was not windy. So it's not really a surge, but a feeling of resistance on my forward motion. And not enough to slow my speed at all. I can just feel it. It's annoying. And worse of all, it gives me the feeling something is wrong, and it reduces my confidence in the car for longer distance drives. So far, never been towed.

Duane
1967 500 Coupe
Folsom, CA (Sacramento suburb)


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